root/src/add-ons/kernel/drivers/network/ether/atheros813x/dev/alc/if_alc.c
/*-
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * Copyright (c) 2009, Pyun YongHyeon <yongari@FreeBSD.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice unmodified, this list of conditions, and the following
 *    disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/* Driver for Atheros AR813x/AR815x PCIe Ethernet. */

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bus.h>
#include <sys/endian.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/module.h>
#include <sys/mutex.h>
#include <sys/rman.h>
#include <sys/queue.h>
#include <sys/socket.h>
#include <sys/sockio.h>
#include <sys/sysctl.h>
#include <sys/taskqueue.h>

#include <net/bpf.h>
#include <net/debugnet.h>
#include <net/if.h>
#include <net/if_var.h>
#include <net/if_arp.h>
#include <net/ethernet.h>
#include <net/if_dl.h>
#include <net/if_llc.h>
#include <net/if_media.h>
#include <net/if_types.h>
#include <net/if_vlan_var.h>

#include <netinet/in.h>
#include <netinet/in_systm.h>
#include <netinet/ip.h>
#include <netinet/tcp.h>

#include <dev/mii/mii.h>
#include <dev/mii/miivar.h>

#include <dev/pci/pcireg.h>
#include <dev/pci/pcivar.h>

#include <machine/bus.h>
#include <machine/in_cksum.h>

#include <dev/alc/if_alcreg.h>
#include <dev/alc/if_alcvar.h>

/* "device miibus" required.  See GENERIC if you get errors here. */
#include "miibus_if.h"
#undef ALC_USE_CUSTOM_CSUM

#ifdef ALC_USE_CUSTOM_CSUM
#define ALC_CSUM_FEATURES       (CSUM_TCP | CSUM_UDP)
#else
#define ALC_CSUM_FEATURES       (CSUM_IP | CSUM_TCP | CSUM_UDP)
#endif

MODULE_DEPEND(alc, pci, 1, 1, 1);
MODULE_DEPEND(alc, ether, 1, 1, 1);
MODULE_DEPEND(alc, miibus, 1, 1, 1);

/* Tunables. */
static int msi_disable = 0;
TUNABLE_INT("hw.alc.msi_disable", &msi_disable);

/*
 * The default value of msix_disable is 2, which means to decide whether to
 * enable MSI-X in alc_attach() depending on the card type.  The operator can
 * set this to 0 or 1 to override the default.
 */
static int msix_disable = 2;
TUNABLE_INT("hw.alc.msix_disable", &msix_disable);

/*
 * Devices supported by this driver.
 */
static struct alc_ident alc_ident_table[] = {
        { VENDORID_ATHEROS, DEVICEID_ATHEROS_AR8131, 9 * 1024,
                "Atheros AR8131 PCIe Gigabit Ethernet" },
        { VENDORID_ATHEROS, DEVICEID_ATHEROS_AR8132, 9 * 1024,
                "Atheros AR8132 PCIe Fast Ethernet" },
        { VENDORID_ATHEROS, DEVICEID_ATHEROS_AR8151, 6 * 1024,
                "Atheros AR8151 v1.0 PCIe Gigabit Ethernet" },
        { VENDORID_ATHEROS, DEVICEID_ATHEROS_AR8151_V2, 6 * 1024,
                "Atheros AR8151 v2.0 PCIe Gigabit Ethernet" },
        { VENDORID_ATHEROS, DEVICEID_ATHEROS_AR8152_B, 6 * 1024,
                "Atheros AR8152 v1.1 PCIe Fast Ethernet" },
        { VENDORID_ATHEROS, DEVICEID_ATHEROS_AR8152_B2, 6 * 1024,
                "Atheros AR8152 v2.0 PCIe Fast Ethernet" },
        { VENDORID_ATHEROS, DEVICEID_ATHEROS_AR8161, 9 * 1024,
                "Atheros AR8161 PCIe Gigabit Ethernet" },
        { VENDORID_ATHEROS, DEVICEID_ATHEROS_AR8162, 9 * 1024,
                "Atheros AR8162 PCIe Fast Ethernet" },
        { VENDORID_ATHEROS, DEVICEID_ATHEROS_AR8171, 9 * 1024,
                "Atheros AR8171 PCIe Gigabit Ethernet" },
        { VENDORID_ATHEROS, DEVICEID_ATHEROS_AR8172, 9 * 1024,
                "Atheros AR8172 PCIe Fast Ethernet" },
        { VENDORID_ATHEROS, DEVICEID_ATHEROS_E2200, 9 * 1024,
                "Killer E2200 Gigabit Ethernet" },
        { VENDORID_ATHEROS, DEVICEID_ATHEROS_E2400, 9 * 1024,
                "Killer E2400 Gigabit Ethernet" },
        { VENDORID_ATHEROS, DEVICEID_ATHEROS_E2500, 9 * 1024,
                "Killer E2500 Gigabit Ethernet" },
        { 0, 0, 0, NULL}
};

static void     alc_aspm(struct alc_softc *, int, int);
static void     alc_aspm_813x(struct alc_softc *, int);
static void     alc_aspm_816x(struct alc_softc *, int);
static int      alc_attach(device_t);
static int      alc_check_boundary(struct alc_softc *);
static void     alc_config_msi(struct alc_softc *);
static int      alc_detach(device_t);
static void     alc_disable_l0s_l1(struct alc_softc *);
static int      alc_dma_alloc(struct alc_softc *);
static void     alc_dma_free(struct alc_softc *);
static void     alc_dmamap_cb(void *, bus_dma_segment_t *, int, int);
static void     alc_dsp_fixup(struct alc_softc *, int);
static int      alc_encap(struct alc_softc *, struct mbuf **);
static struct alc_ident *
                alc_find_ident(device_t);
#ifndef __NO_STRICT_ALIGNMENT
static struct mbuf *
                alc_fixup_rx(if_t, struct mbuf *);
#endif
static void     alc_get_macaddr(struct alc_softc *);
static void     alc_get_macaddr_813x(struct alc_softc *);
static void     alc_get_macaddr_816x(struct alc_softc *);
static void     alc_get_macaddr_par(struct alc_softc *);
static void     alc_init(void *);
static void     alc_init_cmb(struct alc_softc *);
static void     alc_init_locked(struct alc_softc *);
static void     alc_init_rr_ring(struct alc_softc *);
static int      alc_init_rx_ring(struct alc_softc *);
static void     alc_init_smb(struct alc_softc *);
static void     alc_init_tx_ring(struct alc_softc *);
static void     alc_int_task(void *, int);
static int      alc_intr(void *);
static int      alc_ioctl(if_t, u_long, caddr_t);
static void     alc_mac_config(struct alc_softc *);
static uint32_t alc_mii_readreg_813x(struct alc_softc *, int, int);
static uint32_t alc_mii_readreg_816x(struct alc_softc *, int, int);
static uint32_t alc_mii_writereg_813x(struct alc_softc *, int, int, int);
static uint32_t alc_mii_writereg_816x(struct alc_softc *, int, int, int);
static int      alc_miibus_readreg(device_t, int, int);
static void     alc_miibus_statchg(device_t);
static int      alc_miibus_writereg(device_t, int, int, int);
static uint32_t alc_miidbg_readreg(struct alc_softc *, int);
static uint32_t alc_miidbg_writereg(struct alc_softc *, int, int);
static uint32_t alc_miiext_readreg(struct alc_softc *, int, int);
static uint32_t alc_miiext_writereg(struct alc_softc *, int, int, int);
static int      alc_mediachange(if_t);
static int      alc_mediachange_locked(struct alc_softc *);
static void     alc_mediastatus(if_t, struct ifmediareq *);
static int      alc_newbuf(struct alc_softc *, struct alc_rxdesc *);
static void     alc_osc_reset(struct alc_softc *);
static void     alc_phy_down(struct alc_softc *);
static void     alc_phy_reset(struct alc_softc *);
static void     alc_phy_reset_813x(struct alc_softc *);
static void     alc_phy_reset_816x(struct alc_softc *);
static int      alc_probe(device_t);
static void     alc_reset(struct alc_softc *);
static int      alc_resume(device_t);
static void     alc_rxeof(struct alc_softc *, struct rx_rdesc *);
static int      alc_rxintr(struct alc_softc *, int);
static void     alc_rxfilter(struct alc_softc *);
static void     alc_rxvlan(struct alc_softc *);
static void     alc_setlinkspeed(struct alc_softc *);
static void     alc_setwol(struct alc_softc *);
static void     alc_setwol_813x(struct alc_softc *);
static void     alc_setwol_816x(struct alc_softc *);
static int      alc_shutdown(device_t);
static void     alc_start(if_t);
static void     alc_start_locked(if_t);
static void     alc_start_queue(struct alc_softc *);
static void     alc_start_tx(struct alc_softc *);
static void     alc_stats_clear(struct alc_softc *);
static void     alc_stats_update(struct alc_softc *);
static void     alc_stop(struct alc_softc *);
static void     alc_stop_mac(struct alc_softc *);
static void     alc_stop_queue(struct alc_softc *);
static int      alc_suspend(device_t);
static void     alc_sysctl_node(struct alc_softc *);
static void     alc_tick(void *);
static void     alc_txeof(struct alc_softc *);
static void     alc_watchdog(struct alc_softc *);
static int      sysctl_int_range(SYSCTL_HANDLER_ARGS, int, int);
static int      sysctl_hw_alc_proc_limit(SYSCTL_HANDLER_ARGS);
static int      sysctl_hw_alc_int_mod(SYSCTL_HANDLER_ARGS);

DEBUGNET_DEFINE(alc);

static device_method_t alc_methods[] = {
        /* Device interface. */
        DEVMETHOD(device_probe,         alc_probe),
        DEVMETHOD(device_attach,        alc_attach),
        DEVMETHOD(device_detach,        alc_detach),
        DEVMETHOD(device_shutdown,      alc_shutdown),
        DEVMETHOD(device_suspend,       alc_suspend),
        DEVMETHOD(device_resume,        alc_resume),

        /* MII interface. */
        DEVMETHOD(miibus_readreg,       alc_miibus_readreg),
        DEVMETHOD(miibus_writereg,      alc_miibus_writereg),
        DEVMETHOD(miibus_statchg,       alc_miibus_statchg),

        DEVMETHOD_END
};

static driver_t alc_driver = {
        "alc",
        alc_methods,
        sizeof(struct alc_softc)
};

DRIVER_MODULE(alc, pci, alc_driver, 0, 0);
MODULE_PNP_INFO("U16:vendor;U16:device", pci, alc, alc_ident_table,
    nitems(alc_ident_table) - 1);
DRIVER_MODULE(miibus, alc, miibus_driver, 0, 0);

static struct resource_spec alc_res_spec_mem[] = {
        { SYS_RES_MEMORY,       PCIR_BAR(0),    RF_ACTIVE },
        { -1,                   0,              0 }
};

static struct resource_spec alc_irq_spec_legacy[] = {
        { SYS_RES_IRQ,          0,              RF_ACTIVE | RF_SHAREABLE },
        { -1,                   0,              0 }
};

static struct resource_spec alc_irq_spec_msi[] = {
        { SYS_RES_IRQ,          1,              RF_ACTIVE },
        { -1,                   0,              0 }
};

static struct resource_spec alc_irq_spec_msix[] = {
        { SYS_RES_IRQ,          1,              RF_ACTIVE },
        { -1,                   0,              0 }
};

static uint32_t alc_dma_burst[] = { 128, 256, 512, 1024, 2048, 4096, 0, 0 };

static int
alc_miibus_readreg(device_t dev, int phy, int reg)
{
        struct alc_softc *sc;
        int v;

        sc = device_get_softc(dev);
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0)
                v = alc_mii_readreg_816x(sc, phy, reg);
        else
                v = alc_mii_readreg_813x(sc, phy, reg);
        return (v);
}

static uint32_t
alc_mii_readreg_813x(struct alc_softc *sc, int phy, int reg)
{
        uint32_t v;
        int i;

        /*
         * For AR8132 fast ethernet controller, do not report 1000baseT
         * capability to mii(4). Even though AR8132 uses the same
         * model/revision number of F1 gigabit PHY, the PHY has no
         * ability to establish 1000baseT link.
         */
        if ((sc->alc_flags & ALC_FLAG_FASTETHER) != 0 &&
            reg == MII_EXTSR)
                return (0);

        CSR_WRITE_4(sc, ALC_MDIO, MDIO_OP_EXECUTE | MDIO_OP_READ |
            MDIO_SUP_PREAMBLE | MDIO_CLK_25_4 | MDIO_REG_ADDR(reg));
        for (i = ALC_PHY_TIMEOUT; i > 0; i--) {
                DELAY(5);
                v = CSR_READ_4(sc, ALC_MDIO);
                if ((v & (MDIO_OP_EXECUTE | MDIO_OP_BUSY)) == 0)
                        break;
        }

        if (i == 0) {
                device_printf(sc->alc_dev, "phy read timeout : %d\n", reg);
                return (0);
        }

        return ((v & MDIO_DATA_MASK) >> MDIO_DATA_SHIFT);
}

static uint32_t
alc_mii_readreg_816x(struct alc_softc *sc, int phy, int reg)
{
        uint32_t clk, v;
        int i;

        if ((sc->alc_flags & ALC_FLAG_LINK) != 0)
                clk = MDIO_CLK_25_128;
        else
                clk = MDIO_CLK_25_4;
        CSR_WRITE_4(sc, ALC_MDIO, MDIO_OP_EXECUTE | MDIO_OP_READ |
            MDIO_SUP_PREAMBLE | clk | MDIO_REG_ADDR(reg));
        for (i = ALC_PHY_TIMEOUT; i > 0; i--) {
                DELAY(5);
                v = CSR_READ_4(sc, ALC_MDIO);
                if ((v & MDIO_OP_BUSY) == 0)
                        break;
        }

        if (i == 0) {
                device_printf(sc->alc_dev, "phy read timeout : %d\n", reg);
                return (0);
        }

        return ((v & MDIO_DATA_MASK) >> MDIO_DATA_SHIFT);
}

static int
alc_miibus_writereg(device_t dev, int phy, int reg, int val)
{
        struct alc_softc *sc;
        int v;

        sc = device_get_softc(dev);
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0)
                v = alc_mii_writereg_816x(sc, phy, reg, val);
        else
                v = alc_mii_writereg_813x(sc, phy, reg, val);
        return (v);
}

static uint32_t
alc_mii_writereg_813x(struct alc_softc *sc, int phy, int reg, int val)
{
        uint32_t v;
        int i;

        CSR_WRITE_4(sc, ALC_MDIO, MDIO_OP_EXECUTE | MDIO_OP_WRITE |
            (val & MDIO_DATA_MASK) << MDIO_DATA_SHIFT |
            MDIO_SUP_PREAMBLE | MDIO_CLK_25_4 | MDIO_REG_ADDR(reg));
        for (i = ALC_PHY_TIMEOUT; i > 0; i--) {
                DELAY(5);
                v = CSR_READ_4(sc, ALC_MDIO);
                if ((v & (MDIO_OP_EXECUTE | MDIO_OP_BUSY)) == 0)
                        break;
        }

        if (i == 0)
                device_printf(sc->alc_dev, "phy write timeout : %d\n", reg);

        return (0);
}

static uint32_t
alc_mii_writereg_816x(struct alc_softc *sc, int phy, int reg, int val)
{
        uint32_t clk, v;
        int i;

        if ((sc->alc_flags & ALC_FLAG_LINK) != 0)
                clk = MDIO_CLK_25_128;
        else
                clk = MDIO_CLK_25_4;
        CSR_WRITE_4(sc, ALC_MDIO, MDIO_OP_EXECUTE | MDIO_OP_WRITE |
            ((val & MDIO_DATA_MASK) << MDIO_DATA_SHIFT) | MDIO_REG_ADDR(reg) |
            MDIO_SUP_PREAMBLE | clk);
        for (i = ALC_PHY_TIMEOUT; i > 0; i--) {
                DELAY(5);
                v = CSR_READ_4(sc, ALC_MDIO);
                if ((v & MDIO_OP_BUSY) == 0)
                        break;
        }

        if (i == 0)
                device_printf(sc->alc_dev, "phy write timeout : %d\n", reg);

        return (0);
}

static void
alc_miibus_statchg(device_t dev)
{
        struct alc_softc *sc;
        struct mii_data *mii;
        if_t ifp;
        uint32_t reg;

        sc = device_get_softc(dev);

        mii = device_get_softc(sc->alc_miibus);
        ifp = sc->alc_ifp;
        if (mii == NULL || ifp == NULL ||
            (if_getdrvflags(ifp) & IFF_DRV_RUNNING) == 0)
                return;

        sc->alc_flags &= ~ALC_FLAG_LINK;
        if ((mii->mii_media_status & (IFM_ACTIVE | IFM_AVALID)) ==
            (IFM_ACTIVE | IFM_AVALID)) {
                switch (IFM_SUBTYPE(mii->mii_media_active)) {
                case IFM_10_T:
                case IFM_100_TX:
                        sc->alc_flags |= ALC_FLAG_LINK;
                        break;
                case IFM_1000_T:
                        if ((sc->alc_flags & ALC_FLAG_FASTETHER) == 0)
                                sc->alc_flags |= ALC_FLAG_LINK;
                        break;
                default:
                        break;
                }
        }
        /* Stop Rx/Tx MACs. */
        alc_stop_mac(sc);

        /* Program MACs with resolved speed/duplex/flow-control. */
        if ((sc->alc_flags & ALC_FLAG_LINK) != 0) {
                alc_start_queue(sc);
                alc_mac_config(sc);
                /* Re-enable Tx/Rx MACs. */
                reg = CSR_READ_4(sc, ALC_MAC_CFG);
                reg |= MAC_CFG_TX_ENB | MAC_CFG_RX_ENB;
                CSR_WRITE_4(sc, ALC_MAC_CFG, reg);
        }
        alc_aspm(sc, 0, IFM_SUBTYPE(mii->mii_media_active));
        alc_dsp_fixup(sc, IFM_SUBTYPE(mii->mii_media_active));
}

static uint32_t
alc_miidbg_readreg(struct alc_softc *sc, int reg)
{

        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr, ALC_MII_DBG_ADDR,
            reg);
        return (alc_miibus_readreg(sc->alc_dev, sc->alc_phyaddr,
            ALC_MII_DBG_DATA));
}

static uint32_t
alc_miidbg_writereg(struct alc_softc *sc, int reg, int val)
{

        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr, ALC_MII_DBG_ADDR,
            reg);
        return (alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
            ALC_MII_DBG_DATA, val));
}

static uint32_t
alc_miiext_readreg(struct alc_softc *sc, int devaddr, int reg)
{
        uint32_t clk, v;
        int i;

        CSR_WRITE_4(sc, ALC_EXT_MDIO, EXT_MDIO_REG(reg) |
            EXT_MDIO_DEVADDR(devaddr));
        if ((sc->alc_flags & ALC_FLAG_LINK) != 0)
                clk = MDIO_CLK_25_128;
        else
                clk = MDIO_CLK_25_4;
        CSR_WRITE_4(sc, ALC_MDIO, MDIO_OP_EXECUTE | MDIO_OP_READ |
            MDIO_SUP_PREAMBLE | clk | MDIO_MODE_EXT);
        for (i = ALC_PHY_TIMEOUT; i > 0; i--) {
                DELAY(5);
                v = CSR_READ_4(sc, ALC_MDIO);
                if ((v & MDIO_OP_BUSY) == 0)
                        break;
        }

        if (i == 0) {
                device_printf(sc->alc_dev, "phy ext read timeout : %d, %d\n",
                    devaddr, reg);
                return (0);
        }

        return ((v & MDIO_DATA_MASK) >> MDIO_DATA_SHIFT);
}

static uint32_t
alc_miiext_writereg(struct alc_softc *sc, int devaddr, int reg, int val)
{
        uint32_t clk, v;
        int i;

        CSR_WRITE_4(sc, ALC_EXT_MDIO, EXT_MDIO_REG(reg) |
            EXT_MDIO_DEVADDR(devaddr));
        if ((sc->alc_flags & ALC_FLAG_LINK) != 0)
                clk = MDIO_CLK_25_128;
        else
                clk = MDIO_CLK_25_4;
        CSR_WRITE_4(sc, ALC_MDIO, MDIO_OP_EXECUTE | MDIO_OP_WRITE |
            ((val & MDIO_DATA_MASK) << MDIO_DATA_SHIFT) |
            MDIO_SUP_PREAMBLE | clk | MDIO_MODE_EXT);
        for (i = ALC_PHY_TIMEOUT; i > 0; i--) {
                DELAY(5);
                v = CSR_READ_4(sc, ALC_MDIO);
                if ((v & MDIO_OP_BUSY) == 0)
                        break;
        }

        if (i == 0)
                device_printf(sc->alc_dev, "phy ext write timeout : %d, %d\n",
                    devaddr, reg);

        return (0);
}

static void
alc_dsp_fixup(struct alc_softc *sc, int media)
{
        uint16_t agc, len, val;

        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0)
                return;
        if (AR816X_REV(sc->alc_rev) >= AR816X_REV_C0)
                return;

        /*
         * Vendor PHY magic.
         * 1000BT/AZ, wrong cable length
         */
        if ((sc->alc_flags & ALC_FLAG_LINK) != 0) {
                len = alc_miiext_readreg(sc, MII_EXT_PCS, MII_EXT_CLDCTL6);
                len = (len >> EXT_CLDCTL6_CAB_LEN_SHIFT) &
                    EXT_CLDCTL6_CAB_LEN_MASK;
                agc = alc_miidbg_readreg(sc, MII_DBG_AGC);
                agc = (agc >> DBG_AGC_2_VGA_SHIFT) & DBG_AGC_2_VGA_MASK;
                if ((media == IFM_1000_T && len > EXT_CLDCTL6_CAB_LEN_SHORT1G &&
                    agc > DBG_AGC_LONG1G_LIMT) ||
                    (media == IFM_100_TX && len > DBG_AGC_LONG100M_LIMT &&
                    agc > DBG_AGC_LONG1G_LIMT)) {
                        alc_miidbg_writereg(sc, MII_DBG_AZ_ANADECT,
                            DBG_AZ_ANADECT_LONG);
                        val = alc_miiext_readreg(sc, MII_EXT_ANEG,
                            MII_EXT_ANEG_AFE);
                        val |= ANEG_AFEE_10BT_100M_TH;
                        alc_miiext_writereg(sc, MII_EXT_ANEG, MII_EXT_ANEG_AFE,
                            val);
                } else {
                        alc_miidbg_writereg(sc, MII_DBG_AZ_ANADECT,
                            DBG_AZ_ANADECT_DEFAULT);
                        val = alc_miiext_readreg(sc, MII_EXT_ANEG,
                            MII_EXT_ANEG_AFE);
                        val &= ~ANEG_AFEE_10BT_100M_TH;
                        alc_miiext_writereg(sc, MII_EXT_ANEG, MII_EXT_ANEG_AFE,
                            val);
                }
                if ((sc->alc_flags & ALC_FLAG_LINK_WAR) != 0 &&
                    AR816X_REV(sc->alc_rev) == AR816X_REV_B0) {
                        if (media == IFM_1000_T) {
                                /*
                                 * Giga link threshold, raise the tolerance of
                                 * noise 50%.
                                 */
                                val = alc_miidbg_readreg(sc, MII_DBG_MSE20DB);
                                val &= ~DBG_MSE20DB_TH_MASK;
                                val |= (DBG_MSE20DB_TH_HI <<
                                    DBG_MSE20DB_TH_SHIFT);
                                alc_miidbg_writereg(sc, MII_DBG_MSE20DB, val);
                        } else if (media == IFM_100_TX)
                                alc_miidbg_writereg(sc, MII_DBG_MSE16DB,
                                    DBG_MSE16DB_UP);
                }
        } else {
                val = alc_miiext_readreg(sc, MII_EXT_ANEG, MII_EXT_ANEG_AFE);
                val &= ~ANEG_AFEE_10BT_100M_TH;
                alc_miiext_writereg(sc, MII_EXT_ANEG, MII_EXT_ANEG_AFE, val);
                if ((sc->alc_flags & ALC_FLAG_LINK_WAR) != 0 &&
                    AR816X_REV(sc->alc_rev) == AR816X_REV_B0) {
                        alc_miidbg_writereg(sc, MII_DBG_MSE16DB,
                            DBG_MSE16DB_DOWN);
                        val = alc_miidbg_readreg(sc, MII_DBG_MSE20DB);
                        val &= ~DBG_MSE20DB_TH_MASK;
                        val |= (DBG_MSE20DB_TH_DEFAULT << DBG_MSE20DB_TH_SHIFT);
                        alc_miidbg_writereg(sc, MII_DBG_MSE20DB, val);
                }
        }
}

static void
alc_mediastatus(if_t ifp, struct ifmediareq *ifmr)
{
        struct alc_softc *sc;
        struct mii_data *mii;

        sc = if_getsoftc(ifp);
        ALC_LOCK(sc);
        if ((if_getflags(ifp) & IFF_UP) == 0) {
                ALC_UNLOCK(sc);
                return;
        }
        mii = device_get_softc(sc->alc_miibus);

        mii_pollstat(mii);
        ifmr->ifm_status = mii->mii_media_status;
        ifmr->ifm_active = mii->mii_media_active;
        ALC_UNLOCK(sc);
}

static int
alc_mediachange(if_t ifp)
{
        struct alc_softc *sc;
        int error;

        sc = if_getsoftc(ifp);
        ALC_LOCK(sc);
        error = alc_mediachange_locked(sc);
        ALC_UNLOCK(sc);

        return (error);
}

static int
alc_mediachange_locked(struct alc_softc *sc)
{
        struct mii_data *mii;
        struct mii_softc *miisc;
        int error;

