root/sys/dev/ieee1394/fwohci.c
/*      $NetBSD: fwohci.c,v 1.152 2023/08/10 20:49:20 mrg Exp $ */

/*-
 * Copyright (c) 2003 Hidetoshi Shimokawa
 * Copyright (c) 1998-2002 Katsushi Kobayashi and Hidetoshi Shimokawa
 * 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, 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the acknowledgement as bellow:
 *
 *    This product includes software developed by K. Kobayashi and H. Shimokawa
 *
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 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.
 *
 * $FreeBSD: src/sys/dev/firewire/fwohci.c,v 1.98 2009/02/13 17:44:07 sbruno Exp $
 *
 */
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: fwohci.c,v 1.152 2023/08/10 20:49:20 mrg Exp $");

#include <sys/param.h>
#include <sys/atomic.h>
#include <sys/bus.h>
#include <sys/device.h>
#include <sys/errno.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/malloc.h>
#include <sys/mbuf.h>
#include <sys/proc.h>
#include <sys/reboot.h>
#include <sys/select.h>
#include <sys/sysctl.h>
#include <sys/systm.h>

#include <dev/ieee1394/firewire.h>
#include <dev/ieee1394/firewirereg.h>
#include <dev/ieee1394/fwdma.h>
#include <dev/ieee1394/fwohcireg.h>
#include <dev/ieee1394/fwohcivar.h>
#include <dev/ieee1394/firewire_phy.h>

#include "ioconf.h"

#undef OHCI_DEBUG

static int nocyclemaster = 0;
int firewire_phydma_enable = 1;
/*
 * Setup sysctl(3) MIB, hw.fwohci.*
 *
 * TBD condition CTLFLAG_PERMANENT on being a module or not
 */
SYSCTL_SETUP(sysctl_fwohci, "sysctl fwohci(4) subtree setup")
{
        int rc, fwohci_node_num;
        const struct sysctlnode *node;

        if ((rc = sysctl_createv(clog, 0, NULL, &node,
            CTLFLAG_PERMANENT, CTLTYPE_NODE, "fwohci",
            SYSCTL_DESCR("fwohci controls"),
            NULL, 0, NULL, 0, CTL_HW, CTL_CREATE, CTL_EOL)) != 0) {
                goto err;
        }
        fwohci_node_num = node->sysctl_num;

        /* fwohci no cyclemaster flag */
        if ((rc = sysctl_createv(clog, 0, NULL, &node,
            CTLFLAG_PERMANENT | CTLFLAG_READWRITE, CTLTYPE_INT,
            "nocyclemaster", SYSCTL_DESCR("Do not send cycle start packets"),
            NULL, 0, &nocyclemaster,
            0, CTL_HW, fwohci_node_num, CTL_CREATE, CTL_EOL)) != 0) {
                goto err;
        }

        /* fwohci physical request DMA enable */
        if ((rc = sysctl_createv(clog, 0, NULL, &node,
            CTLFLAG_PERMANENT | CTLFLAG_READWRITE, CTLTYPE_INT, "phydma_enable",
            SYSCTL_DESCR("Allow physical request DMA from firewire"),
            NULL, 0, &firewire_phydma_enable,
            0, CTL_HW, fwohci_node_num, CTL_CREATE, CTL_EOL)) != 0) {
                goto err;
        }
        return;

err:
        aprint_error("%s: sysctl_createv failed (rc = %d)\n", __func__, rc);
}

static const char * const dbcode[16] = {
    "OUTM", "OUTL", "INPM", "INPL", "STOR", "LOAD", "NOP ", "STOP",
    "", "", "", "", "", "", "", ""
};

static const char * const dbkey[8] = {
    "ST0", "ST1", "ST2", "ST3", "UNDEF", "REG", "SYS", "DEV"
};

static const char * const dbcond[4] = { "NEV", "C=1", "C=0", "ALL" };
static const char * const fwohcicode[32] = {
        "No stat",      "Undef",        "long",         "miss Ack err",
        "FIFO underrun","FIFO overrun", "desc err",     "data read err",
        "data write err","bus reset",   "timeout",      "tcode err",
        "Undef",        "Undef",        "unknown event","flushed",
        "Undef",        "ack complete", "ack pend",     "Undef",
        "ack busy_X",   "ack busy_A",   "ack busy_B",   "Undef",
        "Undef",        "Undef",        "Undef",        "ack tardy",
        "Undef",        "ack data_err", "ack type_err", ""
};