        ALC_LOCK_ASSERT(sc);

        mii = device_get_softc(sc->alc_miibus);
        LIST_FOREACH(miisc, &mii->mii_phys, mii_list)
                PHY_RESET(miisc);
        error = mii_mediachg(mii);

        return (error);
}

static struct alc_ident *
alc_find_ident(device_t dev)
{
        struct alc_ident *ident;
        uint16_t vendor, devid;

        vendor = pci_get_vendor(dev);
        devid = pci_get_device(dev);
        for (ident = alc_ident_table; ident->name != NULL; ident++) {
                if (vendor == ident->vendorid && devid == ident->deviceid)
                        return (ident);
        }

        return (NULL);
}

static int
alc_probe(device_t dev)
{
        struct alc_ident *ident;

        ident = alc_find_ident(dev);
        if (ident != NULL) {
                device_set_desc(dev, ident->name);
                return (BUS_PROBE_DEFAULT);
        }

        return (ENXIO);
}

static void
alc_get_macaddr(struct alc_softc *sc)
{

        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0)
                alc_get_macaddr_816x(sc);
        else
                alc_get_macaddr_813x(sc);
}

static void
alc_get_macaddr_813x(struct alc_softc *sc)
{
        uint32_t opt;
        uint16_t val;
        int eeprom, i;

        eeprom = 0;
        opt = CSR_READ_4(sc, ALC_OPT_CFG);
        if ((CSR_READ_4(sc, ALC_MASTER_CFG) & MASTER_OTP_SEL) != 0 &&
            (CSR_READ_4(sc, ALC_TWSI_DEBUG) & TWSI_DEBUG_DEV_EXIST) != 0) {
                /*
                 * EEPROM found, let TWSI reload EEPROM configuration.
                 * This will set ethernet address of controller.
                 */
                eeprom++;
                switch (sc->alc_ident->deviceid) {
                case DEVICEID_ATHEROS_AR8131:
                case DEVICEID_ATHEROS_AR8132:
                        if ((opt & OPT_CFG_CLK_ENB) == 0) {
                                opt |= OPT_CFG_CLK_ENB;
                                CSR_WRITE_4(sc, ALC_OPT_CFG, opt);
                                CSR_READ_4(sc, ALC_OPT_CFG);
                                DELAY(1000);
                        }
                        break;
                case DEVICEID_ATHEROS_AR8151:
                case DEVICEID_ATHEROS_AR8151_V2:
                case DEVICEID_ATHEROS_AR8152_B:
                case DEVICEID_ATHEROS_AR8152_B2:
                        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
                            ALC_MII_DBG_ADDR, 0x00);
                        val = alc_miibus_readreg(sc->alc_dev, sc->alc_phyaddr,
                            ALC_MII_DBG_DATA);
                        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
                            ALC_MII_DBG_DATA, val & 0xFF7F);
                        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
                            ALC_MII_DBG_ADDR, 0x3B);
                        val = alc_miibus_readreg(sc->alc_dev, sc->alc_phyaddr,
                            ALC_MII_DBG_DATA);
                        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
                            ALC_MII_DBG_DATA, val | 0x0008);
                        DELAY(20);
                        break;
                }

                CSR_WRITE_4(sc, ALC_LTSSM_ID_CFG,
                    CSR_READ_4(sc, ALC_LTSSM_ID_CFG) & ~LTSSM_ID_WRO_ENB);
                CSR_WRITE_4(sc, ALC_WOL_CFG, 0);
                CSR_READ_4(sc, ALC_WOL_CFG);

                CSR_WRITE_4(sc, ALC_TWSI_CFG, CSR_READ_4(sc, ALC_TWSI_CFG) |
                    TWSI_CFG_SW_LD_START);
                for (i = 100; i > 0; i--) {
                        DELAY(1000);
                        if ((CSR_READ_4(sc, ALC_TWSI_CFG) &
                            TWSI_CFG_SW_LD_START) == 0)
                                break;
                }
                if (i == 0)
                        device_printf(sc->alc_dev,
                            "reloading EEPROM timeout!\n");
        } else {
                if (bootverbose)
                        device_printf(sc->alc_dev, "EEPROM not found!\n");
        }
        if (eeprom != 0) {
                switch (sc->alc_ident->deviceid) {
                case DEVICEID_ATHEROS_AR8131:
                case DEVICEID_ATHEROS_AR8132:
                        if ((opt & OPT_CFG_CLK_ENB) != 0) {
                                opt &= ~OPT_CFG_CLK_ENB;
                                CSR_WRITE_4(sc, ALC_OPT_CFG, opt);
                                CSR_READ_4(sc, ALC_OPT_CFG);
                                DELAY(1000);
                        }
                        break;
                case DEVICEID_ATHEROS_AR8151:
                case DEVICEID_ATHEROS_AR8151_V2:
                case DEVICEID_ATHEROS_AR8152_B:
                case DEVICEID_ATHEROS_AR8152_B2:
                        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
                            ALC_MII_DBG_ADDR, 0x00);
                        val = alc_miibus_readreg(sc->alc_dev, sc->alc_phyaddr,
                            ALC_MII_DBG_DATA);
                        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
                            ALC_MII_DBG_DATA, val | 0x0080);
                        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
                            ALC_MII_DBG_ADDR, 0x3B);
                        val = alc_miibus_readreg(sc->alc_dev, sc->alc_phyaddr,
                            ALC_MII_DBG_DATA);
                        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
                            ALC_MII_DBG_DATA, val & 0xFFF7);
                        DELAY(20);
                        break;
                }
        }

        alc_get_macaddr_par(sc);
}

static void
alc_get_macaddr_816x(struct alc_softc *sc)
{
        uint32_t reg;
        int i, reloaded;

        reloaded = 0;
        /* Try to reload station address via TWSI. */
        for (i = 100; i > 0; i--) {
                reg = CSR_READ_4(sc, ALC_SLD);
                if ((reg & (SLD_PROGRESS | SLD_START)) == 0)
                        break;
                DELAY(1000);
        }
        if (i != 0) {
                CSR_WRITE_4(sc, ALC_SLD, reg | SLD_START);
                for (i = 100; i > 0; i--) {
                        DELAY(1000);
                        reg = CSR_READ_4(sc, ALC_SLD);
                        if ((reg & SLD_START) == 0)
                                break;
                }
                if (i != 0)
                        reloaded++;
                else if (bootverbose)
                        device_printf(sc->alc_dev,
                            "reloading station address via TWSI timed out!\n");
        }

        /* Try to reload station address from EEPROM or FLASH. */
        if (reloaded == 0) {
                reg = CSR_READ_4(sc, ALC_EEPROM_LD);
                if ((reg & (EEPROM_LD_EEPROM_EXIST |
                    EEPROM_LD_FLASH_EXIST)) != 0) {
                        for (i = 100; i > 0; i--) {
                                reg = CSR_READ_4(sc, ALC_EEPROM_LD);
                                if ((reg & (EEPROM_LD_PROGRESS |
                                    EEPROM_LD_START)) == 0)
                                        break;
                                DELAY(1000);
                        }
                        if (i != 0) {
                                CSR_WRITE_4(sc, ALC_EEPROM_LD, reg |
                                    EEPROM_LD_START);
                                for (i = 100; i > 0; i--) {
                                        DELAY(1000);
                                        reg = CSR_READ_4(sc, ALC_EEPROM_LD);
                                        if ((reg & EEPROM_LD_START) == 0)
                                                break;
                                }
                        } else if (bootverbose)
                                device_printf(sc->alc_dev,
                                    "reloading EEPROM/FLASH timed out!\n");
                }
        }

        alc_get_macaddr_par(sc);
}

static void
alc_get_macaddr_par(struct alc_softc *sc)
{
        uint32_t ea[2];

        ea[0] = CSR_READ_4(sc, ALC_PAR0);
        ea[1] = CSR_READ_4(sc, ALC_PAR1);
        sc->alc_eaddr[0] = (ea[1] >> 8) & 0xFF;
        sc->alc_eaddr[1] = (ea[1] >> 0) & 0xFF;
        sc->alc_eaddr[2] = (ea[0] >> 24) & 0xFF;
        sc->alc_eaddr[3] = (ea[0] >> 16) & 0xFF;
        sc->alc_eaddr[4] = (ea[0] >> 8) & 0xFF;
        sc->alc_eaddr[5] = (ea[0] >> 0) & 0xFF;
}

static void
alc_disable_l0s_l1(struct alc_softc *sc)
{
        uint32_t pmcfg;

        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) == 0) {
                /* Another magic from vendor. */
                pmcfg = CSR_READ_4(sc, ALC_PM_CFG);
                pmcfg &= ~(PM_CFG_L1_ENTRY_TIMER_MASK | PM_CFG_CLK_SWH_L1 |
                    PM_CFG_ASPM_L0S_ENB | PM_CFG_ASPM_L1_ENB |
                    PM_CFG_MAC_ASPM_CHK | PM_CFG_SERDES_PD_EX_L1);
                pmcfg |= PM_CFG_SERDES_BUDS_RX_L1_ENB |
                    PM_CFG_SERDES_PLL_L1_ENB | PM_CFG_SERDES_L1_ENB;
                CSR_WRITE_4(sc, ALC_PM_CFG, pmcfg);
        }
}

static void
alc_phy_reset(struct alc_softc *sc)
{

        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0)
                alc_phy_reset_816x(sc);
        else
                alc_phy_reset_813x(sc);
}

static void
alc_phy_reset_813x(struct alc_softc *sc)
{
        uint16_t data;

        /* Reset magic from Linux. */
        CSR_WRITE_2(sc, ALC_GPHY_CFG, GPHY_CFG_SEL_ANA_RESET);
        CSR_READ_2(sc, ALC_GPHY_CFG);
        DELAY(10 * 1000);

        CSR_WRITE_2(sc, ALC_GPHY_CFG, GPHY_CFG_EXT_RESET |
            GPHY_CFG_SEL_ANA_RESET);
        CSR_READ_2(sc, ALC_GPHY_CFG);
        DELAY(10 * 1000);

        /* DSP fixup, Vendor magic. */
        if (sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8152_B) {
                alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
                    ALC_MII_DBG_ADDR, 0x000A);
                data = alc_miibus_readreg(sc->alc_dev, sc->alc_phyaddr,
                    ALC_MII_DBG_DATA);
                alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
                    ALC_MII_DBG_DATA, data & 0xDFFF);
        }
        if (sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8151 ||
            sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8151_V2 ||
            sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8152_B ||
            sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8152_B2) {
                alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
                    ALC_MII_DBG_ADDR, 0x003B);
                data = alc_miibus_readreg(sc->alc_dev, sc->alc_phyaddr,
                    ALC_MII_DBG_DATA);
                alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
                    ALC_MII_DBG_DATA, data & 0xFFF7);
                DELAY(20 * 1000);
        }
        if (sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8151) {
                alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
                    ALC_MII_DBG_ADDR, 0x0029);
                alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
                    ALC_MII_DBG_DATA, 0x929D);
        }
        if (sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8131 ||
            sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8132 ||
            sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8151_V2 ||
            sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8152_B2) {
                alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
                    ALC_MII_DBG_ADDR, 0x0029);
                alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
                    ALC_MII_DBG_DATA, 0xB6DD);
        }

        /* Load DSP codes, vendor magic. */
        data = ANA_LOOP_SEL_10BT | ANA_EN_MASK_TB | ANA_EN_10BT_IDLE |
            ((1 << ANA_INTERVAL_SEL_TIMER_SHIFT) & ANA_INTERVAL_SEL_TIMER_MASK);
        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
            ALC_MII_DBG_ADDR, MII_ANA_CFG18);
        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
            ALC_MII_DBG_DATA, data);

        data = ((2 << ANA_SERDES_CDR_BW_SHIFT) & ANA_SERDES_CDR_BW_MASK) |
            ANA_SERDES_EN_DEEM | ANA_SERDES_SEL_HSP | ANA_SERDES_EN_PLL |
            ANA_SERDES_EN_LCKDT;
        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
            ALC_MII_DBG_ADDR, MII_ANA_CFG5);
        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
            ALC_MII_DBG_DATA, data);

        data = ((44 << ANA_LONG_CABLE_TH_100_SHIFT) &
            ANA_LONG_CABLE_TH_100_MASK) |
            ((33 << ANA_SHORT_CABLE_TH_100_SHIFT) &
            ANA_SHORT_CABLE_TH_100_SHIFT) |
            ANA_BP_BAD_LINK_ACCUM | ANA_BP_SMALL_BW;
        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
            ALC_MII_DBG_ADDR, MII_ANA_CFG54);
        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
            ALC_MII_DBG_DATA, data);

        data = ((11 << ANA_IECHO_ADJ_3_SHIFT) & ANA_IECHO_ADJ_3_MASK) |
            ((11 << ANA_IECHO_ADJ_2_SHIFT) & ANA_IECHO_ADJ_2_MASK) |
            ((8 << ANA_IECHO_ADJ_1_SHIFT) & ANA_IECHO_ADJ_1_MASK) |
            ((8 << ANA_IECHO_ADJ_0_SHIFT) & ANA_IECHO_ADJ_0_MASK);
        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
            ALC_MII_DBG_ADDR, MII_ANA_CFG4);
        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
            ALC_MII_DBG_DATA, data);

        data = ((7 & ANA_MANUL_SWICH_ON_SHIFT) & ANA_MANUL_SWICH_ON_MASK) |
            ANA_RESTART_CAL | ANA_MAN_ENABLE | ANA_SEL_HSP | ANA_EN_HB |
            ANA_OEN_125M;
        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
            ALC_MII_DBG_ADDR, MII_ANA_CFG0);
        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
            ALC_MII_DBG_DATA, data);
        DELAY(1000);

        /* Disable hibernation. */
        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr, ALC_MII_DBG_ADDR,
            0x0029);
        data = alc_miibus_readreg(sc->alc_dev, sc->alc_phyaddr,
            ALC_MII_DBG_DATA);
        data &= ~0x8000;
        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr, ALC_MII_DBG_DATA,
            data);

        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr, ALC_MII_DBG_ADDR,
            0x000B);
        data = alc_miibus_readreg(sc->alc_dev, sc->alc_phyaddr,
            ALC_MII_DBG_DATA);
        data &= ~0x8000;
        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr, ALC_MII_DBG_DATA,
            data);
}

static void
alc_phy_reset_816x(struct alc_softc *sc)
{
        uint32_t val;

        val = CSR_READ_4(sc, ALC_GPHY_CFG);
        val &= ~(GPHY_CFG_EXT_RESET | GPHY_CFG_LED_MODE |
            GPHY_CFG_GATE_25M_ENB | GPHY_CFG_PHY_IDDQ | GPHY_CFG_PHY_PLL_ON |
            GPHY_CFG_PWDOWN_HW | GPHY_CFG_100AB_ENB);
        val |= GPHY_CFG_SEL_ANA_RESET;
#ifdef notyet
        val |= GPHY_CFG_HIB_PULSE | GPHY_CFG_HIB_EN | GPHY_CFG_SEL_ANA_RESET;
#else
        /* Disable PHY hibernation. */
        val &= ~(GPHY_CFG_HIB_PULSE | GPHY_CFG_HIB_EN);
#endif
        CSR_WRITE_4(sc, ALC_GPHY_CFG, val);
        DELAY(10);
        CSR_WRITE_4(sc, ALC_GPHY_CFG, val | GPHY_CFG_EXT_RESET);
        DELAY(800);

        /* Vendor PHY magic. */
#ifdef notyet
        alc_miidbg_writereg(sc, MII_DBG_LEGCYPS, DBG_LEGCYPS_DEFAULT);
        alc_miidbg_writereg(sc, MII_DBG_SYSMODCTL, DBG_SYSMODCTL_DEFAULT);
        alc_miiext_writereg(sc, MII_EXT_PCS, MII_EXT_VDRVBIAS,
            EXT_VDRVBIAS_DEFAULT);
#else
        /* Disable PHY hibernation. */
        alc_miidbg_writereg(sc, MII_DBG_LEGCYPS,
            DBG_LEGCYPS_DEFAULT & ~DBG_LEGCYPS_ENB);
        alc_miidbg_writereg(sc, MII_DBG_HIBNEG,
            DBG_HIBNEG_DEFAULT & ~(DBG_HIBNEG_PSHIB_EN | DBG_HIBNEG_HIB_PULSE));
        alc_miidbg_writereg(sc, MII_DBG_GREENCFG, DBG_GREENCFG_DEFAULT);
#endif

        /* XXX Disable EEE. */
        val = CSR_READ_4(sc, ALC_LPI_CTL);
        val &= ~LPI_CTL_ENB;
        CSR_WRITE_4(sc, ALC_LPI_CTL, val);
        alc_miiext_writereg(sc, MII_EXT_ANEG, MII_EXT_ANEG_LOCAL_EEEADV, 0);

        /* PHY power saving. */
        alc_miidbg_writereg(sc, MII_DBG_TST10BTCFG, DBG_TST10BTCFG_DEFAULT);
        alc_miidbg_writereg(sc, MII_DBG_SRDSYSMOD, DBG_SRDSYSMOD_DEFAULT);
        alc_miidbg_writereg(sc, MII_DBG_TST100BTCFG, DBG_TST100BTCFG_DEFAULT);
        alc_miidbg_writereg(sc, MII_DBG_ANACTL, DBG_ANACTL_DEFAULT);
        val = alc_miidbg_readreg(sc, MII_DBG_GREENCFG2);
        val &= ~DBG_GREENCFG2_GATE_DFSE_EN;
        alc_miidbg_writereg(sc, MII_DBG_GREENCFG2, val);

        /* RTL8139C, 120m issue. */
        alc_miiext_writereg(sc, MII_EXT_ANEG, MII_EXT_ANEG_NLP78,
            ANEG_NLP78_120M_DEFAULT);
        alc_miiext_writereg(sc, MII_EXT_ANEG, MII_EXT_ANEG_S3DIG10,
            ANEG_S3DIG10_DEFAULT);

        if ((sc->alc_flags & ALC_FLAG_LINK_WAR) != 0) {
                /* Turn off half amplitude. */
                val = alc_miiext_readreg(sc, MII_EXT_PCS, MII_EXT_CLDCTL3);
                val |= EXT_CLDCTL3_BP_CABLE1TH_DET_GT;
                alc_miiext_writereg(sc, MII_EXT_PCS, MII_EXT_CLDCTL3, val);
                /* Turn off Green feature. */
                val = alc_miidbg_readreg(sc, MII_DBG_GREENCFG2);
                val |= DBG_GREENCFG2_BP_GREEN;
                alc_miidbg_writereg(sc, MII_DBG_GREENCFG2, val);
                /* Turn off half bias. */
                val = alc_miiext_readreg(sc, MII_EXT_PCS, MII_EXT_CLDCTL5);
                val |= EXT_CLDCTL5_BP_VD_HLFBIAS;
                alc_miiext_writereg(sc, MII_EXT_PCS, MII_EXT_CLDCTL5, val);
        }
}

static void
alc_phy_down(struct alc_softc *sc)
{
        uint32_t gphy;

        switch (sc->alc_ident->deviceid) {
        case DEVICEID_ATHEROS_AR8161:
        case DEVICEID_ATHEROS_E2200:
        case DEVICEID_ATHEROS_E2400:
        case DEVICEID_ATHEROS_E2500:
        case DEVICEID_ATHEROS_AR8162:
        case DEVICEID_ATHEROS_AR8171:
        case DEVICEID_ATHEROS_AR8172:
                gphy = CSR_READ_4(sc, ALC_GPHY_CFG);
                gphy &= ~(GPHY_CFG_EXT_RESET | GPHY_CFG_LED_MODE |
                    GPHY_CFG_100AB_ENB | GPHY_CFG_PHY_PLL_ON);
                gphy |= GPHY_CFG_HIB_EN | GPHY_CFG_HIB_PULSE |
                    GPHY_CFG_SEL_ANA_RESET;
                gphy |= GPHY_CFG_PHY_IDDQ | GPHY_CFG_PWDOWN_HW;
                CSR_WRITE_4(sc, ALC_GPHY_CFG, gphy);
                break;
        case DEVICEID_ATHEROS_AR8151:
        case DEVICEID_ATHEROS_AR8151_V2:
        case DEVICEID_ATHEROS_AR8152_B:
        case DEVICEID_ATHEROS_AR8152_B2:
                /*
                 * GPHY power down caused more problems on AR8151 v2.0.
                 * When driver is reloaded after GPHY power down,
                 * accesses to PHY/MAC registers hung the system. Only
                 * cold boot recovered from it.  I'm not sure whether
                 * AR8151 v1.0 also requires this one though.  I don't
                 * have AR8151 v1.0 controller in hand.
                 * The only option left is to isolate the PHY and
                 * initiates power down the PHY which in turn saves
                 * more power when driver is unloaded.
                 */
                alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
                    MII_BMCR, BMCR_ISO | BMCR_PDOWN);
                break;
        default:
                /* Force PHY down. */
                CSR_WRITE_2(sc, ALC_GPHY_CFG, GPHY_CFG_EXT_RESET |
                    GPHY_CFG_SEL_ANA_RESET | GPHY_CFG_PHY_IDDQ |
                    GPHY_CFG_PWDOWN_HW);
                DELAY(1000);
                break;
        }
}

static void
alc_aspm(struct alc_softc *sc, int init, int media)
{

        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0)
                alc_aspm_816x(sc, init);
        else
                alc_aspm_813x(sc, media);
}

static void
alc_aspm_813x(struct alc_softc *sc, int media)
{
        uint32_t pmcfg;
        uint16_t linkcfg;

        if ((sc->alc_flags & ALC_FLAG_LINK) == 0)
                return;

        pmcfg = CSR_READ_4(sc, ALC_PM_CFG);
        if ((sc->alc_flags & (ALC_FLAG_APS | ALC_FLAG_PCIE)) ==
            (ALC_FLAG_APS | ALC_FLAG_PCIE))
                linkcfg = CSR_READ_2(sc, sc->alc_expcap +
                    PCIER_LINK_CTL);
        else
                linkcfg = 0;
        pmcfg &= ~PM_CFG_SERDES_PD_EX_L1;
        pmcfg &= ~(PM_CFG_L1_ENTRY_TIMER_MASK | PM_CFG_LCKDET_TIMER_MASK);
        pmcfg |= PM_CFG_MAC_ASPM_CHK;
        pmcfg |= (PM_CFG_LCKDET_TIMER_DEFAULT << PM_CFG_LCKDET_TIMER_SHIFT);
        pmcfg &= ~(PM_CFG_ASPM_L1_ENB | PM_CFG_ASPM_L0S_ENB);

        if ((sc->alc_flags & ALC_FLAG_APS) != 0) {
                /* Disable extended sync except AR8152 B v1.0 */
                linkcfg &= ~PCIEM_LINK_CTL_EXTENDED_SYNC;
                if (sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8152_B &&
                    sc->alc_rev == ATHEROS_AR8152_B_V10)
                        linkcfg |= PCIEM_LINK_CTL_EXTENDED_SYNC;
                CSR_WRITE_2(sc, sc->alc_expcap + PCIER_LINK_CTL,
                    linkcfg);
                pmcfg &= ~(PM_CFG_EN_BUFS_RX_L0S | PM_CFG_SA_DLY_ENB |
                    PM_CFG_HOTRST);
                pmcfg |= (PM_CFG_L1_ENTRY_TIMER_DEFAULT <<
                    PM_CFG_L1_ENTRY_TIMER_SHIFT);
                pmcfg &= ~PM_CFG_PM_REQ_TIMER_MASK;
                pmcfg |= (PM_CFG_PM_REQ_TIMER_DEFAULT <<
                    PM_CFG_PM_REQ_TIMER_SHIFT);
                pmcfg |= PM_CFG_SERDES_PD_EX_L1 | PM_CFG_PCIE_RECV;
        }

        if ((sc->alc_flags & ALC_FLAG_LINK) != 0) {
                if ((sc->alc_flags & ALC_FLAG_L0S) != 0)
                        pmcfg |= PM_CFG_ASPM_L0S_ENB;
                if ((sc->alc_flags & ALC_FLAG_L1S) != 0)
                        pmcfg |= PM_CFG_ASPM_L1_ENB;
                if ((sc->alc_flags & ALC_FLAG_APS) != 0) {
                        if (sc->alc_ident->deviceid ==
                            DEVICEID_ATHEROS_AR8152_B)
                                pmcfg &= ~PM_CFG_ASPM_L0S_ENB;
                        pmcfg &= ~(PM_CFG_SERDES_L1_ENB |
                            PM_CFG_SERDES_PLL_L1_ENB |
                            PM_CFG_SERDES_BUDS_RX_L1_ENB);
                        pmcfg |= PM_CFG_CLK_SWH_L1;
                        if (media == IFM_100_TX || media == IFM_1000_T) {
                                pmcfg &= ~PM_CFG_L1_ENTRY_TIMER_MASK;
                                switch (sc->alc_ident->deviceid) {
                                case DEVICEID_ATHEROS_AR8152_B:
                                        pmcfg |= (7 <<
                                            PM_CFG_L1_ENTRY_TIMER_SHIFT);
                                        break;
                                case DEVICEID_ATHEROS_AR8152_B2:
                                case DEVICEID_ATHEROS_AR8151_V2:
                                        pmcfg |= (4 <<
                                            PM_CFG_L1_ENTRY_TIMER_SHIFT);
                                        break;
                                default:
                                        pmcfg |= (15 <<
                                            PM_CFG_L1_ENTRY_TIMER_SHIFT);
                                        break;
                                }
                        }
                } else {
                        pmcfg |= PM_CFG_SERDES_L1_ENB |
                            PM_CFG_SERDES_PLL_L1_ENB |
                            PM_CFG_SERDES_BUDS_RX_L1_ENB;
                        pmcfg &= ~(PM_CFG_CLK_SWH_L1 |
                            PM_CFG_ASPM_L1_ENB | PM_CFG_ASPM_L0S_ENB);
                }
        } else {
                pmcfg &= ~(PM_CFG_SERDES_BUDS_RX_L1_ENB | PM_CFG_SERDES_L1_ENB |
                    PM_CFG_SERDES_PLL_L1_ENB);
                pmcfg |= PM_CFG_CLK_SWH_L1;
                if ((sc->alc_flags & ALC_FLAG_L1S) != 0)
                        pmcfg |= PM_CFG_ASPM_L1_ENB;
        }
        CSR_WRITE_4(sc, ALC_PM_CFG, pmcfg);
}

static void
alc_aspm_816x(struct alc_softc *sc, int init)
{
        uint32_t pmcfg;

        pmcfg = CSR_READ_4(sc, ALC_PM_CFG);
        pmcfg &= ~PM_CFG_L1_ENTRY_TIMER_816X_MASK;
        pmcfg |= PM_CFG_L1_ENTRY_TIMER_816X_DEFAULT;
        pmcfg &= ~PM_CFG_PM_REQ_TIMER_MASK;
        pmcfg |= PM_CFG_PM_REQ_TIMER_816X_DEFAULT;
        pmcfg &= ~PM_CFG_LCKDET_TIMER_MASK;
        pmcfg |= PM_CFG_LCKDET_TIMER_DEFAULT;
        pmcfg |= PM_CFG_SERDES_PD_EX_L1 | PM_CFG_CLK_SWH_L1 | PM_CFG_PCIE_RECV;
        pmcfg &= ~(PM_CFG_RX_L1_AFTER_L0S | PM_CFG_TX_L1_AFTER_L0S |
            PM_CFG_ASPM_L1_ENB | PM_CFG_ASPM_L0S_ENB |
            PM_CFG_SERDES_L1_ENB | PM_CFG_SERDES_PLL_L1_ENB |
            PM_CFG_SERDES_BUDS_RX_L1_ENB | PM_CFG_SA_DLY_ENB |
            PM_CFG_MAC_ASPM_CHK | PM_CFG_HOTRST);
        if (AR816X_REV(sc->alc_rev) <= AR816X_REV_A1 &&
            (sc->alc_rev & 0x01) != 0)
                pmcfg |= PM_CFG_SERDES_L1_ENB | PM_CFG_SERDES_PLL_L1_ENB;
        if ((sc->alc_flags & ALC_FLAG_LINK) != 0) {
                /* Link up, enable both L0s, L1s. */
                pmcfg |= PM_CFG_ASPM_L0S_ENB | PM_CFG_ASPM_L1_ENB |
                    PM_CFG_MAC_ASPM_CHK;
        } else {
                if (init != 0)
                        pmcfg |= PM_CFG_ASPM_L0S_ENB | PM_CFG_ASPM_L1_ENB |
                            PM_CFG_MAC_ASPM_CHK;
                else if ((if_getdrvflags(sc->alc_ifp) & IFF_DRV_RUNNING) != 0)
                        pmcfg |= PM_CFG_ASPM_L1_ENB | PM_CFG_MAC_ASPM_CHK;
        }
        CSR_WRITE_4(sc, ALC_PM_CFG, pmcfg);
}

static void
alc_init_pcie(struct alc_softc *sc)
{
        const char *aspm_state[] = { "L0s/L1", "L0s", "L1", "L0s/L1" };
        uint32_t cap, ctl, val;
        int state;

        /* Clear data link and flow-control protocol error. */
        val = CSR_READ_4(sc, ALC_PEX_UNC_ERR_SEV);
        val &= ~(PEX_UNC_ERR_SEV_DLP | PEX_UNC_ERR_SEV_FCP);
        CSR_WRITE_4(sc, ALC_PEX_UNC_ERR_SEV, val);

        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) == 0) {
                CSR_WRITE_4(sc, ALC_LTSSM_ID_CFG,
                    CSR_READ_4(sc, ALC_LTSSM_ID_CFG) & ~LTSSM_ID_WRO_ENB);
                CSR_WRITE_4(sc, ALC_PCIE_PHYMISC,
                    CSR_READ_4(sc, ALC_PCIE_PHYMISC) |
                    PCIE_PHYMISC_FORCE_RCV_DET);
                if (sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8152_B &&
                    sc->alc_rev == ATHEROS_AR8152_B_V10) {
                        val = CSR_READ_4(sc, ALC_PCIE_PHYMISC2);
                        val &= ~(PCIE_PHYMISC2_SERDES_CDR_MASK |
                            PCIE_PHYMISC2_SERDES_TH_MASK);
                        val |= 3 << PCIE_PHYMISC2_SERDES_CDR_SHIFT;
                        val |= 3 << PCIE_PHYMISC2_SERDES_TH_SHIFT;
                        CSR_WRITE_4(sc, ALC_PCIE_PHYMISC2, val);
                }
                /* Disable ASPM L0S and L1. */
                cap = CSR_READ_2(sc, sc->alc_expcap + PCIER_LINK_CAP);
                if ((cap & PCIEM_LINK_CAP_ASPM) != 0) {
                        ctl = CSR_READ_2(sc, sc->alc_expcap + PCIER_LINK_CTL);
                        if ((ctl & PCIEM_LINK_CTL_RCB) != 0)
                                sc->alc_rcb = DMA_CFG_RCB_128;
                        if (bootverbose)
                                device_printf(sc->alc_dev, "RCB %u bytes\n",
                                    sc->alc_rcb == DMA_CFG_RCB_64 ? 64 : 128);
                        state = ctl & PCIEM_LINK_CTL_ASPMC;
                        if (state & PCIEM_LINK_CTL_ASPMC_L0S)
                                sc->alc_flags |= ALC_FLAG_L0S;
                        if (state & PCIEM_LINK_CTL_ASPMC_L1)
                                sc->alc_flags |= ALC_FLAG_L1S;
                        if (bootverbose)
                                device_printf(sc->alc_dev, "ASPM %s %s\n",
                                    aspm_state[state],
                                    state == 0 ? "disabled" : "enabled");
                        alc_disable_l0s_l1(sc);
                } else {
                        if (bootverbose)
                                device_printf(sc->alc_dev,
                                    "no ASPM support\n");
                }
        } else {
                val = CSR_READ_4(sc, ALC_PDLL_TRNS1);
                val &= ~PDLL_TRNS1_D3PLLOFF_ENB;
                CSR_WRITE_4(sc, ALC_PDLL_TRNS1, val);
                val = CSR_READ_4(sc, ALC_MASTER_CFG);
                if (AR816X_REV(sc->alc_rev) <= AR816X_REV_A1 &&
                    (sc->alc_rev & 0x01) != 0) {
                        if ((val & MASTER_WAKEN_25M) == 0 ||
                            (val & MASTER_CLK_SEL_DIS) == 0) {
                                val |= MASTER_WAKEN_25M | MASTER_CLK_SEL_DIS;
                                CSR_WRITE_4(sc, ALC_MASTER_CFG, val);
                        }
                } else {
                        if ((val & MASTER_WAKEN_25M) == 0 ||
                            (val & MASTER_CLK_SEL_DIS) != 0) {
                                val |= MASTER_WAKEN_25M;
                                val &= ~MASTER_CLK_SEL_DIS;
                                CSR_WRITE_4(sc, ALC_MASTER_CFG, val);
                        }
                }
        }
        alc_aspm(sc, 1, IFM_UNKNOWN);
}

static void
alc_config_msi(struct alc_softc *sc)
{
        uint32_t ctl, mod;

        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0) {
                /*
                 * It seems interrupt moderation is controlled by
                 * ALC_MSI_RETRANS_TIMER register if MSI/MSIX is active.
                 * Driver uses RX interrupt moderation parameter to
                 * program ALC_MSI_RETRANS_TIMER register.
                 */
                ctl = CSR_READ_4(sc, ALC_MSI_RETRANS_TIMER);
                ctl &= ~MSI_RETRANS_TIMER_MASK;
                ctl &= ~MSI_RETRANS_MASK_SEL_LINE;
                mod = ALC_USECS(sc->alc_int_rx_mod);
                if (mod == 0)
                        mod = 1;
                ctl |= mod;
                if ((sc->alc_flags & ALC_FLAG_MSIX) != 0)
                        CSR_WRITE_4(sc, ALC_MSI_RETRANS_TIMER, ctl |
                            MSI_RETRANS_MASK_SEL_STD);
                else if ((sc->alc_flags & ALC_FLAG_MSI) != 0)
                        CSR_WRITE_4(sc, ALC_MSI_RETRANS_TIMER, ctl |
                            MSI_RETRANS_MASK_SEL_LINE);
                else
                        CSR_WRITE_4(sc, ALC_MSI_RETRANS_TIMER, 0);
        }
}

static int
alc_attach(device_t dev)
{
        struct alc_softc *sc;
        if_t ifp;
        int base, error, i, msic, msixc;
        uint16_t burst;

        error = 0;
        sc = device_get_softc(dev);
        sc->alc_dev = dev;
        sc->alc_rev = pci_get_revid(dev);

        mtx_init(&sc->alc_mtx, device_get_nameunit(dev), MTX_NETWORK_LOCK,
            MTX_DEF);
        callout_init_mtx(&sc->alc_tick_ch, &sc->alc_mtx, 0);
        NET_TASK_INIT(&sc->alc_int_task, 0, alc_int_task, sc);
        sc->alc_ident = alc_find_ident(dev);

        /* Map the device. */
        pci_enable_busmaster(dev);
        sc->alc_res_spec = alc_res_spec_mem;
        sc->alc_irq_spec = alc_irq_spec_legacy;
        error = bus_alloc_resources(dev, sc->alc_res_spec, sc->alc_res);
        if (error != 0) {
                device_printf(dev, "cannot allocate memory resources.\n");
                goto fail;
        }

        /* Set PHY address. */
        sc->alc_phyaddr = ALC_PHY_ADDR;

        /*
         * One odd thing is AR8132 uses the same PHY hardware(F1
         * gigabit PHY) of AR8131. So atphy(4) of AR8132 reports
         * the PHY supports 1000Mbps but that's not true. The PHY
         * used in AR8132 can't establish gigabit link even if it
         * shows the same PHY model/revision number of AR8131.
         */
        switch (sc->alc_ident->deviceid) {
        case DEVICEID_ATHEROS_E2200:
        case DEVICEID_ATHEROS_E2400:
        case DEVICEID_ATHEROS_E2500:
                sc->alc_flags |= ALC_FLAG_E2X00;

                /*
                 * Disable MSI-X by default on Killer devices, since this is
                 * reported by several users to not work well.
                 */
                if (msix_disable == 2)
                        msix_disable = 1;

                /* FALLTHROUGH */
        case DEVICEID_ATHEROS_AR8161:
                if (pci_get_subvendor(dev) == VENDORID_ATHEROS &&
                    pci_get_subdevice(dev) == 0x0091 && sc->alc_rev == 0)
                        sc->alc_flags |= ALC_FLAG_LINK_WAR;
                /* FALLTHROUGH */
        case DEVICEID_ATHEROS_AR8171:
                sc->alc_flags |= ALC_FLAG_AR816X_FAMILY;
                break;
        case DEVICEID_ATHEROS_AR8162:
        case DEVICEID_ATHEROS_AR8172:
                sc->alc_flags |= ALC_FLAG_FASTETHER | ALC_FLAG_AR816X_FAMILY;
                break;
        case DEVICEID_ATHEROS_AR8152_B:
        case DEVICEID_ATHEROS_AR8152_B2:
                sc->alc_flags |= ALC_FLAG_APS;
                /* FALLTHROUGH */
        case DEVICEID_ATHEROS_AR8132:
                sc->alc_flags |= ALC_FLAG_FASTETHER;
                break;
        case DEVICEID_ATHEROS_AR8151:
        case DEVICEID_ATHEROS_AR8151_V2:
                sc->alc_flags |= ALC_FLAG_APS;
                if (CSR_READ_4(sc, ALC_MT_MAGIC) == MT_MAGIC)
                        sc->alc_flags |= ALC_FLAG_MT;
                /* FALLTHROUGH */
        default:
                break;
        }

        /*
         * The default value of msix_disable is 2, which means auto-detect.  If
         * we didn't auto-detect it, default to enabling it.
         */
        if (msix_disable == 2)
                msix_disable = 0;

        sc->alc_flags |= ALC_FLAG_JUMBO;

        /*
         * It seems that AR813x/AR815x has silicon bug for SMB. In
         * addition, Atheros said that enabling SMB wouldn't improve
         * performance. However I think it's bad to access lots of
         * registers to extract MAC statistics.
         */
        sc->alc_flags |= ALC_FLAG_SMB_BUG;
        /*
         * Don't use Tx CMB. It is known to have silicon bug.
         */
        sc->alc_flags |= ALC_FLAG_CMB_BUG;
        sc->alc_chip_rev = CSR_READ_4(sc, ALC_MASTER_CFG) >>
            MASTER_CHIP_REV_SHIFT;
        if (bootverbose) {
                device_printf(dev, "PCI device revision : 0x%04x\n",
                    sc->alc_rev);
                device_printf(dev, "Chip id/revision : 0x%04x\n",
                    sc->alc_chip_rev);
                if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0)
                        device_printf(dev, "AR816x revision : 0x%x\n",
                            AR816X_REV(sc->alc_rev));
        }
        device_printf(dev, "%u Tx FIFO, %u Rx FIFO\n",
            CSR_READ_4(sc, ALC_SRAM_TX_FIFO_LEN) * 8,
            CSR_READ_4(sc, ALC_SRAM_RX_FIFO_LEN) * 8);

        /* Initialize DMA parameters. */
        sc->alc_dma_rd_burst = 0;
        sc->alc_dma_wr_burst = 0;
        sc->alc_rcb = DMA_CFG_RCB_64;
        if (pci_find_cap(dev, PCIY_EXPRESS, &base) == 0) {
                sc->alc_flags |= ALC_FLAG_PCIE;
                sc->alc_expcap = base;
                burst = CSR_READ_2(sc, base + PCIER_DEVICE_CTL);
                sc->alc_dma_rd_burst =
                    (burst & PCIEM_CTL_MAX_READ_REQUEST) >> 12;
                sc->alc_dma_wr_burst = (burst & PCIEM_CTL_MAX_PAYLOAD) >> 5;
                if (bootverbose) {
                        device_printf(dev, "Read request size : %u bytes.\n",
                            alc_dma_burst[sc->alc_dma_rd_burst]);
                        device_printf(dev, "TLP payload size : %u bytes.\n",
                            alc_dma_burst[sc->alc_dma_wr_burst]);
                }
                if (alc_dma_burst[sc->alc_dma_rd_burst] > 1024)
                        sc->alc_dma_rd_burst = 3;
                if (alc_dma_burst[sc->alc_dma_wr_burst] > 1024)
                        sc->alc_dma_wr_burst = 3;
                /*
                 * Force maximum payload size to 128 bytes for
                 * E2200/E2400/E2500/AR8162/AR8171/AR8172.
                 * Otherwise it triggers DMA write error.
                 */
                if ((sc->alc_flags &
                    (ALC_FLAG_E2X00 | ALC_FLAG_AR816X_FAMILY)) != 0)
                        sc->alc_dma_wr_burst = 0;
                alc_init_pcie(sc);
        }

        /* Reset PHY. */
        alc_phy_reset(sc);

        /* Reset the ethernet controller. */
        alc_stop_mac(sc);
        alc_reset(sc);

        /* Allocate IRQ resources. */
        msixc = pci_msix_count(dev);
        msic = pci_msi_count(dev);
        if (bootverbose) {
                device_printf(dev, "MSIX count : %d\n", msixc);
                device_printf(dev, "MSI count : %d\n", msic);
        }
        if (msixc > 1)
                msixc = 1;
        if (msic > 1)
                msic = 1;
        /*
         * Prefer MSIX over MSI.
         * AR816x controller has a silicon bug that MSI interrupt
         * does not assert if PCIM_CMD_INTxDIS bit of command
         * register is set.  pci(4) was taught to handle that case.
         */
        if (msix_disable == 0 || msi_disable == 0) {
                if (msix_disable == 0 && msixc > 0 &&
                    pci_alloc_msix(dev, &msixc) == 0) {
                        if (msic == 1) {
                                device_printf(dev,
                                    "Using %d MSIX message(s).\n", msixc);
                                sc->alc_flags |= ALC_FLAG_MSIX;
                                sc->alc_irq_spec = alc_irq_spec_msix;
                        } else
                                pci_release_msi(dev);
                }
                if (msi_disable == 0 && (sc->alc_flags & ALC_FLAG_MSIX) == 0 &&
                    msic > 0 && pci_alloc_msi(dev, &msic) == 0) {
                        if (msic == 1) {
                                device_printf(dev,
                                    "Using %d MSI message(s).\n", msic);
                                sc->alc_flags |= ALC_FLAG_MSI;
                                sc->alc_irq_spec = alc_irq_spec_msi;
                        } else
                                pci_release_msi(dev);
                }
        }

        error = bus_alloc_resources(dev, sc->alc_irq_spec, sc->alc_irq);
        if (error != 0) {
                device_printf(dev, "cannot allocate IRQ resources.\n");
                goto fail;
        }

        /* Create device sysctl node. */
        alc_sysctl_node(sc);

        if ((error = alc_dma_alloc(sc)) != 0)
                goto fail;

        /* Load station address. */
        alc_get_macaddr(sc);

        ifp = sc->alc_ifp = if_alloc(IFT_ETHER);
        if (ifp == NULL) {
                device_printf(dev, "cannot allocate ifnet structure.\n");
                error = ENXIO;
                goto fail;
        }

        if_setsoftc(ifp, sc);
        if_initname(ifp, device_get_name(dev), device_get_unit(dev));
        if_setflags(ifp, IFF_BROADCAST | IFF_SIMPLEX | IFF_MULTICAST);
        if_setioctlfn(ifp, alc_ioctl);
        if_setstartfn(ifp, alc_start);
        if_setinitfn(ifp, alc_init);
        if_setsendqlen(ifp, ALC_TX_RING_CNT - 1);
        if_setsendqready(ifp);
        if_setcapabilities(ifp, IFCAP_TXCSUM | IFCAP_TSO4);
        if_sethwassist(ifp, ALC_CSUM_FEATURES | CSUM_TSO);
        if (pci_find_cap(dev, PCIY_PMG, &base) == 0) {
                if_setcapabilitiesbit(ifp, IFCAP_WOL_MAGIC | IFCAP_WOL_MCAST, 0);
                sc->alc_flags |= ALC_FLAG_PM;
                sc->alc_pmcap = base;
        }
        if_setcapenable(ifp, if_getcapabilities(ifp));

        /* Set up MII bus. */
        error = mii_attach(dev, &sc->alc_miibus, ifp, alc_mediachange,
            alc_mediastatus, BMSR_DEFCAPMASK, sc->alc_phyaddr, MII_OFFSET_ANY,
            MIIF_DOPAUSE);
        if (error != 0) {
                device_printf(dev, "attaching PHYs failed\n");
                goto fail;
        }

        ether_ifattach(ifp, sc->alc_eaddr);

        /* VLAN capability setup. */
        if_setcapabilitiesbit(ifp, IFCAP_VLAN_MTU | IFCAP_VLAN_HWTAGGING |
            IFCAP_VLAN_HWCSUM | IFCAP_VLAN_HWTSO, 0);
        if_setcapenable(ifp, if_getcapabilities(ifp));
        /*
         * XXX
         * It seems enabling Tx checksum offloading makes more trouble.
         * Sometimes the controller does not receive any frames when
         * Tx checksum offloading is enabled. I'm not sure whether this
         * is a bug in Tx checksum offloading logic or I got broken
         * sample boards. To safety, don't enable Tx checksum offloading
         * by default but give chance to users to toggle it if they know
         * their controllers work without problems.
         * Fortunately, Tx checksum offloading for AR816x family
         * seems to work.
         */
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) == 0) {
                if_setcapenablebit(ifp, 0, IFCAP_TXCSUM);
                if_sethwassistbits(ifp, 0, ALC_CSUM_FEATURES);
        }

        /* Tell the upper layer(s) we support long frames. */
        if_setifheaderlen(ifp, sizeof(struct ether_vlan_header));

        /* Create local taskq. */
        sc->alc_tq = taskqueue_create_fast("alc_taskq", M_WAITOK,
            taskqueue_thread_enqueue, &sc->alc_tq);
        if (sc->alc_tq == NULL) {
                device_printf(dev, "could not create taskqueue.\n");
                ether_ifdetach(ifp);
                error = ENXIO;
                goto fail;
        }
        taskqueue_start_threads(&sc->alc_tq, 1, PI_NET, "%s taskq",
            device_get_nameunit(sc->alc_dev));

        alc_config_msi(sc);
        if ((sc->alc_flags & ALC_FLAG_MSIX) != 0)
                msic = ALC_MSIX_MESSAGES;
        else if ((sc->alc_flags & ALC_FLAG_MSI) != 0)
                msic = ALC_MSI_MESSAGES;
        else
                msic = 1;
        for (i = 0; i < msic; i++) {
                error = bus_setup_intr(dev, sc->alc_irq[i],
                    INTR_TYPE_NET | INTR_MPSAFE, alc_intr, NULL, sc,
                    &sc->alc_intrhand[i]);
                if (error != 0)
                        break;
        }
        if (error != 0) {
                device_printf(dev, "could not set up interrupt handler.\n");
                taskqueue_free(sc->alc_tq);
                sc->alc_tq = NULL;
                ether_ifdetach(ifp);
                goto fail;
        }

        /* Attach driver debugnet methods. */
        DEBUGNET_SET(ifp, alc);

fail:
        if (error != 0)
                alc_detach(dev);

        return (error);
}

static int
alc_detach(device_t dev)
{
        struct alc_softc *sc;
        if_t ifp;
        int i, msic;

        sc = device_get_softc(dev);

        ifp = sc->alc_ifp;
        if (device_is_attached(dev)) {
                ether_ifdetach(ifp);
                ALC_LOCK(sc);
                alc_stop(sc);
                ALC_UNLOCK(sc);
                callout_drain(&sc->alc_tick_ch);
                taskqueue_drain(sc->alc_tq, &sc->alc_int_task);
        }

        if (sc->alc_tq != NULL) {
                taskqueue_drain(sc->alc_tq, &sc->alc_int_task);
                taskqueue_free(sc->alc_tq);
                sc->alc_tq = NULL;
        }

        if (sc->alc_miibus != NULL) {
                device_delete_child(dev, sc->alc_miibus);
                sc->alc_miibus = NULL;
        }
        bus_generic_detach(dev);
        alc_dma_free(sc);

        if (ifp != NULL) {
                if_free(ifp);
                sc->alc_ifp = NULL;
        }

        if ((sc->alc_flags & ALC_FLAG_MSIX) != 0)
                msic = ALC_MSIX_MESSAGES;
        else if ((sc->alc_flags & ALC_FLAG_MSI) != 0)
                msic = ALC_MSI_MESSAGES;
        else
                msic = 1;
        for (i = 0; i < msic; i++) {
                if (sc->alc_intrhand[i] != NULL) {
                        bus_teardown_intr(dev, sc->alc_irq[i],
                            sc->alc_intrhand[i]);
                        sc->alc_intrhand[i] = NULL;
                }
        }
        if (sc->alc_res[0] != NULL)
                alc_phy_down(sc);
        bus_release_resources(dev, sc->alc_irq_spec, sc->alc_irq);
        if ((sc->alc_flags & (ALC_FLAG_MSI | ALC_FLAG_MSIX)) != 0)
                pci_release_msi(dev);
        bus_release_resources(dev, sc->alc_res_spec, sc->alc_res);
        mtx_destroy(&sc->alc_mtx);

        return (0);
}

#define ALC_SYSCTL_STAT_ADD32(c, h, n, p, d)    \
            SYSCTL_ADD_UINT(c, h, OID_AUTO, n, CTLFLAG_RD, p, 0, d)
#define ALC_SYSCTL_STAT_ADD64(c, h, n, p, d)    \
            SYSCTL_ADD_UQUAD(c, h, OID_AUTO, n, CTLFLAG_RD, p, d)

static void
alc_sysctl_node(struct alc_softc *sc)
{
        struct sysctl_ctx_list *ctx;
        struct sysctl_oid_list *child, *parent;
        struct sysctl_oid *tree;
        struct alc_hw_stats *stats;
        int error;

        stats = &sc->alc_stats;
        ctx = device_get_sysctl_ctx(sc->alc_dev);
        child = SYSCTL_CHILDREN(device_get_sysctl_tree(sc->alc_dev));

        SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "int_rx_mod",
            CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &sc->alc_int_rx_mod,
            0, sysctl_hw_alc_int_mod, "I", "alc Rx interrupt moderation");
        SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "int_tx_mod",
            CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT, &sc->alc_int_tx_mod,
            0, sysctl_hw_alc_int_mod, "I", "alc Tx interrupt moderation");
        /* Pull in device tunables. */
        sc->alc_int_rx_mod = ALC_IM_RX_TIMER_DEFAULT;
        error = resource_int_value(device_get_name(sc->alc_dev),
            device_get_unit(sc->alc_dev), "int_rx_mod", &sc->alc_int_rx_mod);
        if (error == 0) {
                if (sc->alc_int_rx_mod < ALC_IM_TIMER_MIN ||
                    sc->alc_int_rx_mod > ALC_IM_TIMER_MAX) {
                        device_printf(sc->alc_dev, "int_rx_mod value out of "
                            "range; using default: %d\n",
                            ALC_IM_RX_TIMER_DEFAULT);
                        sc->alc_int_rx_mod = ALC_IM_RX_TIMER_DEFAULT;
                }
        }
        sc->alc_int_tx_mod = ALC_IM_TX_TIMER_DEFAULT;
        error = resource_int_value(device_get_name(sc->alc_dev),
            device_get_unit(sc->alc_dev), "int_tx_mod", &sc->alc_int_tx_mod);
        if (error == 0) {
                if (sc->alc_int_tx_mod < ALC_IM_TIMER_MIN ||
                    sc->alc_int_tx_mod > ALC_IM_TIMER_MAX) {
                        device_printf(sc->alc_dev, "int_tx_mod value out of "
                            "range; using default: %d\n",
                            ALC_IM_TX_TIMER_DEFAULT);
                        sc->alc_int_tx_mod = ALC_IM_TX_TIMER_DEFAULT;
                }
        }
        SYSCTL_ADD_PROC(ctx, child, OID_AUTO, "process_limit",
            CTLTYPE_INT | CTLFLAG_RW | CTLFLAG_NEEDGIANT,
            &sc->alc_process_limit, 0, sysctl_hw_alc_proc_limit, "I",
            "max number of Rx events to process");
        /* Pull in device tunables. */
        sc->alc_process_limit = ALC_PROC_DEFAULT;
        error = resource_int_value(device_get_name(sc->alc_dev),
            device_get_unit(sc->alc_dev), "process_limit",
            &sc->alc_process_limit);
        if (error == 0) {
                if (sc->alc_process_limit < ALC_PROC_MIN ||
                    sc->alc_process_limit > ALC_PROC_MAX) {
                        device_printf(sc->alc_dev,
                            "process_limit value out of range; "
                            "using default: %d\n", ALC_PROC_DEFAULT);
                        sc->alc_process_limit = ALC_PROC_DEFAULT;
                }
        }

        tree = SYSCTL_ADD_NODE(ctx, child, OID_AUTO, "stats",
            CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "ALC statistics");
        parent = SYSCTL_CHILDREN(tree);

        /* Rx statistics. */
        tree = SYSCTL_ADD_NODE(ctx, parent, OID_AUTO, "rx",
            CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "Rx MAC statistics");
        child = SYSCTL_CHILDREN(tree);
        ALC_SYSCTL_STAT_ADD32(ctx, child, "good_frames",
            &stats->rx_frames, "Good frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "good_bcast_frames",
            &stats->rx_bcast_frames, "Good broadcast frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "good_mcast_frames",
            &stats->rx_mcast_frames, "Good multicast frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "pause_frames",
            &stats->rx_pause_frames, "Pause control frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "control_frames",
            &stats->rx_control_frames, "Control frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "crc_errs",
            &stats->rx_crcerrs, "CRC errors");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "len_errs",
            &stats->rx_lenerrs, "Frames with length mismatched");
        ALC_SYSCTL_STAT_ADD64(ctx, child, "good_octets",
            &stats->rx_bytes, "Good octets");
        ALC_SYSCTL_STAT_ADD64(ctx, child, "good_bcast_octets",
            &stats->rx_bcast_bytes, "Good broadcast octets");
        ALC_SYSCTL_STAT_ADD64(ctx, child, "good_mcast_octets",
            &stats->rx_mcast_bytes, "Good multicast octets");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "runts",
            &stats->rx_runts, "Too short frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "fragments",
            &stats->rx_fragments, "Fragmented frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "frames_64",
            &stats->rx_pkts_64, "64 bytes frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "frames_65_127",
            &stats->rx_pkts_65_127, "65 to 127 bytes frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "frames_128_255",
            &stats->rx_pkts_128_255, "128 to 255 bytes frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "frames_256_511",
            &stats->rx_pkts_256_511, "256 to 511 bytes frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "frames_512_1023",
            &stats->rx_pkts_512_1023, "512 to 1023 bytes frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "frames_1024_1518",
            &stats->rx_pkts_1024_1518, "1024 to 1518 bytes frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "frames_1519_max",
            &stats->rx_pkts_1519_max, "1519 to max frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "trunc_errs",
            &stats->rx_pkts_truncated, "Truncated frames due to MTU size");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "fifo_oflows",
            &stats->rx_fifo_oflows, "FIFO overflows");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "rrs_errs",
            &stats->rx_rrs_errs, "Return status write-back errors");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "align_errs",
            &stats->rx_alignerrs, "Alignment errors");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "filtered",
            &stats->rx_pkts_filtered,
            "Frames dropped due to address filtering");

        /* Tx statistics. */
        tree = SYSCTL_ADD_NODE(ctx, parent, OID_AUTO, "tx",
            CTLFLAG_RD | CTLFLAG_MPSAFE, NULL, "Tx MAC statistics");
        child = SYSCTL_CHILDREN(tree);
        ALC_SYSCTL_STAT_ADD32(ctx, child, "good_frames",
            &stats->tx_frames, "Good frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "good_bcast_frames",
            &stats->tx_bcast_frames, "Good broadcast frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "good_mcast_frames",
            &stats->tx_mcast_frames, "Good multicast frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "pause_frames",
            &stats->tx_pause_frames, "Pause control frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "control_frames",
            &stats->tx_control_frames, "Control frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "excess_defers",
            &stats->tx_excess_defer, "Frames with excessive derferrals");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "defers",
            &stats->tx_excess_defer, "Frames with derferrals");
        ALC_SYSCTL_STAT_ADD64(ctx, child, "good_octets",
            &stats->tx_bytes, "Good octets");
        ALC_SYSCTL_STAT_ADD64(ctx, child, "good_bcast_octets",
            &stats->tx_bcast_bytes, "Good broadcast octets");
        ALC_SYSCTL_STAT_ADD64(ctx, child, "good_mcast_octets",
            &stats->tx_mcast_bytes, "Good multicast octets");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "frames_64",
            &stats->tx_pkts_64, "64 bytes frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "frames_65_127",
            &stats->tx_pkts_65_127, "65 to 127 bytes frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "frames_128_255",
            &stats->tx_pkts_128_255, "128 to 255 bytes frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "frames_256_511",
            &stats->tx_pkts_256_511, "256 to 511 bytes frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "frames_512_1023",
            &stats->tx_pkts_512_1023, "512 to 1023 bytes frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "frames_1024_1518",
            &stats->tx_pkts_1024_1518, "1024 to 1518 bytes frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "frames_1519_max",
            &stats->tx_pkts_1519_max, "1519 to max frames");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "single_colls",
            &stats->tx_single_colls, "Single collisions");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "multi_colls",
            &stats->tx_multi_colls, "Multiple collisions");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "late_colls",
            &stats->tx_late_colls, "Late collisions");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "excess_colls",
            &stats->tx_excess_colls, "Excessive collisions");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "underruns",
            &stats->tx_underrun, "FIFO underruns");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "desc_underruns",
            &stats->tx_desc_underrun, "Descriptor write-back errors");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "len_errs",
            &stats->tx_lenerrs, "Frames with length mismatched");
        ALC_SYSCTL_STAT_ADD32(ctx, child, "trunc_errs",
            &stats->tx_pkts_truncated, "Truncated frames due to MTU size");
}

#undef ALC_SYSCTL_STAT_ADD32
#undef ALC_SYSCTL_STAT_ADD64

struct alc_dmamap_arg {
        bus_addr_t      alc_busaddr;
};

static void
alc_dmamap_cb(void *arg, bus_dma_segment_t *segs, int nsegs, int error)
{
        struct alc_dmamap_arg *ctx;

        if (error != 0)
                return;

        KASSERT(nsegs == 1, ("%s: %d segments returned!", __func__, nsegs));

        ctx = (struct alc_dmamap_arg *)arg;
        ctx->alc_busaddr = segs[0].ds_addr;
}

/*
 * Normal and high Tx descriptors shares single Tx high address.
 * Four Rx descriptor/return rings and CMB shares the same Rx
 * high address.
 */
static int
alc_check_boundary(struct alc_softc *sc)
{
        bus_addr_t cmb_end, rx_ring_end, rr_ring_end, tx_ring_end;

        rx_ring_end = sc->alc_rdata.alc_rx_ring_paddr + ALC_RX_RING_SZ;
        rr_ring_end = sc->alc_rdata.alc_rr_ring_paddr + ALC_RR_RING_SZ;
        cmb_end = sc->alc_rdata.alc_cmb_paddr + ALC_CMB_SZ;
        tx_ring_end = sc->alc_rdata.alc_tx_ring_paddr + ALC_TX_RING_SZ;

        /* 4GB boundary crossing is not allowed. */
        if ((ALC_ADDR_HI(rx_ring_end) !=
            ALC_ADDR_HI(sc->alc_rdata.alc_rx_ring_paddr)) ||
            (ALC_ADDR_HI(rr_ring_end) !=
            ALC_ADDR_HI(sc->alc_rdata.alc_rr_ring_paddr)) ||
            (ALC_ADDR_HI(cmb_end) !=
            ALC_ADDR_HI(sc->alc_rdata.alc_cmb_paddr)) ||
            (ALC_ADDR_HI(tx_ring_end) !=
            ALC_ADDR_HI(sc->alc_rdata.alc_tx_ring_paddr)))
                return (EFBIG);
        /*
         * Make sure Rx return descriptor/Rx descriptor/CMB use
         * the same high address.
         */
        if ((ALC_ADDR_HI(rx_ring_end) != ALC_ADDR_HI(rr_ring_end)) ||
            (ALC_ADDR_HI(rx_ring_end) != ALC_ADDR_HI(cmb_end)))
                return (EFBIG);

        return (0);
}

static int
alc_dma_alloc(struct alc_softc *sc)
{
        struct alc_txdesc *txd;
        struct alc_rxdesc *rxd;
        bus_addr_t lowaddr;
        struct alc_dmamap_arg ctx;
        int error, i;

        lowaddr = BUS_SPACE_MAXADDR;
        if (sc->alc_flags & ALC_FLAG_MT)
                lowaddr = BUS_SPACE_MAXSIZE_32BIT;
again:
        /* Create parent DMA tag. */
        error = bus_dma_tag_create(
            bus_get_dma_tag(sc->alc_dev), /* parent */
            1, 0,                       /* alignment, boundary */
            lowaddr,                    /* lowaddr */
            BUS_SPACE_MAXADDR,          /* highaddr */
            NULL, NULL,                 /* filter, filterarg */
            BUS_SPACE_MAXSIZE_32BIT,    /* maxsize */
            0,                          /* nsegments */
            BUS_SPACE_MAXSIZE_32BIT,    /* maxsegsize */
            0,                          /* flags */
            NULL, NULL,                 /* lockfunc, lockarg */
            &sc->alc_cdata.alc_parent_tag);
        if (error != 0) {
                device_printf(sc->alc_dev,
                    "could not create parent DMA tag.\n");
                goto fail;
        }

        /* Create DMA tag for Tx descriptor ring. */
        error = bus_dma_tag_create(
            sc->alc_cdata.alc_parent_tag, /* parent */
            ALC_TX_RING_ALIGN, 0,       /* alignment, boundary */
            BUS_SPACE_MAXADDR,          /* lowaddr */
            BUS_SPACE_MAXADDR,          /* highaddr */
            NULL, NULL,                 /* filter, filterarg */
            ALC_TX_RING_SZ,             /* maxsize */
            1,                          /* nsegments */
            ALC_TX_RING_SZ,             /* maxsegsize */
            0,                          /* flags */
            NULL, NULL,                 /* lockfunc, lockarg */
            &sc->alc_cdata.alc_tx_ring_tag);
        if (error != 0) {
                device_printf(sc->alc_dev,
                    "could not create Tx ring DMA tag.\n");
                goto fail;
        }

        /* Create DMA tag for Rx free descriptor ring. */
        error = bus_dma_tag_create(
            sc->alc_cdata.alc_parent_tag, /* parent */
            ALC_RX_RING_ALIGN, 0,       /* alignment, boundary */
            BUS_SPACE_MAXADDR,          /* lowaddr */
            BUS_SPACE_MAXADDR,          /* highaddr */
            NULL, NULL,                 /* filter, filterarg */
            ALC_RX_RING_SZ,             /* maxsize */
            1,                          /* nsegments */
            ALC_RX_RING_SZ,             /* maxsegsize */
            0,                          /* flags */
            NULL, NULL,                 /* lockfunc, lockarg */
            &sc->alc_cdata.alc_rx_ring_tag);
        if (error != 0) {
                device_printf(sc->alc_dev,
                    "could not create Rx ring DMA tag.\n");
                goto fail;
        }
        /* Create DMA tag for Rx return descriptor ring. */
        error = bus_dma_tag_create(
            sc->alc_cdata.alc_parent_tag, /* parent */
            ALC_RR_RING_ALIGN, 0,       /* alignment, boundary */
            BUS_SPACE_MAXADDR,          /* lowaddr */
            BUS_SPACE_MAXADDR,          /* highaddr */
            NULL, NULL,                 /* filter, filterarg */
            ALC_RR_RING_SZ,             /* maxsize */
            1,                          /* nsegments */
            ALC_RR_RING_SZ,             /* maxsegsize */
            0,                          /* flags */
            NULL, NULL,                 /* lockfunc, lockarg */
            &sc->alc_cdata.alc_rr_ring_tag);
        if (error != 0) {
                device_printf(sc->alc_dev,
                    "could not create Rx return ring DMA tag.\n");
                goto fail;
        }

        /* Create DMA tag for coalescing message block. */
        error = bus_dma_tag_create(
            sc->alc_cdata.alc_parent_tag, /* parent */
            ALC_CMB_ALIGN, 0,           /* alignment, boundary */
            BUS_SPACE_MAXADDR,          /* lowaddr */
            BUS_SPACE_MAXADDR,          /* highaddr */
            NULL, NULL,                 /* filter, filterarg */
            ALC_CMB_SZ,                 /* maxsize */
            1,                          /* nsegments */
            ALC_CMB_SZ,                 /* maxsegsize */
            0,                          /* flags */
            NULL, NULL,                 /* lockfunc, lockarg */
            &sc->alc_cdata.alc_cmb_tag);
        if (error != 0) {
                device_printf(sc->alc_dev,
                    "could not create CMB DMA tag.\n");
                goto fail;
        }
        /* Create DMA tag for status message block. */
        error = bus_dma_tag_create(
            sc->alc_cdata.alc_parent_tag, /* parent */
            ALC_SMB_ALIGN, 0,           /* alignment, boundary */
            BUS_SPACE_MAXADDR,          /* lowaddr */
            BUS_SPACE_MAXADDR,          /* highaddr */
            NULL, NULL,                 /* filter, filterarg */
            ALC_SMB_SZ,                 /* maxsize */
            1,                          /* nsegments */
            ALC_SMB_SZ,                 /* maxsegsize */
            0,                          /* flags */
            NULL, NULL,                 /* lockfunc, lockarg */
            &sc->alc_cdata.alc_smb_tag);
        if (error != 0) {
                device_printf(sc->alc_dev,
                    "could not create SMB DMA tag.\n");
                goto fail;
        }

        /* Allocate DMA'able memory and load the DMA map for Tx ring. */
        error = bus_dmamem_alloc(sc->alc_cdata.alc_tx_ring_tag,
            (void **)&sc->alc_rdata.alc_tx_ring,
            BUS_DMA_WAITOK | BUS_DMA_ZERO | BUS_DMA_COHERENT,
            &sc->alc_cdata.alc_tx_ring_map);
        if (error != 0) {
                device_printf(sc->alc_dev,
                    "could not allocate DMA'able memory for Tx ring.\n");
                goto fail;
        }
        ctx.alc_busaddr = 0;
        error = bus_dmamap_load(sc->alc_cdata.alc_tx_ring_tag,
            sc->alc_cdata.alc_tx_ring_map, sc->alc_rdata.alc_tx_ring,
            ALC_TX_RING_SZ, alc_dmamap_cb, &ctx, 0);
        if (error != 0 || ctx.alc_busaddr == 0) {
                device_printf(sc->alc_dev,
                    "could not load DMA'able memory for Tx ring.\n");
                goto fail;
        }
        sc->alc_rdata.alc_tx_ring_paddr = ctx.alc_busaddr;

        /* Allocate DMA'able memory and load the DMA map for Rx ring. */
        error = bus_dmamem_alloc(sc->alc_cdata.alc_rx_ring_tag,
            (void **)&sc->alc_rdata.alc_rx_ring,
            BUS_DMA_WAITOK | BUS_DMA_ZERO | BUS_DMA_COHERENT,
            &sc->alc_cdata.alc_rx_ring_map);
        if (error != 0) {
                device_printf(sc->alc_dev,
                    "could not allocate DMA'able memory for Rx ring.\n");
                goto fail;
        }
        ctx.alc_busaddr = 0;
        error = bus_dmamap_load(sc->alc_cdata.alc_rx_ring_tag,
            sc->alc_cdata.alc_rx_ring_map, sc->alc_rdata.alc_rx_ring,
            ALC_RX_RING_SZ, alc_dmamap_cb, &ctx, 0);
        if (error != 0 || ctx.alc_busaddr == 0) {
                device_printf(sc->alc_dev,
                    "could not load DMA'able memory for Rx ring.\n");
                goto fail;
        }
        sc->alc_rdata.alc_rx_ring_paddr = ctx.alc_busaddr;

        /* Allocate DMA'able memory and load the DMA map for Rx return ring. */
        error = bus_dmamem_alloc(sc->alc_cdata.alc_rr_ring_tag,
            (void **)&sc->alc_rdata.alc_rr_ring,
            BUS_DMA_WAITOK | BUS_DMA_ZERO | BUS_DMA_COHERENT,
            &sc->alc_cdata.alc_rr_ring_map);
        if (error != 0) {
                device_printf(sc->alc_dev,
                    "could not allocate DMA'able memory for Rx return ring.\n");
                goto fail;
        }
        ctx.alc_busaddr = 0;
        error = bus_dmamap_load(sc->alc_cdata.alc_rr_ring_tag,
            sc->alc_cdata.alc_rr_ring_map, sc->alc_rdata.alc_rr_ring,
            ALC_RR_RING_SZ, alc_dmamap_cb, &ctx, 0);
        if (error != 0 || ctx.alc_busaddr == 0) {
                device_printf(sc->alc_dev,
                    "could not load DMA'able memory for Tx ring.\n");
                goto fail;
        }
        sc->alc_rdata.alc_rr_ring_paddr = ctx.alc_busaddr;

        /* Allocate DMA'able memory and load the DMA map for CMB. */
        error = bus_dmamem_alloc(sc->alc_cdata.alc_cmb_tag,
            (void **)&sc->alc_rdata.alc_cmb,
            BUS_DMA_WAITOK | BUS_DMA_ZERO | BUS_DMA_COHERENT,
            &sc->alc_cdata.alc_cmb_map);
        if (error != 0) {
                device_printf(sc->alc_dev,
                    "could not allocate DMA'able memory for CMB.\n");
                goto fail;
        }
        ctx.alc_busaddr = 0;
        error = bus_dmamap_load(sc->alc_cdata.alc_cmb_tag,
            sc->alc_cdata.alc_cmb_map, sc->alc_rdata.alc_cmb,
            ALC_CMB_SZ, alc_dmamap_cb, &ctx, 0);
        if (error != 0 || ctx.alc_busaddr == 0) {
                device_printf(sc->alc_dev,
                    "could not load DMA'able memory for CMB.\n");
                goto fail;
        }
        sc->alc_rdata.alc_cmb_paddr = ctx.alc_busaddr;

        /* Allocate DMA'able memory and load the DMA map for SMB. */
        error = bus_dmamem_alloc(sc->alc_cdata.alc_smb_tag,
            (void **)&sc->alc_rdata.alc_smb,
            BUS_DMA_WAITOK | BUS_DMA_ZERO | BUS_DMA_COHERENT,
            &sc->alc_cdata.alc_smb_map);
        if (error != 0) {
                device_printf(sc->alc_dev,
                    "could not allocate DMA'able memory for SMB.\n");
                goto fail;
        }
        ctx.alc_busaddr = 0;
        error = bus_dmamap_load(sc->alc_cdata.alc_smb_tag,
            sc->alc_cdata.alc_smb_map, sc->alc_rdata.alc_smb,
            ALC_SMB_SZ, alc_dmamap_cb, &ctx, 0);
        if (error != 0 || ctx.alc_busaddr == 0) {
                device_printf(sc->alc_dev,
                    "could not load DMA'able memory for CMB.\n");
                goto fail;
        }
        sc->alc_rdata.alc_smb_paddr = ctx.alc_busaddr;

        /* Make sure we've not crossed 4GB boundary. */
        if (lowaddr != BUS_SPACE_MAXADDR_32BIT &&
            (error = alc_check_boundary(sc)) != 0) {
                device_printf(sc->alc_dev, "4GB boundary crossed, "
                    "switching to 32bit DMA addressing mode.\n");
                alc_dma_free(sc);
                /*
                 * Limit max allowable DMA address space to 32bit
                 * and try again.
                 */
                lowaddr = BUS_SPACE_MAXADDR_32BIT;
                goto again;
        }

        /*
         * Create Tx buffer parent tag.
         * AR81[3567]x allows 64bit DMA addressing of Tx/Rx buffers
         * so it needs separate parent DMA tag as parent DMA address
         * space could be restricted to be within 32bit address space
         * by 4GB boundary crossing.
         */
        error = bus_dma_tag_create(
            bus_get_dma_tag(sc->alc_dev), /* parent */
            1, 0,                       /* alignment, boundary */
            lowaddr,                    /* lowaddr */
            BUS_SPACE_MAXADDR,          /* highaddr */
            NULL, NULL,                 /* filter, filterarg */
            BUS_SPACE_MAXSIZE_32BIT,    /* maxsize */
            0,                          /* nsegments */
            BUS_SPACE_MAXSIZE_32BIT,    /* maxsegsize */
            0,                          /* flags */
            NULL, NULL,                 /* lockfunc, lockarg */
            &sc->alc_cdata.alc_buffer_tag);
        if (error != 0) {
                device_printf(sc->alc_dev,
                    "could not create parent buffer DMA tag.\n");
                goto fail;
        }

        /* Create DMA tag for Tx buffers. */
        error = bus_dma_tag_create(
            sc->alc_cdata.alc_buffer_tag, /* parent */
            1, 0,                       /* alignment, boundary */
            BUS_SPACE_MAXADDR,          /* lowaddr */
            BUS_SPACE_MAXADDR,          /* highaddr */
            NULL, NULL,                 /* filter, filterarg */
            ALC_TSO_MAXSIZE,            /* maxsize */
            ALC_MAXTXSEGS,              /* nsegments */
            ALC_TSO_MAXSEGSIZE,         /* maxsegsize */
            0,                          /* flags */
            NULL, NULL,                 /* lockfunc, lockarg */
            &sc->alc_cdata.alc_tx_tag);
        if (error != 0) {
                device_printf(sc->alc_dev, "could not create Tx DMA tag.\n");
                goto fail;
        }

        /* Create DMA tag for Rx buffers. */
        error = bus_dma_tag_create(
            sc->alc_cdata.alc_buffer_tag, /* parent */
            ALC_RX_BUF_ALIGN, 0,        /* alignment, boundary */
            BUS_SPACE_MAXADDR,          /* lowaddr */
            BUS_SPACE_MAXADDR,          /* highaddr */
            NULL, NULL,                 /* filter, filterarg */
            MCLBYTES,                   /* maxsize */
            1,                          /* nsegments */
            MCLBYTES,                   /* maxsegsize */
            0,                          /* flags */
            NULL, NULL,                 /* lockfunc, lockarg */
            &sc->alc_cdata.alc_rx_tag);
        if (error != 0) {
                device_printf(sc->alc_dev, "could not create Rx DMA tag.\n");
                goto fail;
        }
        /* Create DMA maps for Tx buffers. */
        for (i = 0; i < ALC_TX_RING_CNT; i++) {
                txd = &sc->alc_cdata.alc_txdesc[i];
                txd->tx_m = NULL;
                txd->tx_dmamap = NULL;
                error = bus_dmamap_create(sc->alc_cdata.alc_tx_tag, 0,
                    &txd->tx_dmamap);
                if (error != 0) {
                        device_printf(sc->alc_dev,
                            "could not create Tx dmamap.\n");
                        goto fail;
                }
        }
        /* Create DMA maps for Rx buffers. */
        if ((error = bus_dmamap_create(sc->alc_cdata.alc_rx_tag, 0,
            &sc->alc_cdata.alc_rx_sparemap)) != 0) {
                device_printf(sc->alc_dev,
                    "could not create spare Rx dmamap.\n");
                goto fail;
        }
        for (i = 0; i < ALC_RX_RING_CNT; i++) {
                rxd = &sc->alc_cdata.alc_rxdesc[i];
                rxd->rx_m = NULL;
                rxd->rx_dmamap = NULL;
                error = bus_dmamap_create(sc->alc_cdata.alc_rx_tag, 0,
                    &rxd->rx_dmamap);
                if (error != 0) {
                        device_printf(sc->alc_dev,
                            "could not create Rx dmamap.\n");
                        goto fail;
                }
        }

fail:
        return (error);
}

static void
alc_dma_free(struct alc_softc *sc)
{
        struct alc_txdesc *txd;
        struct alc_rxdesc *rxd;
        int i;

        /* Tx buffers. */
        if (sc->alc_cdata.alc_tx_tag != NULL) {
                for (i = 0; i < ALC_TX_RING_CNT; i++) {
                        txd = &sc->alc_cdata.alc_txdesc[i];
                        if (txd->tx_dmamap != NULL) {
                                bus_dmamap_destroy(sc->alc_cdata.alc_tx_tag,
                                    txd->tx_dmamap);
                                txd->tx_dmamap = NULL;
                        }
                }
                bus_dma_tag_destroy(sc->alc_cdata.alc_tx_tag);
                sc->alc_cdata.alc_tx_tag = NULL;
        }
        /* Rx buffers */
        if (sc->alc_cdata.alc_rx_tag != NULL) {
                for (i = 0; i < ALC_RX_RING_CNT; i++) {
                        rxd = &sc->alc_cdata.alc_rxdesc[i];
                        if (rxd->rx_dmamap != NULL) {
                                bus_dmamap_destroy(sc->alc_cdata.alc_rx_tag,
                                    rxd->rx_dmamap);
                                rxd->rx_dmamap = NULL;
                        }
                }
                if (sc->alc_cdata.alc_rx_sparemap != NULL) {
                        bus_dmamap_destroy(sc->alc_cdata.alc_rx_tag,
                            sc->alc_cdata.alc_rx_sparemap);
                        sc->alc_cdata.alc_rx_sparemap = NULL;
                }
                bus_dma_tag_destroy(sc->alc_cdata.alc_rx_tag);
                sc->alc_cdata.alc_rx_tag = NULL;
        }
        /* Tx descriptor ring. */
        if (sc->alc_cdata.alc_tx_ring_tag != NULL) {
                if (sc->alc_rdata.alc_tx_ring_paddr != 0)
                        bus_dmamap_unload(sc->alc_cdata.alc_tx_ring_tag,
                            sc->alc_cdata.alc_tx_ring_map);
                if (sc->alc_rdata.alc_tx_ring != NULL)
                        bus_dmamem_free(sc->alc_cdata.alc_tx_ring_tag,
                            sc->alc_rdata.alc_tx_ring,
                            sc->alc_cdata.alc_tx_ring_map);
                sc->alc_rdata.alc_tx_ring_paddr = 0;
                sc->alc_rdata.alc_tx_ring = NULL;
                bus_dma_tag_destroy(sc->alc_cdata.alc_tx_ring_tag);
                sc->alc_cdata.alc_tx_ring_tag = NULL;
        }
        /* Rx ring. */
        if (sc->alc_cdata.alc_rx_ring_tag != NULL) {
                if (sc->alc_rdata.alc_rx_ring_paddr != 0)
                        bus_dmamap_unload(sc->alc_cdata.alc_rx_ring_tag,
                            sc->alc_cdata.alc_rx_ring_map);
                if (sc->alc_rdata.alc_rx_ring != NULL)
                        bus_dmamem_free(sc->alc_cdata.alc_rx_ring_tag,
                            sc->alc_rdata.alc_rx_ring,
                            sc->alc_cdata.alc_rx_ring_map);
                sc->alc_rdata.alc_rx_ring_paddr = 0;
                sc->alc_rdata.alc_rx_ring = NULL;
                bus_dma_tag_destroy(sc->alc_cdata.alc_rx_ring_tag);
                sc->alc_cdata.alc_rx_ring_tag = NULL;
        }
        /* Rx return ring. */
        if (sc->alc_cdata.alc_rr_ring_tag != NULL) {
                if (sc->alc_rdata.alc_rr_ring_paddr != 0)
                        bus_dmamap_unload(sc->alc_cdata.alc_rr_ring_tag,
                            sc->alc_cdata.alc_rr_ring_map);
                if (sc->alc_rdata.alc_rr_ring != NULL)
                        bus_dmamem_free(sc->alc_cdata.alc_rr_ring_tag,
                            sc->alc_rdata.alc_rr_ring,
                            sc->alc_cdata.alc_rr_ring_map);
                sc->alc_rdata.alc_rr_ring_paddr = 0;
                sc->alc_rdata.alc_rr_ring = NULL;
                bus_dma_tag_destroy(sc->alc_cdata.alc_rr_ring_tag);
                sc->alc_cdata.alc_rr_ring_tag = NULL;
        }
        /* CMB block */
        if (sc->alc_cdata.alc_cmb_tag != NULL) {
                if (sc->alc_rdata.alc_cmb_paddr != 0)
                        bus_dmamap_unload(sc->alc_cdata.alc_cmb_tag,
                            sc->alc_cdata.alc_cmb_map);
                if (sc->alc_rdata.alc_cmb != NULL)
                        bus_dmamem_free(sc->alc_cdata.alc_cmb_tag,
                            sc->alc_rdata.alc_cmb,
                            sc->alc_cdata.alc_cmb_map);         
                sc->alc_rdata.alc_cmb_paddr = 0;
                sc->alc_rdata.alc_cmb = NULL;
                bus_dma_tag_destroy(sc->alc_cdata.alc_cmb_tag);
                sc->alc_cdata.alc_cmb_tag = NULL;
        }
        /* SMB block */
        if (sc->alc_cdata.alc_smb_tag != NULL) {
                if (sc->alc_rdata.alc_smb_paddr != 0)
                        bus_dmamap_unload(sc->alc_cdata.alc_smb_tag,
                            sc->alc_cdata.alc_smb_map);
                if (sc->alc_rdata.alc_smb != NULL)
                        bus_dmamem_free(sc->alc_cdata.alc_smb_tag,
                            sc->alc_rdata.alc_smb,
                            sc->alc_cdata.alc_smb_map);
                sc->alc_rdata.alc_smb_paddr = 0;
                sc->alc_rdata.alc_smb = NULL;
                bus_dma_tag_destroy(sc->alc_cdata.alc_smb_tag);
                sc->alc_cdata.alc_smb_tag = NULL;
        }
        if (sc->alc_cdata.alc_buffer_tag != NULL) {
                bus_dma_tag_destroy(sc->alc_cdata.alc_buffer_tag);
                sc->alc_cdata.alc_buffer_tag = NULL;
        }
        if (sc->alc_cdata.alc_parent_tag != NULL) {
                bus_dma_tag_destroy(sc->alc_cdata.alc_parent_tag);
                sc->alc_cdata.alc_parent_tag = NULL;
        }
}

static int
alc_shutdown(device_t dev)
{

        return (alc_suspend(dev));
}

/*
 * Note, this driver resets the link speed to 10/100Mbps by
 * restarting auto-negotiation in suspend/shutdown phase but we
 * don't know whether that auto-negotiation would succeed or not
 * as driver has no control after powering off/suspend operation.
 * If the renegotiation fail WOL may not work. Running at 1Gbps
 * will draw more power than 375mA at 3.3V which is specified in
 * PCI specification and that would result in complete
 * shutdowning power to ethernet controller.
 *
 * TODO
 * Save current negotiated media speed/duplex/flow-control to
 * softc and restore the same link again after resuming. PHY
 * handling such as power down/resetting to 100Mbps may be better
 * handled in suspend method in phy driver.
 */
static void
alc_setlinkspeed(struct alc_softc *sc)
{
        struct mii_data *mii;
        int aneg, i;

        mii = device_get_softc(sc->alc_miibus);
        mii_pollstat(mii);
        aneg = 0;
        if ((mii->mii_media_status & (IFM_ACTIVE | IFM_AVALID)) ==
            (IFM_ACTIVE | IFM_AVALID)) {
                switch IFM_SUBTYPE(mii->mii_media_active) {
                case IFM_10_T:
                case IFM_100_TX:
                        return;
                case IFM_1000_T:
                        aneg++;
                        break;
                default:
                        break;
                }
        }
        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr, MII_100T2CR, 0);
        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
            MII_ANAR, ANAR_TX_FD | ANAR_TX | ANAR_10_FD | ANAR_10 | ANAR_CSMA);
        alc_miibus_writereg(sc->alc_dev, sc->alc_phyaddr,
            MII_BMCR, BMCR_RESET | BMCR_AUTOEN | BMCR_STARTNEG);
        DELAY(1000);
        if (aneg != 0) {
                /*
                 * Poll link state until alc(4) get a 10/100Mbps link.
                 */
                for (i = 0; i < MII_ANEGTICKS_GIGE; i++) {
                        mii_pollstat(mii);
                        if ((mii->mii_media_status & (IFM_ACTIVE | IFM_AVALID))
                            == (IFM_ACTIVE | IFM_AVALID)) {
                                switch (IFM_SUBTYPE(
                                    mii->mii_media_active)) {
                                case IFM_10_T:
                                case IFM_100_TX:
                                        alc_mac_config(sc);
                                        return;
                                default:
                                        break;
                                }
                        }
                        ALC_UNLOCK(sc);
                        pause("alclnk", hz);
                        ALC_LOCK(sc);
                }
                if (i == MII_ANEGTICKS_GIGE)
                        device_printf(sc->alc_dev,
                            "establishing a link failed, WOL may not work!");
        }
        /*
         * No link, force MAC to have 100Mbps, full-duplex link.
         * This is the last resort and may/may not work.
         */
        mii->mii_media_status = IFM_AVALID | IFM_ACTIVE;
        mii->mii_media_active = IFM_ETHER | IFM_100_TX | IFM_FDX;
        alc_mac_config(sc);
}

static void
alc_setwol(struct alc_softc *sc)
{

        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0)
                alc_setwol_816x(sc);
        else
                alc_setwol_813x(sc);
}

static void
alc_setwol_813x(struct alc_softc *sc)
{
        if_t ifp;
        uint32_t reg, pmcs;
        uint16_t pmstat;

        ALC_LOCK_ASSERT(sc);

        alc_disable_l0s_l1(sc);
        ifp = sc->alc_ifp;
        if ((sc->alc_flags & ALC_FLAG_PM) == 0) {
                /* Disable WOL. */
                CSR_WRITE_4(sc, ALC_WOL_CFG, 0);
                reg = CSR_READ_4(sc, ALC_PCIE_PHYMISC);
                reg |= PCIE_PHYMISC_FORCE_RCV_DET;
                CSR_WRITE_4(sc, ALC_PCIE_PHYMISC, reg);
                /* Force PHY power down. */
                alc_phy_down(sc);
                CSR_WRITE_4(sc, ALC_MASTER_CFG,
                    CSR_READ_4(sc, ALC_MASTER_CFG) | MASTER_CLK_SEL_DIS);
                return;
        }

        if ((if_getcapenable(ifp) & IFCAP_WOL) != 0) {
                if ((sc->alc_flags & ALC_FLAG_FASTETHER) == 0)
                        alc_setlinkspeed(sc);
                CSR_WRITE_4(sc, ALC_MASTER_CFG,
                    CSR_READ_4(sc, ALC_MASTER_CFG) & ~MASTER_CLK_SEL_DIS);
        }

        pmcs = 0;
        if ((if_getcapenable(ifp) & IFCAP_WOL_MAGIC) != 0)
                pmcs |= WOL_CFG_MAGIC | WOL_CFG_MAGIC_ENB;
        CSR_WRITE_4(sc, ALC_WOL_CFG, pmcs);
        reg = CSR_READ_4(sc, ALC_MAC_CFG);
        reg &= ~(MAC_CFG_DBG | MAC_CFG_PROMISC | MAC_CFG_ALLMULTI |
            MAC_CFG_BCAST);
        if ((if_getcapenable(ifp) & IFCAP_WOL_MCAST) != 0)
                reg |= MAC_CFG_ALLMULTI | MAC_CFG_BCAST;
        if ((if_getcapenable(ifp) & IFCAP_WOL) != 0)
                reg |= MAC_CFG_RX_ENB;
        CSR_WRITE_4(sc, ALC_MAC_CFG, reg);

        reg = CSR_READ_4(sc, ALC_PCIE_PHYMISC);
        reg |= PCIE_PHYMISC_FORCE_RCV_DET;
        CSR_WRITE_4(sc, ALC_PCIE_PHYMISC, reg);
        if ((if_getcapenable(ifp) & IFCAP_WOL) == 0) {
                /* WOL disabled, PHY power down. */
                alc_phy_down(sc);
                CSR_WRITE_4(sc, ALC_MASTER_CFG,
                    CSR_READ_4(sc, ALC_MASTER_CFG) | MASTER_CLK_SEL_DIS);
        }
        /* Request PME. */
        pmstat = pci_read_config(sc->alc_dev,
            sc->alc_pmcap + PCIR_POWER_STATUS, 2);
        pmstat &= ~(PCIM_PSTAT_PME | PCIM_PSTAT_PMEENABLE);
        if ((if_getcapenable(ifp) & IFCAP_WOL) != 0)
                pmstat |= PCIM_PSTAT_PME | PCIM_PSTAT_PMEENABLE;
        pci_write_config(sc->alc_dev,
            sc->alc_pmcap + PCIR_POWER_STATUS, pmstat, 2);
}

static void
alc_setwol_816x(struct alc_softc *sc)
{
        if_t ifp;
        uint32_t gphy, mac, master, pmcs, reg;
        uint16_t pmstat;

        ALC_LOCK_ASSERT(sc);

        ifp = sc->alc_ifp;
        master = CSR_READ_4(sc, ALC_MASTER_CFG);
        master &= ~MASTER_CLK_SEL_DIS;
        gphy = CSR_READ_4(sc, ALC_GPHY_CFG);
        gphy &= ~(GPHY_CFG_EXT_RESET | GPHY_CFG_LED_MODE | GPHY_CFG_100AB_ENB |
            GPHY_CFG_PHY_PLL_ON);
        gphy |= GPHY_CFG_HIB_EN | GPHY_CFG_HIB_PULSE | GPHY_CFG_SEL_ANA_RESET;
        if ((sc->alc_flags & ALC_FLAG_PM) == 0) {
                CSR_WRITE_4(sc, ALC_WOL_CFG, 0);
                gphy |= GPHY_CFG_PHY_IDDQ | GPHY_CFG_PWDOWN_HW;
                mac = CSR_READ_4(sc, ALC_MAC_CFG);
        } else {
                if ((if_getcapenable(ifp) & IFCAP_WOL) != 0) {
                        gphy |= GPHY_CFG_EXT_RESET;
                        if ((sc->alc_flags & ALC_FLAG_FASTETHER) == 0)
                                alc_setlinkspeed(sc);
                }
                pmcs = 0;
                if ((if_getcapenable(ifp) & IFCAP_WOL_MAGIC) != 0)
                        pmcs |= WOL_CFG_MAGIC | WOL_CFG_MAGIC_ENB;
                CSR_WRITE_4(sc, ALC_WOL_CFG, pmcs);
                mac = CSR_READ_4(sc, ALC_MAC_CFG);
                mac &= ~(MAC_CFG_DBG | MAC_CFG_PROMISC | MAC_CFG_ALLMULTI |
                    MAC_CFG_BCAST);
                if ((if_getcapenable(ifp) & IFCAP_WOL_MCAST) != 0)
                        mac |= MAC_CFG_ALLMULTI | MAC_CFG_BCAST;
                if ((if_getcapenable(ifp) & IFCAP_WOL) != 0)
                        mac |= MAC_CFG_RX_ENB;
                alc_miiext_writereg(sc, MII_EXT_ANEG, MII_EXT_ANEG_S3DIG10,
                    ANEG_S3DIG10_SL);
        }

        /* Enable OSC. */
        reg = CSR_READ_4(sc, ALC_MISC);
        reg &= ~MISC_INTNLOSC_OPEN;
        CSR_WRITE_4(sc, ALC_MISC, reg);
        reg |= MISC_INTNLOSC_OPEN;
        CSR_WRITE_4(sc, ALC_MISC, reg);
        CSR_WRITE_4(sc, ALC_MASTER_CFG, master);
        CSR_WRITE_4(sc, ALC_MAC_CFG, mac);
        CSR_WRITE_4(sc, ALC_GPHY_CFG, gphy);
        reg = CSR_READ_4(sc, ALC_PDLL_TRNS1);
        reg |= PDLL_TRNS1_D3PLLOFF_ENB;
        CSR_WRITE_4(sc, ALC_PDLL_TRNS1, reg);

        if ((sc->alc_flags & ALC_FLAG_PM) != 0) {
                /* Request PME. */
                pmstat = pci_read_config(sc->alc_dev,
                    sc->alc_pmcap + PCIR_POWER_STATUS, 2);
                pmstat &= ~(PCIM_PSTAT_PME | PCIM_PSTAT_PMEENABLE);
                if ((if_getcapenable(ifp) & IFCAP_WOL) != 0)
                        pmstat |= PCIM_PSTAT_PME | PCIM_PSTAT_PMEENABLE;
                pci_write_config(sc->alc_dev,
                    sc->alc_pmcap + PCIR_POWER_STATUS, pmstat, 2);
        }
}

static int
alc_suspend(device_t dev)
{
        struct alc_softc *sc;

        sc = device_get_softc(dev);

        ALC_LOCK(sc);
        alc_stop(sc);
        alc_setwol(sc);
        ALC_UNLOCK(sc);

        return (0);
}

static int
alc_resume(device_t dev)
{
        struct alc_softc *sc;
        if_t ifp;
        uint16_t pmstat;

        sc = device_get_softc(dev);

        ALC_LOCK(sc);
        if ((sc->alc_flags & ALC_FLAG_PM) != 0) {
                /* Disable PME and clear PME status. */
                pmstat = pci_read_config(sc->alc_dev,
                    sc->alc_pmcap + PCIR_POWER_STATUS, 2);
                if ((pmstat & PCIM_PSTAT_PMEENABLE) != 0) {
                        pmstat &= ~PCIM_PSTAT_PMEENABLE;
                        pci_write_config(sc->alc_dev,
                            sc->alc_pmcap + PCIR_POWER_STATUS, pmstat, 2);
                }
        }
        /* Reset PHY. */
        alc_phy_reset(sc);
        ifp = sc->alc_ifp;
        if ((if_getflags(ifp) & IFF_UP) != 0) {
                if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
                alc_init_locked(sc);
        }
        ALC_UNLOCK(sc);

        return (0);
}

static int
alc_encap(struct alc_softc *sc, struct mbuf **m_head)
{
        struct alc_txdesc *txd, *txd_last;
        struct tx_desc *desc;
        struct mbuf *m;
        struct ip *ip;
        struct tcphdr *tcp;
        bus_dma_segment_t txsegs[ALC_MAXTXSEGS];
        bus_dmamap_t map;
        uint32_t cflags, hdrlen, ip_off, poff, vtag;
        int error, idx, nsegs, prod;

        ALC_LOCK_ASSERT(sc);

        M_ASSERTPKTHDR((*m_head));

        m = *m_head;
        ip = NULL;
        tcp = NULL;
        ip_off = poff = 0;
        if ((m->m_pkthdr.csum_flags & (ALC_CSUM_FEATURES | CSUM_TSO)) != 0) {
                /*
                 * AR81[3567]x requires offset of TCP/UDP header in its
                 * Tx descriptor to perform Tx checksum offloading. TSO
                 * also requires TCP header offset and modification of
                 * IP/TCP header. This kind of operation takes many CPU
                 * cycles on FreeBSD so fast host CPU is required to get
                 * smooth TSO performance.
                 */
                struct ether_header *eh;

                if (M_WRITABLE(m) == 0) {
                        /* Get a writable copy. */
                        m = m_dup(*m_head, M_NOWAIT);
                        /* Release original mbufs. */
                        m_freem(*m_head);
                        if (m == NULL) {
                                *m_head = NULL;
                                return (ENOBUFS);
                        }
                        *m_head = m;
                }

                ip_off = sizeof(struct ether_header);
                m = m_pullup(m, ip_off);
                if (m == NULL) {
                        *m_head = NULL;
                        return (ENOBUFS);
                }
                eh = mtod(m, struct ether_header *);
                /*
                 * Check if hardware VLAN insertion is off.
                 * Additional check for LLC/SNAP frame?
                 */
                if (eh->ether_type == htons(ETHERTYPE_VLAN)) {
                        ip_off = sizeof(struct ether_vlan_header);
                        m = m_pullup(m, ip_off);
                        if (m == NULL) {
                                *m_head = NULL;
                                return (ENOBUFS);
                        }
                }
                m = m_pullup(m, ip_off + sizeof(struct ip));
                if (m == NULL) {
                        *m_head = NULL;
                        return (ENOBUFS);
                }
                ip = (struct ip *)(mtod(m, char *) + ip_off);
                poff = ip_off + (ip->ip_hl << 2);
                if ((m->m_pkthdr.csum_flags & CSUM_TSO) != 0) {
                        m = m_pullup(m, poff + sizeof(struct tcphdr));
                        if (m == NULL) {
                                *m_head = NULL;
                                return (ENOBUFS);
                        }
                        tcp = (struct tcphdr *)(mtod(m, char *) + poff);
                        m = m_pullup(m, poff + (tcp->th_off << 2));
                        if (m == NULL) {
                                *m_head = NULL;
                                return (ENOBUFS);
                        }
                        /*
                         * Due to strict adherence of Microsoft NDIS
                         * Large Send specification, hardware expects
                         * a pseudo TCP checksum inserted by upper
                         * stack. Unfortunately the pseudo TCP
                         * checksum that NDIS refers to does not include
                         * TCP payload length so driver should recompute
                         * the pseudo checksum here. Hopefully this
                         * wouldn't be much burden on modern CPUs.
                         *
                         * Reset IP checksum and recompute TCP pseudo
                         * checksum as NDIS specification said.
                         */
                        ip = (struct ip *)(mtod(m, char *) + ip_off);
                        tcp = (struct tcphdr *)(mtod(m, char *) + poff);
                        ip->ip_sum = 0;
                        tcp->th_sum = in_pseudo(ip->ip_src.s_addr,
                            ip->ip_dst.s_addr, htons(IPPROTO_TCP));
                }
                *m_head = m;
        }

        prod = sc->alc_cdata.alc_tx_prod;
        txd = &sc->alc_cdata.alc_txdesc[prod];
        txd_last = txd;
        map = txd->tx_dmamap;

        error = bus_dmamap_load_mbuf_sg(sc->alc_cdata.alc_tx_tag, map,
            *m_head, txsegs, &nsegs, 0);
        if (error == EFBIG) {
                m = m_collapse(*m_head, M_NOWAIT, ALC_MAXTXSEGS);
                if (m == NULL) {
                        m_freem(*m_head);
                        *m_head = NULL;
                        return (ENOMEM);
                }
                *m_head = m;
                error = bus_dmamap_load_mbuf_sg(sc->alc_cdata.alc_tx_tag, map,
                    *m_head, txsegs, &nsegs, 0);
                if (error != 0) {
                        m_freem(*m_head);
                        *m_head = NULL;
                        return (error);
                }
        } else if (error != 0)
                return (error);
        if (nsegs == 0) {
                m_freem(*m_head);
                *m_head = NULL;
                return (EIO);
        }

        /* Check descriptor overrun. */
        if (sc->alc_cdata.alc_tx_cnt + nsegs >= ALC_TX_RING_CNT - 3) {
                bus_dmamap_unload(sc->alc_cdata.alc_tx_tag, map);
                return (ENOBUFS);
        }
        bus_dmamap_sync(sc->alc_cdata.alc_tx_tag, map, BUS_DMASYNC_PREWRITE);

        m = *m_head;
        cflags = TD_ETHERNET;
        vtag = 0;
        desc = NULL;
        idx = 0;
        /* Configure VLAN hardware tag insertion. */
        if ((m->m_flags & M_VLANTAG) != 0) {
                vtag = htons(m->m_pkthdr.ether_vtag);
                vtag = (vtag << TD_VLAN_SHIFT) & TD_VLAN_MASK;
                cflags |= TD_INS_VLAN_TAG;
        }
        if ((m->m_pkthdr.csum_flags & CSUM_TSO) != 0) {
                /* Request TSO and set MSS. */
                cflags |= TD_TSO | TD_TSO_DESCV1;
                cflags |= ((uint32_t)m->m_pkthdr.tso_segsz << TD_MSS_SHIFT) &
                    TD_MSS_MASK;
                /* Set TCP header offset. */
                cflags |= (poff << TD_TCPHDR_OFFSET_SHIFT) &
                    TD_TCPHDR_OFFSET_MASK;
                /*
                 * AR81[3567]x requires the first buffer should
                 * only hold IP/TCP header data. Payload should
                 * be handled in other descriptors.
                 */
                hdrlen = poff + (tcp->th_off << 2);
                desc = &sc->alc_rdata.alc_tx_ring[prod];
                desc->len = htole32(TX_BYTES(hdrlen | vtag));
                desc->flags = htole32(cflags);
                desc->addr = htole64(txsegs[0].ds_addr);
                sc->alc_cdata.alc_tx_cnt++;
                ALC_DESC_INC(prod, ALC_TX_RING_CNT);
                if (m->m_len - hdrlen > 0) {
                        /* Handle remaining payload of the first fragment. */
                        desc = &sc->alc_rdata.alc_tx_ring[prod];
                        desc->len = htole32(TX_BYTES((m->m_len - hdrlen) |
                            vtag));
                        desc->flags = htole32(cflags);
                        desc->addr = htole64(txsegs[0].ds_addr + hdrlen);
                        sc->alc_cdata.alc_tx_cnt++;
                        ALC_DESC_INC(prod, ALC_TX_RING_CNT);
                }
                /* Handle remaining fragments. */
                idx = 1;
        } else if ((m->m_pkthdr.csum_flags & ALC_CSUM_FEATURES) != 0) {
                /* Configure Tx checksum offload. */
#ifdef ALC_USE_CUSTOM_CSUM
                cflags |= TD_CUSTOM_CSUM;
                /* Set checksum start offset. */
                cflags |= ((poff >> 1) << TD_PLOAD_OFFSET_SHIFT) &
                    TD_PLOAD_OFFSET_MASK;
                /* Set checksum insertion position of TCP/UDP. */
                cflags |= (((poff + m->m_pkthdr.csum_data) >> 1) <<
                    TD_CUSTOM_CSUM_OFFSET_SHIFT) & TD_CUSTOM_CSUM_OFFSET_MASK;
#else
                if ((m->m_pkthdr.csum_flags & CSUM_IP) != 0)
                        cflags |= TD_IPCSUM;
                if ((m->m_pkthdr.csum_flags & CSUM_TCP) != 0)
                        cflags |= TD_TCPCSUM;
                if ((m->m_pkthdr.csum_flags & CSUM_UDP) != 0)
                        cflags |= TD_UDPCSUM;
                /* Set TCP/UDP header offset. */
                cflags |= (poff << TD_L4HDR_OFFSET_SHIFT) &
                    TD_L4HDR_OFFSET_MASK;
#endif
        }
        for (; idx < nsegs; idx++) {
                desc = &sc->alc_rdata.alc_tx_ring[prod];
                desc->len = htole32(TX_BYTES(txsegs[idx].ds_len) | vtag);
                desc->flags = htole32(cflags);
                desc->addr = htole64(txsegs[idx].ds_addr);
                sc->alc_cdata.alc_tx_cnt++;
                ALC_DESC_INC(prod, ALC_TX_RING_CNT);
        }
        /* Update producer index. */
        sc->alc_cdata.alc_tx_prod = prod;

        /* Finally set EOP on the last descriptor. */
        prod = (prod + ALC_TX_RING_CNT - 1) % ALC_TX_RING_CNT;
        desc = &sc->alc_rdata.alc_tx_ring[prod];
        desc->flags |= htole32(TD_EOP);

        /* Swap dmamap of the first and the last. */
        txd = &sc->alc_cdata.alc_txdesc[prod];
        map = txd_last->tx_dmamap;
        txd_last->tx_dmamap = txd->tx_dmamap;
        txd->tx_dmamap = map;
        txd->tx_m = m;

        return (0);
}

static void
alc_start(if_t ifp)
{
        struct alc_softc *sc;

        sc = if_getsoftc(ifp);
        ALC_LOCK(sc);
        alc_start_locked(ifp);
        ALC_UNLOCK(sc);
}

static void
alc_start_locked(if_t ifp)
{
        struct alc_softc *sc;
        struct mbuf *m_head;
        int enq;

        sc = if_getsoftc(ifp);

        ALC_LOCK_ASSERT(sc);

        /* Reclaim transmitted frames. */
        if (sc->alc_cdata.alc_tx_cnt >= ALC_TX_DESC_HIWAT)
                alc_txeof(sc);

        if ((if_getdrvflags(ifp) & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
            IFF_DRV_RUNNING || (sc->alc_flags & ALC_FLAG_LINK) == 0)
                return;

        for (enq = 0; !if_sendq_empty(ifp); ) {
                m_head = if_dequeue(ifp);
                if (m_head == NULL)
                        break;
                /*
                 * Pack the data into the transmit ring. If we
                 * don't have room, set the OACTIVE flag and wait
                 * for the NIC to drain the ring.
                 */
                if (alc_encap(sc, &m_head)) {
                        if (m_head == NULL)
                                break;
                        if_sendq_prepend(ifp, m_head);
                        if_setdrvflagbits(ifp, IFF_DRV_OACTIVE, 0);
                        break;
                }

                enq++;
                /*
                 * If there's a BPF listener, bounce a copy of this frame
                 * to him.
                 */
                ETHER_BPF_MTAP(ifp, m_head);
        }

        if (enq > 0)
                alc_start_tx(sc);
}

static void
alc_start_tx(struct alc_softc *sc)
{

        /* Sync descriptors. */
        bus_dmamap_sync(sc->alc_cdata.alc_tx_ring_tag,
            sc->alc_cdata.alc_tx_ring_map, BUS_DMASYNC_PREWRITE);
        /* Kick. Assume we're using normal Tx priority queue. */
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0)
                CSR_WRITE_2(sc, ALC_MBOX_TD_PRI0_PROD_IDX,
                    (uint16_t)sc->alc_cdata.alc_tx_prod);
        else
                CSR_WRITE_4(sc, ALC_MBOX_TD_PROD_IDX,
                    (sc->alc_cdata.alc_tx_prod <<
                    MBOX_TD_PROD_LO_IDX_SHIFT) &
                    MBOX_TD_PROD_LO_IDX_MASK);
        /* Set a timeout in case the chip goes out to lunch. */
        sc->alc_watchdog_timer = ALC_TX_TIMEOUT;
}

static void
alc_watchdog(struct alc_softc *sc)
{
        if_t ifp;

        ALC_LOCK_ASSERT(sc);

        if (sc->alc_watchdog_timer == 0 || --sc->alc_watchdog_timer)
                return;

        ifp = sc->alc_ifp;
        if ((sc->alc_flags & ALC_FLAG_LINK) == 0) {
                if_printf(sc->alc_ifp, "watchdog timeout (lost link)\n");
                if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
                if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
                alc_init_locked(sc);
                return;
        }
        if_printf(sc->alc_ifp, "watchdog timeout -- resetting\n");
        if_inc_counter(ifp, IFCOUNTER_OERRORS, 1);
        if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
        alc_init_locked(sc);
        if (!if_sendq_empty(ifp))
                alc_start_locked(ifp);
}

static int
alc_ioctl(if_t ifp, u_long cmd, caddr_t data)
{
        struct alc_softc *sc;
        struct ifreq *ifr;
        struct mii_data *mii;
        int error, mask;

        sc = if_getsoftc(ifp);
        ifr = (struct ifreq *)data;
        error = 0;
        switch (cmd) {
        case SIOCSIFMTU:
                if (ifr->ifr_mtu < ETHERMIN ||
                    ifr->ifr_mtu > (sc->alc_ident->max_framelen -
                    sizeof(struct ether_vlan_header) - ETHER_CRC_LEN) ||
                    ((sc->alc_flags & ALC_FLAG_JUMBO) == 0 &&
                    ifr->ifr_mtu > ETHERMTU))
                        error = EINVAL;
                else if (if_getmtu(ifp) != ifr->ifr_mtu) {
                        ALC_LOCK(sc);
                        if_setmtu(ifp, ifr->ifr_mtu);
                        /* AR81[3567]x has 13 bits MSS field. */
                        if (if_getmtu(ifp) > ALC_TSO_MTU &&
                            (if_getcapenable(ifp) & IFCAP_TSO4) != 0) {
                                if_setcapenablebit(ifp, 0, IFCAP_TSO4);
                                if_sethwassistbits(ifp, 0, CSUM_TSO);
                                VLAN_CAPABILITIES(ifp);
                        }
                        ALC_UNLOCK(sc);
                }
                break;
        case SIOCSIFFLAGS:
                ALC_LOCK(sc);
                if ((if_getflags(ifp) & IFF_UP) != 0) {
                        if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0 &&
                            ((if_getflags(ifp) ^ sc->alc_if_flags) &
                            (IFF_PROMISC | IFF_ALLMULTI)) != 0)
                                alc_rxfilter(sc);
                        else
                                alc_init_locked(sc);
                } else if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0)
                        alc_stop(sc);
                sc->alc_if_flags = if_getflags(ifp);
                ALC_UNLOCK(sc);
                break;
        case SIOCADDMULTI:
        case SIOCDELMULTI:
                ALC_LOCK(sc);
                if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0)
                        alc_rxfilter(sc);
                ALC_UNLOCK(sc);
                break;
        case SIOCSIFMEDIA:
        case SIOCGIFMEDIA:
                mii = device_get_softc(sc->alc_miibus);
                error = ifmedia_ioctl(ifp, ifr, &mii->mii_media, cmd);
                break;
        case SIOCSIFCAP:
                ALC_LOCK(sc);
                mask = ifr->ifr_reqcap ^ if_getcapenable(ifp);
                if ((mask & IFCAP_TXCSUM) != 0 &&
                    (if_getcapabilities(ifp) & IFCAP_TXCSUM) != 0) {
                        if_togglecapenable(ifp, IFCAP_TXCSUM);
                        if ((if_getcapenable(ifp) & IFCAP_TXCSUM) != 0)
                                if_sethwassistbits(ifp, ALC_CSUM_FEATURES, 0);
                        else
                                if_sethwassistbits(ifp, 0, ALC_CSUM_FEATURES);
                }
                if ((mask & IFCAP_TSO4) != 0 &&
                    (if_getcapabilities(ifp) & IFCAP_TSO4) != 0) {
                        if_togglecapenable(ifp, IFCAP_TSO4);
                        if ((if_getcapenable(ifp) & IFCAP_TSO4) != 0) {
                                /* AR81[3567]x has 13 bits MSS field. */
                                if (if_getmtu(ifp) > ALC_TSO_MTU) {
                                        if_setcapenablebit(ifp, 0, IFCAP_TSO4);
                                        if_sethwassistbits(ifp, 0, CSUM_TSO);
                                } else
                                        if_sethwassistbits(ifp, CSUM_TSO, 0);
                        } else
                                if_sethwassistbits(ifp, 0, CSUM_TSO);
                }
                if ((mask & IFCAP_WOL_MCAST) != 0 &&
                    (if_getcapabilities(ifp) & IFCAP_WOL_MCAST) != 0)
                        if_togglecapenable(ifp, IFCAP_WOL_MCAST);
                if ((mask & IFCAP_WOL_MAGIC) != 0 &&
                    (if_getcapabilities(ifp) & IFCAP_WOL_MAGIC) != 0)
                        if_togglecapenable(ifp, IFCAP_WOL_MAGIC);
                if ((mask & IFCAP_VLAN_HWTAGGING) != 0 &&
                    (if_getcapabilities(ifp) & IFCAP_VLAN_HWTAGGING) != 0) {
                        if_togglecapenable(ifp, IFCAP_VLAN_HWTAGGING);
                        alc_rxvlan(sc);
                }
                if ((mask & IFCAP_VLAN_HWCSUM) != 0 &&
                    (if_getcapabilities(ifp) & IFCAP_VLAN_HWCSUM) != 0)
                        if_togglecapenable(ifp, IFCAP_VLAN_HWCSUM);
                if ((mask & IFCAP_VLAN_HWTSO) != 0 &&
                    (if_getcapabilities(ifp) & IFCAP_VLAN_HWTSO) != 0)
                        if_togglecapenable(ifp, IFCAP_VLAN_HWTSO);
                if ((if_getcapenable(ifp) & IFCAP_VLAN_HWTAGGING) == 0)
                        if_setcapenablebit(ifp, 0,
                            IFCAP_VLAN_HWTSO | IFCAP_VLAN_HWCSUM);
                ALC_UNLOCK(sc);
                VLAN_CAPABILITIES(ifp);
                break;
        default:
                error = ether_ioctl(ifp, cmd, data);
                break;
        }

        return (error);
}

static void
alc_mac_config(struct alc_softc *sc)
{
        struct mii_data *mii;
        uint32_t reg;

        ALC_LOCK_ASSERT(sc);

        mii = device_get_softc(sc->alc_miibus);
        reg = CSR_READ_4(sc, ALC_MAC_CFG);
        reg &= ~(MAC_CFG_FULL_DUPLEX | MAC_CFG_TX_FC | MAC_CFG_RX_FC |
            MAC_CFG_SPEED_MASK);
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0 ||
            sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8151 ||
            sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8151_V2 ||
            sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8152_B2)
                reg |= MAC_CFG_HASH_ALG_CRC32 | MAC_CFG_SPEED_MODE_SW;
        /* Reprogram MAC with resolved speed/duplex. */
        switch (IFM_SUBTYPE(mii->mii_media_active)) {
        case IFM_10_T:
        case IFM_100_TX:
                reg |= MAC_CFG_SPEED_10_100;
                break;
        case IFM_1000_T:
                reg |= MAC_CFG_SPEED_1000;
                break;
        }
        if ((IFM_OPTIONS(mii->mii_media_active) & IFM_FDX) != 0) {
                reg |= MAC_CFG_FULL_DUPLEX;
                if ((IFM_OPTIONS(mii->mii_media_active) & IFM_ETH_TXPAUSE) != 0)
                        reg |= MAC_CFG_TX_FC;
                if ((IFM_OPTIONS(mii->mii_media_active) & IFM_ETH_RXPAUSE) != 0)
                        reg |= MAC_CFG_RX_FC;
        }
        CSR_WRITE_4(sc, ALC_MAC_CFG, reg);
}

static void
alc_stats_clear(struct alc_softc *sc)
{
        struct smb sb, *smb;
        uint32_t *reg;
        int i;

        if ((sc->alc_flags & ALC_FLAG_SMB_BUG) == 0) {
                bus_dmamap_sync(sc->alc_cdata.alc_smb_tag,
                    sc->alc_cdata.alc_smb_map,
                    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
                smb = sc->alc_rdata.alc_smb;
                /* Update done, clear. */
                smb->updated = 0;
                bus_dmamap_sync(sc->alc_cdata.alc_smb_tag,
                    sc->alc_cdata.alc_smb_map,
                    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
        } else {
                for (reg = &sb.rx_frames, i = 0; reg <= &sb.rx_pkts_filtered;
                    reg++) {
                        CSR_READ_4(sc, ALC_RX_MIB_BASE + i);
                        i += sizeof(uint32_t);
                }
                /* Read Tx statistics. */
                for (reg = &sb.tx_frames, i = 0; reg <= &sb.tx_mcast_bytes;
                    reg++) {
                        CSR_READ_4(sc, ALC_TX_MIB_BASE + i);
                        i += sizeof(uint32_t);
                }
        }
}

static void
alc_stats_update(struct alc_softc *sc)
{
        struct alc_hw_stats *stat;
        struct smb sb, *smb;
        if_t ifp;
        uint32_t *reg;
        int i;

        ALC_LOCK_ASSERT(sc);

        ifp = sc->alc_ifp;
        stat = &sc->alc_stats;
        if ((sc->alc_flags & ALC_FLAG_SMB_BUG) == 0) {
                bus_dmamap_sync(sc->alc_cdata.alc_smb_tag,
                    sc->alc_cdata.alc_smb_map,
                    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
                smb = sc->alc_rdata.alc_smb;
                if (smb->updated == 0)
                        return;
        } else {
                smb = &sb;
                /* Read Rx statistics. */
                for (reg = &sb.rx_frames, i = 0; reg <= &sb.rx_pkts_filtered;
                    reg++) {
                        *reg = CSR_READ_4(sc, ALC_RX_MIB_BASE + i);
                        i += sizeof(uint32_t);
                }
                /* Read Tx statistics. */
                for (reg = &sb.tx_frames, i = 0; reg <= &sb.tx_mcast_bytes;
                    reg++) {
                        *reg = CSR_READ_4(sc, ALC_TX_MIB_BASE + i);
                        i += sizeof(uint32_t);
                }
        }

        /* Rx stats. */
        stat->rx_frames += smb->rx_frames;
        stat->rx_bcast_frames += smb->rx_bcast_frames;
        stat->rx_mcast_frames += smb->rx_mcast_frames;
        stat->rx_pause_frames += smb->rx_pause_frames;
        stat->rx_control_frames += smb->rx_control_frames;
        stat->rx_crcerrs += smb->rx_crcerrs;
        stat->rx_lenerrs += smb->rx_lenerrs;
        stat->rx_bytes += smb->rx_bytes;
        stat->rx_runts += smb->rx_runts;
        stat->rx_fragments += smb->rx_fragments;
        stat->rx_pkts_64 += smb->rx_pkts_64;
        stat->rx_pkts_65_127 += smb->rx_pkts_65_127;
        stat->rx_pkts_128_255 += smb->rx_pkts_128_255;
        stat->rx_pkts_256_511 += smb->rx_pkts_256_511;
        stat->rx_pkts_512_1023 += smb->rx_pkts_512_1023;
        stat->rx_pkts_1024_1518 += smb->rx_pkts_1024_1518;
        stat->rx_pkts_1519_max += smb->rx_pkts_1519_max;
        stat->rx_pkts_truncated += smb->rx_pkts_truncated;
        stat->rx_fifo_oflows += smb->rx_fifo_oflows;
        stat->rx_rrs_errs += smb->rx_rrs_errs;
        stat->rx_alignerrs += smb->rx_alignerrs;
        stat->rx_bcast_bytes += smb->rx_bcast_bytes;
        stat->rx_mcast_bytes += smb->rx_mcast_bytes;
        stat->rx_pkts_filtered += smb->rx_pkts_filtered;

        /* Tx stats. */
        stat->tx_frames += smb->tx_frames;
        stat->tx_bcast_frames += smb->tx_bcast_frames;
        stat->tx_mcast_frames += smb->tx_mcast_frames;
        stat->tx_pause_frames += smb->tx_pause_frames;
        stat->tx_excess_defer += smb->tx_excess_defer;
        stat->tx_control_frames += smb->tx_control_frames;
        stat->tx_deferred += smb->tx_deferred;
        stat->tx_bytes += smb->tx_bytes;
        stat->tx_pkts_64 += smb->tx_pkts_64;
        stat->tx_pkts_65_127 += smb->tx_pkts_65_127;
        stat->tx_pkts_128_255 += smb->tx_pkts_128_255;
        stat->tx_pkts_256_511 += smb->tx_pkts_256_511;
        stat->tx_pkts_512_1023 += smb->tx_pkts_512_1023;
        stat->tx_pkts_1024_1518 += smb->tx_pkts_1024_1518;
        stat->tx_pkts_1519_max += smb->tx_pkts_1519_max;
        stat->tx_single_colls += smb->tx_single_colls;
        stat->tx_multi_colls += smb->tx_multi_colls;
        stat->tx_late_colls += smb->tx_late_colls;
        stat->tx_excess_colls += smb->tx_excess_colls;
        stat->tx_underrun += smb->tx_underrun;
        stat->tx_desc_underrun += smb->tx_desc_underrun;
        stat->tx_lenerrs += smb->tx_lenerrs;
        stat->tx_pkts_truncated += smb->tx_pkts_truncated;
        stat->tx_bcast_bytes += smb->tx_bcast_bytes;
        stat->tx_mcast_bytes += smb->tx_mcast_bytes;

        /* Update counters in ifnet. */
        if_inc_counter(ifp, IFCOUNTER_OPACKETS, smb->tx_frames);

        if_inc_counter(ifp, IFCOUNTER_COLLISIONS, smb->tx_single_colls +
            smb->tx_multi_colls * 2 + smb->tx_late_colls +
            smb->tx_excess_colls * HDPX_CFG_RETRY_DEFAULT);

        if_inc_counter(ifp, IFCOUNTER_OERRORS, smb->tx_late_colls +
            smb->tx_excess_colls + smb->tx_underrun + smb->tx_pkts_truncated);

        if_inc_counter(ifp, IFCOUNTER_IPACKETS, smb->rx_frames);

        if_inc_counter(ifp, IFCOUNTER_IERRORS,
            smb->rx_crcerrs + smb->rx_lenerrs +
            smb->rx_runts + smb->rx_pkts_truncated +
            smb->rx_fifo_oflows + smb->rx_rrs_errs +
            smb->rx_alignerrs);

        if ((sc->alc_flags & ALC_FLAG_SMB_BUG) == 0) {
                /* Update done, clear. */
                smb->updated = 0;
                bus_dmamap_sync(sc->alc_cdata.alc_smb_tag,
                    sc->alc_cdata.alc_smb_map,
                    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
        }
}

static int
alc_intr(void *arg)
{
        struct alc_softc *sc;
        uint32_t status;

        sc = (struct alc_softc *)arg;

        if (sc->alc_flags & ALC_FLAG_MT) {
                taskqueue_enqueue(sc->alc_tq, &sc->alc_int_task);
                return (FILTER_HANDLED);
        }

        status = CSR_READ_4(sc, ALC_INTR_STATUS);
        if ((status & ALC_INTRS) == 0)
                return (FILTER_STRAY);
        /* Disable interrupts. */
        CSR_WRITE_4(sc, ALC_INTR_STATUS, INTR_DIS_INT);
        taskqueue_enqueue(sc->alc_tq, &sc->alc_int_task);

        return (FILTER_HANDLED);
}

static void
alc_int_task(void *arg, int pending)
{
        struct alc_softc *sc;
        if_t ifp;
        uint32_t status;
        int more;

        sc = (struct alc_softc *)arg;
        ifp = sc->alc_ifp;

        status = CSR_READ_4(sc, ALC_INTR_STATUS);
        ALC_LOCK(sc);
        if (sc->alc_morework != 0) {
                sc->alc_morework = 0;
                status |= INTR_RX_PKT;
        }
        if ((status & ALC_INTRS) == 0)
                goto done;

        /* Acknowledge interrupts but still disable interrupts. */
        CSR_WRITE_4(sc, ALC_INTR_STATUS, status | INTR_DIS_INT);

        more = 0;
        if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0) {
                if ((status & INTR_RX_PKT) != 0) {
                        more = alc_rxintr(sc, sc->alc_process_limit);
                        if (more == EAGAIN)
                                sc->alc_morework = 1;
                        else if (more == EIO) {
                                if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
                                alc_init_locked(sc);
                                ALC_UNLOCK(sc);
                                return;
                        }
                }
                if ((status & (INTR_DMA_RD_TO_RST | INTR_DMA_WR_TO_RST |
                    INTR_TXQ_TO_RST)) != 0) {
                        if ((status & INTR_DMA_RD_TO_RST) != 0)
                                device_printf(sc->alc_dev,
                                    "DMA read error! -- resetting\n");
                        if ((status & INTR_DMA_WR_TO_RST) != 0)
                                device_printf(sc->alc_dev,
                                    "DMA write error! -- resetting\n");
                        if ((status & INTR_TXQ_TO_RST) != 0)
                                device_printf(sc->alc_dev,
                                    "TxQ reset! -- resetting\n");
                        if_setdrvflagbits(ifp, 0, IFF_DRV_RUNNING);
                        alc_init_locked(sc);
                        ALC_UNLOCK(sc);
                        return;
                }
                if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0 &&
                    !if_sendq_empty(ifp))
                        alc_start_locked(ifp);
        }

        if (more == EAGAIN ||
            (CSR_READ_4(sc, ALC_INTR_STATUS) & ALC_INTRS) != 0) {
                ALC_UNLOCK(sc);
                taskqueue_enqueue(sc->alc_tq, &sc->alc_int_task);
                return;
        }

done:
        if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0) {
                /* Re-enable interrupts if we're running. */
                if (sc->alc_flags & ALC_FLAG_MT)
                        CSR_WRITE_4(sc, ALC_INTR_STATUS, 0);
                else
                        CSR_WRITE_4(sc, ALC_INTR_STATUS, 0x7FFFFFFF);
        }
        ALC_UNLOCK(sc);
}

static void
alc_txeof(struct alc_softc *sc)
{
        if_t ifp;
        struct alc_txdesc *txd;
        uint32_t cons, prod;

        ALC_LOCK_ASSERT(sc);

        ifp = sc->alc_ifp;

        if (sc->alc_cdata.alc_tx_cnt == 0)
                return;
        bus_dmamap_sync(sc->alc_cdata.alc_tx_ring_tag,
            sc->alc_cdata.alc_tx_ring_map, BUS_DMASYNC_POSTWRITE);
        if ((sc->alc_flags & ALC_FLAG_CMB_BUG) == 0) {
                bus_dmamap_sync(sc->alc_cdata.alc_cmb_tag,
                    sc->alc_cdata.alc_cmb_map, BUS_DMASYNC_POSTREAD);
                prod = sc->alc_rdata.alc_cmb->cons;
        } else {
                if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0)
                        prod = CSR_READ_2(sc, ALC_MBOX_TD_PRI0_CONS_IDX);
                else {
                        prod = CSR_READ_4(sc, ALC_MBOX_TD_CONS_IDX);
                        /* Assume we're using normal Tx priority queue. */
                        prod = (prod & MBOX_TD_CONS_LO_IDX_MASK) >>
                            MBOX_TD_CONS_LO_IDX_SHIFT;
                }
        }
        cons = sc->alc_cdata.alc_tx_cons;
        /*
         * Go through our Tx list and free mbufs for those
         * frames which have been transmitted.
         */
        for (; cons != prod; ALC_DESC_INC(cons, ALC_TX_RING_CNT)) {
                if (sc->alc_cdata.alc_tx_cnt <= 0)
                        break;
                if_setdrvflagbits(ifp, 0, IFF_DRV_OACTIVE);
                sc->alc_cdata.alc_tx_cnt--;
                txd = &sc->alc_cdata.alc_txdesc[cons];
                if (txd->tx_m != NULL) {
                        /* Reclaim transmitted mbufs. */
                        bus_dmamap_sync(sc->alc_cdata.alc_tx_tag,
                            txd->tx_dmamap, BUS_DMASYNC_POSTWRITE);
                        bus_dmamap_unload(sc->alc_cdata.alc_tx_tag,
                            txd->tx_dmamap);
                        m_freem(txd->tx_m);
                        txd->tx_m = NULL;
                }
        }

        if ((sc->alc_flags & ALC_FLAG_CMB_BUG) == 0)
                bus_dmamap_sync(sc->alc_cdata.alc_cmb_tag,
                    sc->alc_cdata.alc_cmb_map, BUS_DMASYNC_PREREAD);
        sc->alc_cdata.alc_tx_cons = cons;
        /*
         * Unarm watchdog timer only when there is no pending
         * frames in Tx queue.
         */
        if (sc->alc_cdata.alc_tx_cnt == 0)
                sc->alc_watchdog_timer = 0;
}

static int
alc_newbuf(struct alc_softc *sc, struct alc_rxdesc *rxd)
{
        struct mbuf *m;
        bus_dma_segment_t segs[1];
        bus_dmamap_t map;
        int nsegs;

        m = m_getcl(M_NOWAIT, MT_DATA, M_PKTHDR);
        if (m == NULL)
                return (ENOBUFS);
        m->m_len = m->m_pkthdr.len = RX_BUF_SIZE_MAX;
#ifndef __NO_STRICT_ALIGNMENT
        m_adj(m, sizeof(uint64_t));
#endif

        if (bus_dmamap_load_mbuf_sg(sc->alc_cdata.alc_rx_tag,
            sc->alc_cdata.alc_rx_sparemap, m, segs, &nsegs, 0) != 0) {
                m_freem(m);
                return (ENOBUFS);
        }
        KASSERT(nsegs == 1, ("%s: %d segments returned!", __func__, nsegs));

        if (rxd->rx_m != NULL) {
                bus_dmamap_sync(sc->alc_cdata.alc_rx_tag, rxd->rx_dmamap,
                    BUS_DMASYNC_POSTREAD);
                bus_dmamap_unload(sc->alc_cdata.alc_rx_tag, rxd->rx_dmamap);
        }
        map = rxd->rx_dmamap;
        rxd->rx_dmamap = sc->alc_cdata.alc_rx_sparemap;
        sc->alc_cdata.alc_rx_sparemap = map;
        bus_dmamap_sync(sc->alc_cdata.alc_rx_tag, rxd->rx_dmamap,
            BUS_DMASYNC_PREREAD);
        rxd->rx_m = m;
        rxd->rx_desc->addr = htole64(segs[0].ds_addr);
        return (0);
}

static int
alc_rxintr(struct alc_softc *sc, int count)
{
        if_t ifp;
        struct rx_rdesc *rrd;
        uint32_t nsegs, status;
        int rr_cons, prog;

        bus_dmamap_sync(sc->alc_cdata.alc_rr_ring_tag,
            sc->alc_cdata.alc_rr_ring_map,
            BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
        bus_dmamap_sync(sc->alc_cdata.alc_rx_ring_tag,
            sc->alc_cdata.alc_rx_ring_map, BUS_DMASYNC_POSTWRITE);
        rr_cons = sc->alc_cdata.alc_rr_cons;
        ifp = sc->alc_ifp;
        for (prog = 0; (if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0;) {
                if (count-- <= 0)
                        break;
                rrd = &sc->alc_rdata.alc_rr_ring[rr_cons];
                status = le32toh(rrd->status);
                if ((status & RRD_VALID) == 0)
                        break;
                nsegs = RRD_RD_CNT(le32toh(rrd->rdinfo));
                if (nsegs == 0) {
                        /* This should not happen! */
                        device_printf(sc->alc_dev,
                            "unexpected segment count -- resetting\n");
                        return (EIO);
                }
                alc_rxeof(sc, rrd);
                /* Clear Rx return status. */
                rrd->status = 0;
                ALC_DESC_INC(rr_cons, ALC_RR_RING_CNT);
                sc->alc_cdata.alc_rx_cons += nsegs;
                sc->alc_cdata.alc_rx_cons %= ALC_RR_RING_CNT;
                prog += nsegs;
        }

        if (prog > 0) {
                /* Update the consumer index. */
                sc->alc_cdata.alc_rr_cons = rr_cons;
                /* Sync Rx return descriptors. */
                bus_dmamap_sync(sc->alc_cdata.alc_rr_ring_tag,
                    sc->alc_cdata.alc_rr_ring_map,
                    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
                /*
                 * Sync updated Rx descriptors such that controller see
                 * modified buffer addresses.
                 */
                bus_dmamap_sync(sc->alc_cdata.alc_rx_ring_tag,
                    sc->alc_cdata.alc_rx_ring_map, BUS_DMASYNC_PREWRITE);
                /*
                 * Let controller know availability of new Rx buffers.
                 * Since alc(4) use RXQ_CFG_RD_BURST_DEFAULT descriptors
                 * it may be possible to update ALC_MBOX_RD0_PROD_IDX
                 * only when Rx buffer pre-fetching is required. In
                 * addition we already set ALC_RX_RD_FREE_THRESH to
                 * RX_RD_FREE_THRESH_LO_DEFAULT descriptors. However
                 * it still seems that pre-fetching needs more
                 * experimentation.
                 */
                if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0)
                        CSR_WRITE_2(sc, ALC_MBOX_RD0_PROD_IDX,
                            (uint16_t)sc->alc_cdata.alc_rx_cons);
                else
                        CSR_WRITE_4(sc, ALC_MBOX_RD0_PROD_IDX,
                            sc->alc_cdata.alc_rx_cons);
        }

        return (count > 0 ? 0 : EAGAIN);
}

#ifndef __NO_STRICT_ALIGNMENT
static struct mbuf *
alc_fixup_rx(if_t ifp, struct mbuf *m)
{
        struct mbuf *n;
        int i;
        uint16_t *src, *dst;

        src = mtod(m, uint16_t *);
        dst = src - 3;

        if (m->m_next == NULL) {
                for (i = 0; i < (m->m_len / sizeof(uint16_t) + 1); i++)
                        *dst++ = *src++;
                m->m_data -= 6;
                return (m);
        }
        /*
         * Append a new mbuf to received mbuf chain and copy ethernet
         * header from the mbuf chain. This can save lots of CPU
         * cycles for jumbo frame.
         */
        MGETHDR(n, M_NOWAIT, MT_DATA);
        if (n == NULL) {
                if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
                m_freem(m);
                return (NULL);
        }
        bcopy(m->m_data, n->m_data, ETHER_HDR_LEN);
        m->m_data += ETHER_HDR_LEN;
        m->m_len -= ETHER_HDR_LEN;
        n->m_len = ETHER_HDR_LEN;
        M_MOVE_PKTHDR(n, m);
        n->m_next = m;
        return (n);
}
#endif

/* Receive a frame. */
static void
alc_rxeof(struct alc_softc *sc, struct rx_rdesc *rrd)
{
        struct alc_rxdesc *rxd;
        if_t ifp;
        struct mbuf *mp, *m;
        uint32_t rdinfo, status, vtag;
        int count, nsegs, rx_cons;

        ifp = sc->alc_ifp;
        status = le32toh(rrd->status);
        rdinfo = le32toh(rrd->rdinfo);
        rx_cons = RRD_RD_IDX(rdinfo);
        nsegs = RRD_RD_CNT(rdinfo);

        sc->alc_cdata.alc_rxlen = RRD_BYTES(status);
        if ((status & (RRD_ERR_SUM | RRD_ERR_LENGTH)) != 0) {
                /*
                 * We want to pass the following frames to upper
                 * layer regardless of error status of Rx return
                 * ring.
                 *
                 *  o IP/TCP/UDP checksum is bad.
                 *  o frame length and protocol specific length
                 *     does not match.
                 *
                 *  Force network stack compute checksum for
                 *  errored frames.
                 */
                status |= RRD_TCP_UDPCSUM_NOK | RRD_IPCSUM_NOK;
                if ((status & (RRD_ERR_CRC | RRD_ERR_ALIGN |
                    RRD_ERR_TRUNC | RRD_ERR_RUNT)) != 0)
                        return;
        }

        for (count = 0; count < nsegs; count++,
            ALC_DESC_INC(rx_cons, ALC_RX_RING_CNT)) {
                rxd = &sc->alc_cdata.alc_rxdesc[rx_cons];
                mp = rxd->rx_m;
                /* Add a new receive buffer to the ring. */
                if (alc_newbuf(sc, rxd) != 0) {
                        if_inc_counter(ifp, IFCOUNTER_IQDROPS, 1);
                        /* Reuse Rx buffers. */
                        if (sc->alc_cdata.alc_rxhead != NULL)
                                m_freem(sc->alc_cdata.alc_rxhead);
                        break;
                }

                /*
                 * Assume we've received a full sized frame.
                 * Actual size is fixed when we encounter the end of
                 * multi-segmented frame.
                 */
                mp->m_len = sc->alc_buf_size;

                /* Chain received mbufs. */
                if (sc->alc_cdata.alc_rxhead == NULL) {
                        sc->alc_cdata.alc_rxhead = mp;
                        sc->alc_cdata.alc_rxtail = mp;
                } else {
                        mp->m_flags &= ~M_PKTHDR;
                        sc->alc_cdata.alc_rxprev_tail =
                            sc->alc_cdata.alc_rxtail;
                        sc->alc_cdata.alc_rxtail->m_next = mp;
                        sc->alc_cdata.alc_rxtail = mp;
                }

                if (count == nsegs - 1) {
                        /* Last desc. for this frame. */
                        m = sc->alc_cdata.alc_rxhead;
                        m->m_flags |= M_PKTHDR;
                        /*
                         * It seems that L1C/L2C controller has no way
                         * to tell hardware to strip CRC bytes.
                         */
                        m->m_pkthdr.len =
                            sc->alc_cdata.alc_rxlen - ETHER_CRC_LEN;
                        if (nsegs > 1) {
                                /* Set last mbuf size. */
                                mp->m_len = sc->alc_cdata.alc_rxlen -
                                    (nsegs - 1) * sc->alc_buf_size;
                                /* Remove the CRC bytes in chained mbufs. */
                                if (mp->m_len <= ETHER_CRC_LEN) {
                                        sc->alc_cdata.alc_rxtail =
                                            sc->alc_cdata.alc_rxprev_tail;
                                        sc->alc_cdata.alc_rxtail->m_len -=
                                            (ETHER_CRC_LEN - mp->m_len);
                                        sc->alc_cdata.alc_rxtail->m_next = NULL;
                                        m_freem(mp);
                                } else {
                                        mp->m_len -= ETHER_CRC_LEN;
                                }
                        } else
                                m->m_len = m->m_pkthdr.len;
                        m->m_pkthdr.rcvif = ifp;
                        /*
                         * Due to hardware bugs, Rx checksum offloading
                         * was intentionally disabled.
                         */
                        if ((if_getcapenable(ifp) & IFCAP_VLAN_HWTAGGING) != 0 &&
                            (status & RRD_VLAN_TAG) != 0) {
                                vtag = RRD_VLAN(le32toh(rrd->vtag));
                                m->m_pkthdr.ether_vtag = ntohs(vtag);
                                m->m_flags |= M_VLANTAG;
                        }
#ifndef __NO_STRICT_ALIGNMENT
                        m = alc_fixup_rx(ifp, m);
                        if (m != NULL)
#endif
                        {
                        /* Pass it on. */
                        ALC_UNLOCK(sc);
                        if_input(ifp, m);
                        ALC_LOCK(sc);
                        }
                }
        }
        /* Reset mbuf chains. */
        ALC_RXCHAIN_RESET(sc);
}

static void
alc_tick(void *arg)
{
        struct alc_softc *sc;
        struct mii_data *mii;

        sc = (struct alc_softc *)arg;

        ALC_LOCK_ASSERT(sc);

        mii = device_get_softc(sc->alc_miibus);
        mii_tick(mii);
        alc_stats_update(sc);
        /*
         * alc(4) does not rely on Tx completion interrupts to reclaim
         * transferred buffers. Instead Tx completion interrupts are
         * used to hint for scheduling Tx task. So it's necessary to
         * release transmitted buffers by kicking Tx completion
         * handler. This limits the maximum reclamation delay to a hz.
         */
        alc_txeof(sc);
        alc_watchdog(sc);
        callout_reset(&sc->alc_tick_ch, hz, alc_tick, sc);
}

static void
alc_osc_reset(struct alc_softc *sc)
{
        uint32_t reg;

        reg = CSR_READ_4(sc, ALC_MISC3);
        reg &= ~MISC3_25M_BY_SW;
        reg |= MISC3_25M_NOTO_INTNL;
        CSR_WRITE_4(sc, ALC_MISC3, reg);

        reg = CSR_READ_4(sc, ALC_MISC);
        if (AR816X_REV(sc->alc_rev) >= AR816X_REV_B0) {
                /*
                 * Restore over-current protection default value.
                 * This value could be reset by MAC reset.
                 */
                reg &= ~MISC_PSW_OCP_MASK;
                reg |= (MISC_PSW_OCP_DEFAULT << MISC_PSW_OCP_SHIFT);
                reg &= ~MISC_INTNLOSC_OPEN;
                CSR_WRITE_4(sc, ALC_MISC, reg);
                CSR_WRITE_4(sc, ALC_MISC, reg | MISC_INTNLOSC_OPEN);
                reg = CSR_READ_4(sc, ALC_MISC2);
                reg &= ~MISC2_CALB_START;
                CSR_WRITE_4(sc, ALC_MISC2, reg);
                CSR_WRITE_4(sc, ALC_MISC2, reg | MISC2_CALB_START);

        } else {
                reg &= ~MISC_INTNLOSC_OPEN;
                /* Disable isolate for revision A devices. */
                if (AR816X_REV(sc->alc_rev) <= AR816X_REV_A1)
                        reg &= ~MISC_ISO_ENB;
                CSR_WRITE_4(sc, ALC_MISC, reg | MISC_INTNLOSC_OPEN);
                CSR_WRITE_4(sc, ALC_MISC, reg);
        }

        DELAY(20);
}

static void
alc_reset(struct alc_softc *sc)
{
        uint32_t pmcfg, reg;
        int i;

        pmcfg = 0;
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0) {
                /* Reset workaround. */
                CSR_WRITE_4(sc, ALC_MBOX_RD0_PROD_IDX, 1);
                if (AR816X_REV(sc->alc_rev) <= AR816X_REV_A1 &&
                    (sc->alc_rev & 0x01) != 0) {
                        /* Disable L0s/L1s before reset. */
                        pmcfg = CSR_READ_4(sc, ALC_PM_CFG);
                        if ((pmcfg & (PM_CFG_ASPM_L0S_ENB | PM_CFG_ASPM_L1_ENB))
                            != 0) {
                                pmcfg &= ~(PM_CFG_ASPM_L0S_ENB |
                                    PM_CFG_ASPM_L1_ENB);
                                CSR_WRITE_4(sc, ALC_PM_CFG, pmcfg);
                        }
                }
        }
        reg = CSR_READ_4(sc, ALC_MASTER_CFG);
        reg |= MASTER_OOB_DIS_OFF | MASTER_RESET;
        CSR_WRITE_4(sc, ALC_MASTER_CFG, reg);

        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0) {
                for (i = ALC_RESET_TIMEOUT; i > 0; i--) {
                        DELAY(10);
                        if (CSR_READ_4(sc, ALC_MBOX_RD0_PROD_IDX) == 0)
                                break;
                }
                if (i == 0)
                        device_printf(sc->alc_dev, "MAC reset timeout!\n");
        }
        for (i = ALC_RESET_TIMEOUT; i > 0; i--) {
                DELAY(10);
                if ((CSR_READ_4(sc, ALC_MASTER_CFG) & MASTER_RESET) == 0)
                        break;
        }
        if (i == 0)
                device_printf(sc->alc_dev, "master reset timeout!\n");

        for (i = ALC_RESET_TIMEOUT; i > 0; i--) {
                reg = CSR_READ_4(sc, ALC_IDLE_STATUS);
                if ((reg & (IDLE_STATUS_RXMAC | IDLE_STATUS_TXMAC |
                    IDLE_STATUS_RXQ | IDLE_STATUS_TXQ)) == 0)
                        break;
                DELAY(10);
        }
        if (i == 0)
                device_printf(sc->alc_dev, "reset timeout(0x%08x)!\n", reg);

        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0) {
                if (AR816X_REV(sc->alc_rev) <= AR816X_REV_A1 &&
                    (sc->alc_rev & 0x01) != 0) {
                        reg = CSR_READ_4(sc, ALC_MASTER_CFG);
                        reg |= MASTER_CLK_SEL_DIS;
                        CSR_WRITE_4(sc, ALC_MASTER_CFG, reg);
                        /* Restore L0s/L1s config. */
                        if ((pmcfg & (PM_CFG_ASPM_L0S_ENB | PM_CFG_ASPM_L1_ENB))
                            != 0)
                                CSR_WRITE_4(sc, ALC_PM_CFG, pmcfg);
                }

                alc_osc_reset(sc);
                reg = CSR_READ_4(sc, ALC_MISC3);
                reg &= ~MISC3_25M_BY_SW;
                reg |= MISC3_25M_NOTO_INTNL;
                CSR_WRITE_4(sc, ALC_MISC3, reg);
                reg = CSR_READ_4(sc, ALC_MISC);
                reg &= ~MISC_INTNLOSC_OPEN;
                if (AR816X_REV(sc->alc_rev) <= AR816X_REV_A1)
                        reg &= ~MISC_ISO_ENB;
                CSR_WRITE_4(sc, ALC_MISC, reg);
                DELAY(20);
        }
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0 ||
            sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8152_B ||
            sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8151_V2)
                CSR_WRITE_4(sc, ALC_SERDES_LOCK,
                    CSR_READ_4(sc, ALC_SERDES_LOCK) | SERDES_MAC_CLK_SLOWDOWN |
                    SERDES_PHY_CLK_SLOWDOWN);
}

static void
alc_init(void *xsc)
{
        struct alc_softc *sc;

        sc = (struct alc_softc *)xsc;
        ALC_LOCK(sc);
        alc_init_locked(sc);
        ALC_UNLOCK(sc);
}

static void
alc_init_locked(struct alc_softc *sc)
{
        if_t ifp;
        uint8_t eaddr[ETHER_ADDR_LEN];
        bus_addr_t paddr;
        uint32_t reg, rxf_hi, rxf_lo;

        ALC_LOCK_ASSERT(sc);

        ifp = sc->alc_ifp;

        if ((if_getdrvflags(ifp) & IFF_DRV_RUNNING) != 0)
                return;
        /*
         * Cancel any pending I/O.
         */
        alc_stop(sc);
        /*
         * Reset the chip to a known state.
         */
        alc_reset(sc);

        /* Initialize Rx descriptors. */
        if (alc_init_rx_ring(sc) != 0) {
                device_printf(sc->alc_dev, "no memory for Rx buffers.\n");
                alc_stop(sc);
                return;
        }
        alc_init_rr_ring(sc);
        alc_init_tx_ring(sc);
        alc_init_cmb(sc);
        alc_init_smb(sc);

        /* Enable all clocks. */
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0) {
                CSR_WRITE_4(sc, ALC_CLK_GATING_CFG, CLK_GATING_DMAW_ENB |
                    CLK_GATING_DMAR_ENB | CLK_GATING_TXQ_ENB |
                    CLK_GATING_RXQ_ENB | CLK_GATING_TXMAC_ENB |
                    CLK_GATING_RXMAC_ENB);
                if (AR816X_REV(sc->alc_rev) >= AR816X_REV_B0)
                        CSR_WRITE_4(sc, ALC_IDLE_DECISN_TIMER,
                            IDLE_DECISN_TIMER_DEFAULT_1MS);
        } else
                CSR_WRITE_4(sc, ALC_CLK_GATING_CFG, 0);

        /* Reprogram the station address. */
        bcopy(if_getlladdr(ifp), eaddr, ETHER_ADDR_LEN);
        CSR_WRITE_4(sc, ALC_PAR0,
            eaddr[2] << 24 | eaddr[3] << 16 | eaddr[4] << 8 | eaddr[5]);
        CSR_WRITE_4(sc, ALC_PAR1, eaddr[0] << 8 | eaddr[1]);
        /*
         * Clear WOL status and disable all WOL feature as WOL
         * would interfere Rx operation under normal environments.
         */
        CSR_READ_4(sc, ALC_WOL_CFG);
        CSR_WRITE_4(sc, ALC_WOL_CFG, 0);
        /* Set Tx descriptor base addresses. */
        paddr = sc->alc_rdata.alc_tx_ring_paddr;
        CSR_WRITE_4(sc, ALC_TX_BASE_ADDR_HI, ALC_ADDR_HI(paddr));
        CSR_WRITE_4(sc, ALC_TDL_HEAD_ADDR_LO, ALC_ADDR_LO(paddr));
        /* We don't use high priority ring. */
        CSR_WRITE_4(sc, ALC_TDH_HEAD_ADDR_LO, 0);
        /* Set Tx descriptor counter. */
        CSR_WRITE_4(sc, ALC_TD_RING_CNT,
            (ALC_TX_RING_CNT << TD_RING_CNT_SHIFT) & TD_RING_CNT_MASK);
        /* Set Rx descriptor base addresses. */
        paddr = sc->alc_rdata.alc_rx_ring_paddr;
        CSR_WRITE_4(sc, ALC_RX_BASE_ADDR_HI, ALC_ADDR_HI(paddr));
        CSR_WRITE_4(sc, ALC_RD0_HEAD_ADDR_LO, ALC_ADDR_LO(paddr));
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) == 0) {
                /* We use one Rx ring. */
                CSR_WRITE_4(sc, ALC_RD1_HEAD_ADDR_LO, 0);
                CSR_WRITE_4(sc, ALC_RD2_HEAD_ADDR_LO, 0);
                CSR_WRITE_4(sc, ALC_RD3_HEAD_ADDR_LO, 0);
        }
        /* Set Rx descriptor counter. */
        CSR_WRITE_4(sc, ALC_RD_RING_CNT,
            (ALC_RX_RING_CNT << RD_RING_CNT_SHIFT) & RD_RING_CNT_MASK);

        /*
         * Let hardware split jumbo frames into alc_max_buf_sized chunks.
         * if it do not fit the buffer size. Rx return descriptor holds
         * a counter that indicates how many fragments were made by the
         * hardware. The buffer size should be multiple of 8 bytes.
         * Since hardware has limit on the size of buffer size, always
         * use the maximum value.
         * For strict-alignment architectures make sure to reduce buffer
         * size by 8 bytes to make room for alignment fixup.
         */
#ifndef __NO_STRICT_ALIGNMENT
        sc->alc_buf_size = RX_BUF_SIZE_MAX - sizeof(uint64_t);
#else
        sc->alc_buf_size = RX_BUF_SIZE_MAX;
#endif
        CSR_WRITE_4(sc, ALC_RX_BUF_SIZE, sc->alc_buf_size);

        paddr = sc->alc_rdata.alc_rr_ring_paddr;
        /* Set Rx return descriptor base addresses. */
        CSR_WRITE_4(sc, ALC_RRD0_HEAD_ADDR_LO, ALC_ADDR_LO(paddr));
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) == 0) {
                /* We use one Rx return ring. */
                CSR_WRITE_4(sc, ALC_RRD1_HEAD_ADDR_LO, 0);
                CSR_WRITE_4(sc, ALC_RRD2_HEAD_ADDR_LO, 0);
                CSR_WRITE_4(sc, ALC_RRD3_HEAD_ADDR_LO, 0);
        }
        /* Set Rx return descriptor counter. */
        CSR_WRITE_4(sc, ALC_RRD_RING_CNT,
            (ALC_RR_RING_CNT << RRD_RING_CNT_SHIFT) & RRD_RING_CNT_MASK);
        paddr = sc->alc_rdata.alc_cmb_paddr;
        CSR_WRITE_4(sc, ALC_CMB_BASE_ADDR_LO, ALC_ADDR_LO(paddr));
        paddr = sc->alc_rdata.alc_smb_paddr;
        CSR_WRITE_4(sc, ALC_SMB_BASE_ADDR_HI, ALC_ADDR_HI(paddr));
        CSR_WRITE_4(sc, ALC_SMB_BASE_ADDR_LO, ALC_ADDR_LO(paddr));

        if (sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8152_B) {
                /* Reconfigure SRAM - Vendor magic. */
                CSR_WRITE_4(sc, ALC_SRAM_RX_FIFO_LEN, 0x000002A0);
                CSR_WRITE_4(sc, ALC_SRAM_TX_FIFO_LEN, 0x00000100);
                CSR_WRITE_4(sc, ALC_SRAM_RX_FIFO_ADDR, 0x029F0000);
                CSR_WRITE_4(sc, ALC_SRAM_RD0_ADDR, 0x02BF02A0);
                CSR_WRITE_4(sc, ALC_SRAM_TX_FIFO_ADDR, 0x03BF02C0);
                CSR_WRITE_4(sc, ALC_SRAM_TD_ADDR, 0x03DF03C0);
                CSR_WRITE_4(sc, ALC_TXF_WATER_MARK, 0x00000000);
                CSR_WRITE_4(sc, ALC_RD_DMA_CFG, 0x00000000);
        }

        /* Tell hardware that we're ready to load DMA blocks. */
        CSR_WRITE_4(sc, ALC_DMA_BLOCK, DMA_BLOCK_LOAD);

        /* Configure interrupt moderation timer. */
        reg = ALC_USECS(sc->alc_int_rx_mod) << IM_TIMER_RX_SHIFT;
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) == 0)
                reg |= ALC_USECS(sc->alc_int_tx_mod) << IM_TIMER_TX_SHIFT;
        CSR_WRITE_4(sc, ALC_IM_TIMER, reg);
        /*
         * We don't want to automatic interrupt clear as task queue
         * for the interrupt should know interrupt status.
         */
        reg = CSR_READ_4(sc, ALC_MASTER_CFG);
        reg &= ~(MASTER_IM_RX_TIMER_ENB | MASTER_IM_TX_TIMER_ENB);
        reg |= MASTER_SA_TIMER_ENB;
        if (ALC_USECS(sc->alc_int_rx_mod) != 0)
                reg |= MASTER_IM_RX_TIMER_ENB;
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) == 0 &&
            ALC_USECS(sc->alc_int_tx_mod) != 0)
                reg |= MASTER_IM_TX_TIMER_ENB;
        CSR_WRITE_4(sc, ALC_MASTER_CFG, reg);
        /*
         * Disable interrupt re-trigger timer. We don't want automatic
         * re-triggering of un-ACKed interrupts.
         */
        CSR_WRITE_4(sc, ALC_INTR_RETRIG_TIMER, ALC_USECS(0));
        /* Configure CMB. */
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0) {
                CSR_WRITE_4(sc, ALC_CMB_TD_THRESH, ALC_TX_RING_CNT / 3);
                CSR_WRITE_4(sc, ALC_CMB_TX_TIMER,
                    ALC_USECS(sc->alc_int_tx_mod));
        } else {
                if ((sc->alc_flags & ALC_FLAG_CMB_BUG) == 0) {
                        CSR_WRITE_4(sc, ALC_CMB_TD_THRESH, 4);
                        CSR_WRITE_4(sc, ALC_CMB_TX_TIMER, ALC_USECS(5000));
                } else
                        CSR_WRITE_4(sc, ALC_CMB_TX_TIMER, ALC_USECS(0));
        }
        /*
         * Hardware can be configured to issue SMB interrupt based
         * on programmed interval. Since there is a callout that is
         * invoked for every hz in driver we use that instead of
         * relying on periodic SMB interrupt.
         */
        CSR_WRITE_4(sc, ALC_SMB_STAT_TIMER, ALC_USECS(0));
        /* Clear MAC statistics. */
        alc_stats_clear(sc);

        /*
         * Always use maximum frame size that controller can support.
         * Otherwise received frames that has larger frame length
         * than alc(4) MTU would be silently dropped in hardware. This
         * would make path-MTU discovery hard as sender wouldn't get
         * any responses from receiver. alc(4) supports
         * multi-fragmented frames on Rx path so it has no issue on
         * assembling fragmented frames. Using maximum frame size also
         * removes the need to reinitialize hardware when interface
         * MTU configuration was changed.
         *
         * Be conservative in what you do, be liberal in what you
         * accept from others - RFC 793.
         */
        CSR_WRITE_4(sc, ALC_FRAME_SIZE, sc->alc_ident->max_framelen);

        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) == 0) {
                /* Disable header split(?) */
                CSR_WRITE_4(sc, ALC_HDS_CFG, 0);

                /* Configure IPG/IFG parameters. */
                CSR_WRITE_4(sc, ALC_IPG_IFG_CFG,
                    ((IPG_IFG_IPGT_DEFAULT << IPG_IFG_IPGT_SHIFT) &
                    IPG_IFG_IPGT_MASK) |
                    ((IPG_IFG_MIFG_DEFAULT << IPG_IFG_MIFG_SHIFT) &
                    IPG_IFG_MIFG_MASK) |
                    ((IPG_IFG_IPG1_DEFAULT << IPG_IFG_IPG1_SHIFT) &
                    IPG_IFG_IPG1_MASK) |
                    ((IPG_IFG_IPG2_DEFAULT << IPG_IFG_IPG2_SHIFT) &
                    IPG_IFG_IPG2_MASK));
                /* Set parameters for half-duplex media. */
                CSR_WRITE_4(sc, ALC_HDPX_CFG,
                    ((HDPX_CFG_LCOL_DEFAULT << HDPX_CFG_LCOL_SHIFT) &
                    HDPX_CFG_LCOL_MASK) |
                    ((HDPX_CFG_RETRY_DEFAULT << HDPX_CFG_RETRY_SHIFT) &
                    HDPX_CFG_RETRY_MASK) | HDPX_CFG_EXC_DEF_EN |
                    ((HDPX_CFG_ABEBT_DEFAULT << HDPX_CFG_ABEBT_SHIFT) &
                    HDPX_CFG_ABEBT_MASK) |
                    ((HDPX_CFG_JAMIPG_DEFAULT << HDPX_CFG_JAMIPG_SHIFT) &
                    HDPX_CFG_JAMIPG_MASK));
        }

        /*
         * Set TSO/checksum offload threshold. For frames that is
         * larger than this threshold, hardware wouldn't do
         * TSO/checksum offloading.
         */
        reg = (sc->alc_ident->max_framelen >> TSO_OFFLOAD_THRESH_UNIT_SHIFT) &
            TSO_OFFLOAD_THRESH_MASK;
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0)
                reg |= TSO_OFFLOAD_ERRLGPKT_DROP_ENB;
        CSR_WRITE_4(sc, ALC_TSO_OFFLOAD_THRESH, reg);
        /* Configure TxQ. */
        reg = (alc_dma_burst[sc->alc_dma_rd_burst] <<
            TXQ_CFG_TX_FIFO_BURST_SHIFT) & TXQ_CFG_TX_FIFO_BURST_MASK;
        if (sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8152_B ||
            sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8152_B2)
                reg >>= 1;
        reg |= (TXQ_CFG_TD_BURST_DEFAULT << TXQ_CFG_TD_BURST_SHIFT) &
            TXQ_CFG_TD_BURST_MASK;
        reg |= TXQ_CFG_IP_OPTION_ENB | TXQ_CFG_8023_ENB;
        CSR_WRITE_4(sc, ALC_TXQ_CFG, reg | TXQ_CFG_ENHANCED_MODE);
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0) {
                reg = (TXQ_CFG_TD_BURST_DEFAULT << HQTD_CFG_Q1_BURST_SHIFT |
                    TXQ_CFG_TD_BURST_DEFAULT << HQTD_CFG_Q2_BURST_SHIFT |
                    TXQ_CFG_TD_BURST_DEFAULT << HQTD_CFG_Q3_BURST_SHIFT |
                    HQTD_CFG_BURST_ENB);
                CSR_WRITE_4(sc, ALC_HQTD_CFG, reg);
                reg = WRR_PRI_RESTRICT_NONE;
                reg |= (WRR_PRI_DEFAULT << WRR_PRI0_SHIFT |
                    WRR_PRI_DEFAULT << WRR_PRI1_SHIFT |
                    WRR_PRI_DEFAULT << WRR_PRI2_SHIFT |
                    WRR_PRI_DEFAULT << WRR_PRI3_SHIFT);
                CSR_WRITE_4(sc, ALC_WRR, reg);
        } else {
                /* Configure Rx free descriptor pre-fetching. */
                CSR_WRITE_4(sc, ALC_RX_RD_FREE_THRESH,
                    ((RX_RD_FREE_THRESH_HI_DEFAULT <<
                    RX_RD_FREE_THRESH_HI_SHIFT) & RX_RD_FREE_THRESH_HI_MASK) |
                    ((RX_RD_FREE_THRESH_LO_DEFAULT <<
                    RX_RD_FREE_THRESH_LO_SHIFT) & RX_RD_FREE_THRESH_LO_MASK));
        }

        /*
         * Configure flow control parameters.
         * XON  : 80% of Rx FIFO
         * XOFF : 30% of Rx FIFO
         */
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0) {
                reg = CSR_READ_4(sc, ALC_SRAM_RX_FIFO_LEN);
                reg &= SRAM_RX_FIFO_LEN_MASK;
                reg *= 8;
                if (reg > 8 * 1024)
                        reg -= RX_FIFO_PAUSE_816X_RSVD;
                else
                        reg -= RX_BUF_SIZE_MAX;
                reg /= 8;
                CSR_WRITE_4(sc, ALC_RX_FIFO_PAUSE_THRESH,
                    ((reg << RX_FIFO_PAUSE_THRESH_LO_SHIFT) &
                    RX_FIFO_PAUSE_THRESH_LO_MASK) |
                    (((RX_FIFO_PAUSE_816X_RSVD / 8) <<
                    RX_FIFO_PAUSE_THRESH_HI_SHIFT) &
                    RX_FIFO_PAUSE_THRESH_HI_MASK));
        } else if (sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8131 ||
            sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8132) {
                reg = CSR_READ_4(sc, ALC_SRAM_RX_FIFO_LEN);
                rxf_hi = (reg * 8) / 10;
                rxf_lo = (reg * 3) / 10;
                CSR_WRITE_4(sc, ALC_RX_FIFO_PAUSE_THRESH,
                    ((rxf_lo << RX_FIFO_PAUSE_THRESH_LO_SHIFT) &
                     RX_FIFO_PAUSE_THRESH_LO_MASK) |
                    ((rxf_hi << RX_FIFO_PAUSE_THRESH_HI_SHIFT) &
                     RX_FIFO_PAUSE_THRESH_HI_MASK));
        }

        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) == 0) {
                /* Disable RSS until I understand L1C/L2C's RSS logic. */
                CSR_WRITE_4(sc, ALC_RSS_IDT_TABLE0, 0);
                CSR_WRITE_4(sc, ALC_RSS_CPU, 0);
        }

        /* Configure RxQ. */
        reg = (RXQ_CFG_RD_BURST_DEFAULT << RXQ_CFG_RD_BURST_SHIFT) &
            RXQ_CFG_RD_BURST_MASK;
        reg |= RXQ_CFG_RSS_MODE_DIS;
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0) {
                reg |= (RXQ_CFG_816X_IDT_TBL_SIZE_DEFAULT <<
                    RXQ_CFG_816X_IDT_TBL_SIZE_SHIFT) &
                    RXQ_CFG_816X_IDT_TBL_SIZE_MASK;
                if ((sc->alc_flags & ALC_FLAG_FASTETHER) == 0)
                        reg |= RXQ_CFG_ASPM_THROUGHPUT_LIMIT_100M;
        } else {
                if ((sc->alc_flags & ALC_FLAG_FASTETHER) == 0 &&
                    sc->alc_ident->deviceid != DEVICEID_ATHEROS_AR8151_V2)
                        reg |= RXQ_CFG_ASPM_THROUGHPUT_LIMIT_100M;
        }
        CSR_WRITE_4(sc, ALC_RXQ_CFG, reg);

        /* Configure DMA parameters. */
        reg = DMA_CFG_OUT_ORDER | DMA_CFG_RD_REQ_PRI;
        reg |= sc->alc_rcb;
        if ((sc->alc_flags & ALC_FLAG_CMB_BUG) == 0)
                reg |= DMA_CFG_CMB_ENB;
        if ((sc->alc_flags & ALC_FLAG_SMB_BUG) == 0)
                reg |= DMA_CFG_SMB_ENB;
        else
                reg |= DMA_CFG_SMB_DIS;
        reg |= (sc->alc_dma_rd_burst & DMA_CFG_RD_BURST_MASK) <<
            DMA_CFG_RD_BURST_SHIFT;
        reg |= (sc->alc_dma_wr_burst & DMA_CFG_WR_BURST_MASK) <<
            DMA_CFG_WR_BURST_SHIFT;
        reg |= (DMA_CFG_RD_DELAY_CNT_DEFAULT << DMA_CFG_RD_DELAY_CNT_SHIFT) &
            DMA_CFG_RD_DELAY_CNT_MASK;
        reg |= (DMA_CFG_WR_DELAY_CNT_DEFAULT << DMA_CFG_WR_DELAY_CNT_SHIFT) &
            DMA_CFG_WR_DELAY_CNT_MASK;
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0) {
                switch (AR816X_REV(sc->alc_rev)) {
                case AR816X_REV_A0:
                case AR816X_REV_A1:
                        reg |= DMA_CFG_RD_CHNL_SEL_2;
                        break;
                case AR816X_REV_B0:
                        /* FALLTHROUGH */
                default:
                        reg |= DMA_CFG_RD_CHNL_SEL_4;
                        break;
                }
        }
        CSR_WRITE_4(sc, ALC_DMA_CFG, reg);

        /*
         * Configure Tx/Rx MACs.
         *  - Auto-padding for short frames.
         *  - Enable CRC generation.
         *  Actual reconfiguration of MAC for resolved speed/duplex
         *  is followed after detection of link establishment.
         *  AR813x/AR815x always does checksum computation regardless
         *  of MAC_CFG_RXCSUM_ENB bit. Also the controller is known to
         *  have bug in protocol field in Rx return structure so
         *  these controllers can't handle fragmented frames. Disable
         *  Rx checksum offloading until there is a newer controller
         *  that has sane implementation.
         */
        reg = MAC_CFG_TX_CRC_ENB | MAC_CFG_TX_AUTO_PAD | MAC_CFG_FULL_DUPLEX |
            ((MAC_CFG_PREAMBLE_DEFAULT << MAC_CFG_PREAMBLE_SHIFT) &
            MAC_CFG_PREAMBLE_MASK);
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) != 0 ||
            sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8151 ||
            sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8151_V2 ||
            sc->alc_ident->deviceid == DEVICEID_ATHEROS_AR8152_B2)
                reg |= MAC_CFG_HASH_ALG_CRC32 | MAC_CFG_SPEED_MODE_SW;
        if ((sc->alc_flags & ALC_FLAG_FASTETHER) != 0)
                reg |= MAC_CFG_SPEED_10_100;
        else
                reg |= MAC_CFG_SPEED_1000;
        CSR_WRITE_4(sc, ALC_MAC_CFG, reg);

        /* Set up the receive filter. */
        alc_rxfilter(sc);
        alc_rxvlan(sc);

        /* Acknowledge all pending interrupts and clear it. */
        CSR_WRITE_4(sc, ALC_INTR_MASK, ALC_INTRS);
        CSR_WRITE_4(sc, ALC_INTR_STATUS, 0xFFFFFFFF);
        CSR_WRITE_4(sc, ALC_INTR_STATUS, 0);

        if_setdrvflagbits(ifp, IFF_DRV_RUNNING, 0);
        if_setdrvflagbits(ifp, 0, IFF_DRV_OACTIVE);

        sc->alc_flags &= ~ALC_FLAG_LINK;
        /* Switch to the current media. */
        alc_mediachange_locked(sc);

        callout_reset(&sc->alc_tick_ch, hz, alc_tick, sc);
}

static void
alc_stop(struct alc_softc *sc)
{
        if_t ifp;
        struct alc_txdesc *txd;
        struct alc_rxdesc *rxd;
        uint32_t reg;
        int i;

        ALC_LOCK_ASSERT(sc);
        /*
         * Mark the interface down and cancel the watchdog timer.
         */
        ifp = sc->alc_ifp;
        if_setdrvflagbits(ifp, 0, (IFF_DRV_RUNNING | IFF_DRV_OACTIVE));
        sc->alc_flags &= ~ALC_FLAG_LINK;
        callout_stop(&sc->alc_tick_ch);
        sc->alc_watchdog_timer = 0;
        alc_stats_update(sc);
        /* Disable interrupts. */
        CSR_WRITE_4(sc, ALC_INTR_MASK, 0);
        CSR_WRITE_4(sc, ALC_INTR_STATUS, 0xFFFFFFFF);
        /* Disable DMA. */
        reg = CSR_READ_4(sc, ALC_DMA_CFG);
        reg &= ~(DMA_CFG_CMB_ENB | DMA_CFG_SMB_ENB);
        reg |= DMA_CFG_SMB_DIS;
        CSR_WRITE_4(sc, ALC_DMA_CFG, reg);
        DELAY(1000);
        /* Stop Rx/Tx MACs. */
        alc_stop_mac(sc);
        /* Disable interrupts which might be touched in taskq handler. */
        CSR_WRITE_4(sc, ALC_INTR_STATUS, 0xFFFFFFFF);
        /* Disable L0s/L1s */
        alc_aspm(sc, 0, IFM_UNKNOWN);
        /* Reclaim Rx buffers that have been processed. */
        if (sc->alc_cdata.alc_rxhead != NULL)
                m_freem(sc->alc_cdata.alc_rxhead);
        ALC_RXCHAIN_RESET(sc);
        /*
         * Free Tx/Rx mbufs still in the queues.
         */
        for (i = 0; i < ALC_RX_RING_CNT; i++) {
                rxd = &sc->alc_cdata.alc_rxdesc[i];
                if (rxd->rx_m != NULL) {
                        bus_dmamap_sync(sc->alc_cdata.alc_rx_tag,
                            rxd->rx_dmamap, BUS_DMASYNC_POSTREAD);
                        bus_dmamap_unload(sc->alc_cdata.alc_rx_tag,
                            rxd->rx_dmamap);
                        m_freem(rxd->rx_m);
                        rxd->rx_m = NULL;
                }
        }
        for (i = 0; i < ALC_TX_RING_CNT; i++) {
                txd = &sc->alc_cdata.alc_txdesc[i];
                if (txd->tx_m != NULL) {
                        bus_dmamap_sync(sc->alc_cdata.alc_tx_tag,
                            txd->tx_dmamap, BUS_DMASYNC_POSTWRITE);
                        bus_dmamap_unload(sc->alc_cdata.alc_tx_tag,
                            txd->tx_dmamap);
                        m_freem(txd->tx_m);
                        txd->tx_m = NULL;
                }
        }
}

static void
alc_stop_mac(struct alc_softc *sc)
{
        uint32_t reg;
        int i;

        alc_stop_queue(sc);
        /* Disable Rx/Tx MAC. */
        reg = CSR_READ_4(sc, ALC_MAC_CFG);
        if ((reg & (MAC_CFG_TX_ENB | MAC_CFG_RX_ENB)) != 0) {
                reg &= ~(MAC_CFG_TX_ENB | MAC_CFG_RX_ENB);
                CSR_WRITE_4(sc, ALC_MAC_CFG, reg);
        }
        for (i = ALC_TIMEOUT; i > 0; i--) {
                reg = CSR_READ_4(sc, ALC_IDLE_STATUS);
                if ((reg & (IDLE_STATUS_RXMAC | IDLE_STATUS_TXMAC)) == 0)
                        break;
                DELAY(10);
        }
        if (i == 0)
                device_printf(sc->alc_dev,
                    "could not disable Rx/Tx MAC(0x%08x)!\n", reg);
}

static void
alc_start_queue(struct alc_softc *sc)
{
        uint32_t qcfg[] = {
                0,
                RXQ_CFG_QUEUE0_ENB,
                RXQ_CFG_QUEUE0_ENB | RXQ_CFG_QUEUE1_ENB,
                RXQ_CFG_QUEUE0_ENB | RXQ_CFG_QUEUE1_ENB | RXQ_CFG_QUEUE2_ENB,
                RXQ_CFG_ENB
        };
        uint32_t cfg;

        ALC_LOCK_ASSERT(sc);

        /* Enable RxQ. */
        cfg = CSR_READ_4(sc, ALC_RXQ_CFG);
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) == 0) {
                cfg &= ~RXQ_CFG_ENB;
                cfg |= qcfg[1];
        } else
                cfg |= RXQ_CFG_QUEUE0_ENB;
        CSR_WRITE_4(sc, ALC_RXQ_CFG, cfg);
        /* Enable TxQ. */
        cfg = CSR_READ_4(sc, ALC_TXQ_CFG);
        cfg |= TXQ_CFG_ENB;
        CSR_WRITE_4(sc, ALC_TXQ_CFG, cfg);
}

static void
alc_stop_queue(struct alc_softc *sc)
{
        uint32_t reg;
        int i;

        /* Disable RxQ. */
        reg = CSR_READ_4(sc, ALC_RXQ_CFG);
        if ((sc->alc_flags & ALC_FLAG_AR816X_FAMILY) == 0) {
                if ((reg & RXQ_CFG_ENB) != 0) {
                        reg &= ~RXQ_CFG_ENB;
                        CSR_WRITE_4(sc, ALC_RXQ_CFG, reg);
                }
        } else {
                if ((reg & RXQ_CFG_QUEUE0_ENB) != 0) {
                        reg &= ~RXQ_CFG_QUEUE0_ENB;
                        CSR_WRITE_4(sc, ALC_RXQ_CFG, reg);
                }
        }
        /* Disable TxQ. */
        reg = CSR_READ_4(sc, ALC_TXQ_CFG);
        if ((reg & TXQ_CFG_ENB) != 0) {
                reg &= ~TXQ_CFG_ENB;
                CSR_WRITE_4(sc, ALC_TXQ_CFG, reg);
        }
        DELAY(40);
        for (i = ALC_TIMEOUT; i > 0; i--) {
                reg = CSR_READ_4(sc, ALC_IDLE_STATUS);
                if ((reg & (IDLE_STATUS_RXQ | IDLE_STATUS_TXQ)) == 0)
                        break;
                DELAY(10);
        }
        if (i == 0)
                device_printf(sc->alc_dev,
                    "could not disable RxQ/TxQ (0x%08x)!\n", reg);
}

static void
alc_init_tx_ring(struct alc_softc *sc)
{
        struct alc_ring_data *rd;
        struct alc_txdesc *txd;
        int i;

        ALC_LOCK_ASSERT(sc);

        sc->alc_cdata.alc_tx_prod = 0;
        sc->alc_cdata.alc_tx_cons = 0;
        sc->alc_cdata.alc_tx_cnt = 0;

        rd = &sc->alc_rdata;
        bzero(rd->alc_tx_ring, ALC_TX_RING_SZ);
        for (i = 0; i < ALC_TX_RING_CNT; i++) {
                txd = &sc->alc_cdata.alc_txdesc[i];
                txd->tx_m = NULL;
        }

        bus_dmamap_sync(sc->alc_cdata.alc_tx_ring_tag,
            sc->alc_cdata.alc_tx_ring_map, BUS_DMASYNC_PREWRITE);
}

static int
alc_init_rx_ring(struct alc_softc *sc)
{
        struct alc_ring_data *rd;
        struct alc_rxdesc *rxd;
        int i;

        ALC_LOCK_ASSERT(sc);

        sc->alc_cdata.alc_rx_cons = ALC_RX_RING_CNT - 1;
        sc->alc_morework = 0;
        rd = &sc->alc_rdata;
        bzero(rd->alc_rx_ring, ALC_RX_RING_SZ);
        for (i = 0; i < ALC_RX_RING_CNT; i++) {
                rxd = &sc->alc_cdata.alc_rxdesc[i];
                rxd->rx_m = NULL;
                rxd->rx_desc = &rd->alc_rx_ring[i];
                if (alc_newbuf(sc, rxd) != 0)
                        return (ENOBUFS);
        }

        /*
         * Since controller does not update Rx descriptors, driver
         * does have to read Rx descriptors back so BUS_DMASYNC_PREWRITE
         * is enough to ensure coherence.
         */
        bus_dmamap_sync(sc->alc_cdata.alc_rx_ring_tag,
            sc->alc_cdata.alc_rx_ring_map, BUS_DMASYNC_PREWRITE);
        /* Let controller know availability of new Rx buffers. */
        CSR_WRITE_4(sc, ALC_MBOX_RD0_PROD_IDX, sc->alc_cdata.alc_rx_cons);

        return (0);
}

static void
alc_init_rr_ring(struct alc_softc *sc)
{
        struct alc_ring_data *rd;

        ALC_LOCK_ASSERT(sc);

        sc->alc_cdata.alc_rr_cons = 0;
        ALC_RXCHAIN_RESET(sc);

        rd = &sc->alc_rdata;
        bzero(rd->alc_rr_ring, ALC_RR_RING_SZ);
        bus_dmamap_sync(sc->alc_cdata.alc_rr_ring_tag,
            sc->alc_cdata.alc_rr_ring_map,
            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
}

static void
alc_init_cmb(struct alc_softc *sc)
{
        struct alc_ring_data *rd;

        ALC_LOCK_ASSERT(sc);

        rd = &sc->alc_rdata;
        bzero(rd->alc_cmb, ALC_CMB_SZ);
        bus_dmamap_sync(sc->alc_cdata.alc_cmb_tag, sc->alc_cdata.alc_cmb_map,
            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
}

static void
alc_init_smb(struct alc_softc *sc)
{
        struct alc_ring_data *rd;

        ALC_LOCK_ASSERT(sc);

        rd = &sc->alc_rdata;
        bzero(rd->alc_smb, ALC_SMB_SZ);
        bus_dmamap_sync(sc->alc_cdata.alc_smb_tag, sc->alc_cdata.alc_smb_map,
            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
}

static void
alc_rxvlan(struct alc_softc *sc)
{
        if_t ifp;
        uint32_t reg;

        ALC_LOCK_ASSERT(sc);

        ifp = sc->alc_ifp;
        reg = CSR_READ_4(sc, ALC_MAC_CFG);
        if ((if_getcapenable(ifp) & IFCAP_VLAN_HWTAGGING) != 0)
                reg |= MAC_CFG_VLAN_TAG_STRIP;
        else
                reg &= ~MAC_CFG_VLAN_TAG_STRIP;
        CSR_WRITE_4(sc, ALC_MAC_CFG, reg);
}

static u_int
alc_hash_maddr(void *arg, struct sockaddr_dl *sdl, u_int cnt)
{
        uint32_t *mchash = arg;
        uint32_t crc;

        crc = ether_crc32_be(LLADDR(sdl), ETHER_ADDR_LEN);
        mchash[crc >> 31] |= 1 << ((crc >> 26) & 0x1f);

        return (1);
}

static void
alc_rxfilter(struct alc_softc *sc)
{
        if_t ifp;
        uint32_t mchash[2];
        uint32_t rxcfg;

        ALC_LOCK_ASSERT(sc);

        ifp = sc->alc_ifp;

        bzero(mchash, sizeof(mchash));
        rxcfg = CSR_READ_4(sc, ALC_MAC_CFG);
        rxcfg &= ~(MAC_CFG_ALLMULTI | MAC_CFG_BCAST | MAC_CFG_PROMISC);
        if ((if_getflags(ifp) & IFF_BROADCAST) != 0)
                rxcfg |= MAC_CFG_BCAST;
        if ((if_getflags(ifp) & (IFF_PROMISC | IFF_ALLMULTI)) != 0) {
                if ((if_getflags(ifp) & IFF_PROMISC) != 0)
                        rxcfg |= MAC_CFG_PROMISC;
                if ((if_getflags(ifp) & IFF_ALLMULTI) != 0)
                        rxcfg |= MAC_CFG_ALLMULTI;
                mchash[0] = 0xFFFFFFFF;
                mchash[1] = 0xFFFFFFFF;
                goto chipit;
        }

        if_foreach_llmaddr(ifp, alc_hash_maddr, mchash);

chipit:
        CSR_WRITE_4(sc, ALC_MAR0, mchash[0]);
        CSR_WRITE_4(sc, ALC_MAR1, mchash[1]);
        CSR_WRITE_4(sc, ALC_MAC_CFG, rxcfg);
}

static int
sysctl_int_range(SYSCTL_HANDLER_ARGS, int low, int high)
{
        int error, value;

        if (arg1 == NULL)
                return (EINVAL);
        value = *(int *)arg1;
        error = sysctl_handle_int(oidp, &value, 0, req);
        if (error || req->newptr == NULL)
                return (error);
        if (value < low || value > high)
                return (EINVAL);
        *(int *)arg1 = value;

        return (0);
}

static int
sysctl_hw_alc_proc_limit(SYSCTL_HANDLER_ARGS)
{
        return (sysctl_int_range(oidp, arg1, arg2, req,
            ALC_PROC_MIN, ALC_PROC_MAX));
}

static int
sysctl_hw_alc_int_mod(SYSCTL_HANDLER_ARGS)
{

        return (sysctl_int_range(oidp, arg1, arg2, req,
            ALC_IM_TIMER_MIN, ALC_IM_TIMER_MAX));
}

#ifdef DEBUGNET
static void
alc_debugnet_init(if_t ifp, int *nrxr, int *ncl, int *clsize)
{
        struct alc_softc *sc __diagused;

        sc = if_getsoftc(ifp);
        KASSERT(sc->alc_buf_size <= MCLBYTES, ("incorrect cluster size"));

        *nrxr = ALC_RX_RING_CNT;
        *ncl = DEBUGNET_MAX_IN_FLIGHT;
        *clsize = MCLBYTES;
}

static void
alc_debugnet_event(if_t ifp __unused, enum debugnet_ev event __unused)
{
}

static int
alc_debugnet_transmit(if_t ifp, struct mbuf *m)
{
        struct alc_softc *sc;
        int error;

        sc = if_getsoftc(ifp);
        if ((if_getdrvflags(ifp) & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
            IFF_DRV_RUNNING)
                return (EBUSY);

        error = alc_encap(sc, &m);
        if (error == 0)
                alc_start_tx(sc);
        return (error);
}

static int
alc_debugnet_poll(if_t ifp, int count)
{
        struct alc_softc *sc;

        sc = if_getsoftc(ifp);
        if ((if_getdrvflags(ifp) & (IFF_DRV_RUNNING | IFF_DRV_OACTIVE)) !=
            IFF_DRV_RUNNING)
                return (EBUSY);

        alc_txeof(sc);
        return (alc_rxintr(sc, count));
}
#endif /* DEBUGNET */