#define MAX_SPEED 3
extern const char *fw_linkspeed[];
static uint32_t const tagbit[4] = { 1 << 28, 1 << 29, 1 << 30, 1 << 31 };

static const struct tcode_info tinfo[] = {
/*              hdr_len block   flag    valid_response */
/* 0 WREQQ  */ { 16,    FWTI_REQ | FWTI_TLABEL, FWTCODE_WRES },
/* 1 WREQB  */ { 16,    FWTI_REQ | FWTI_TLABEL | FWTI_BLOCK_ASY, FWTCODE_WRES },
/* 2 WRES   */ { 12,    FWTI_RES, 0xff },
/* 3 XXX    */ {  0,    0, 0xff },
/* 4 RREQQ  */ { 12,    FWTI_REQ | FWTI_TLABEL, FWTCODE_RRESQ },
/* 5 RREQB  */ { 16,    FWTI_REQ | FWTI_TLABEL, FWTCODE_RRESB },
/* 6 RRESQ  */ { 16,    FWTI_RES, 0xff },
/* 7 RRESB  */ { 16,    FWTI_RES | FWTI_BLOCK_ASY, 0xff },
/* 8 CYCS   */ {  0,    0, 0xff },
/* 9 LREQ   */ { 16,    FWTI_REQ | FWTI_TLABEL | FWTI_BLOCK_ASY, FWTCODE_LRES },
/* a STREAM */ {  4,    FWTI_REQ | FWTI_BLOCK_STR, 0xff },
/* b LRES   */ { 16,    FWTI_RES | FWTI_BLOCK_ASY, 0xff },
/* c XXX    */ {  0,    0, 0xff },
/* d XXX    */ {  0,    0, 0xff },
/* e PHY    */ { 12,    FWTI_REQ, 0xff },
/* f XXX    */ {  0,    0, 0xff }
};

#define OHCI_WRITE_SIGMASK 0xffff0000
#define OHCI_READ_SIGMASK 0xffff0000


int fwohci_print(void *, const char *);

static int fwohci_ioctl(dev_t, u_long, void *, int, struct lwp *);

static uint32_t fwohci_cyctimer(struct firewire_comm *);
static uint32_t fwohci_set_bus_manager(struct firewire_comm *, u_int);
static void fwohci_ibr(struct firewire_comm *);
static int fwohci_irx_enable(struct firewire_comm *, int);
static int fwohci_irx_disable(struct firewire_comm *, int);
static int fwohci_itxbuf_enable(struct firewire_comm *, int);
static int fwohci_itx_disable(struct firewire_comm *, int);
static void fwohci_timeout(struct firewire_comm *fc);
#if BYTE_ORDER == BIG_ENDIAN
static void fwohci_irx_post(struct firewire_comm *, uint32_t *);
#endif
static void fwohci_set_intr(struct firewire_comm *, int);

static uint32_t fwphy_rddata(struct fwohci_softc *, uint32_t);
static uint32_t fwphy_wrdata(struct fwohci_softc *, uint32_t, uint32_t);
static int fwohci_probe_phy(struct fwohci_softc *);
static void fwohci_reset(struct fwohci_softc *);
static void fwohci_execute_db(struct fwohcidb_tr *, bus_dmamap_t);
static void fwohci_start(struct fwohci_softc *, struct fwohci_dbch *);
static void fwohci_start_atq(struct firewire_comm *);
static void fwohci_start_ats(struct firewire_comm *);
static void fwohci_txd(struct fwohci_softc *, struct fwohci_dbch *);
static void fwohci_db_free(struct fwohci_softc *, struct fwohci_dbch *);
static void fwohci_db_init(struct fwohci_softc *, struct fwohci_dbch *);
static int fwohci_rx_enable(struct fwohci_softc *, struct fwohci_dbch *);
static int fwohci_tx_enable(struct fwohci_softc *, struct fwohci_dbch *);
static int fwohci_next_cycle(struct fwohci_softc *, int);
#ifdef OHCI_DEBUG
static void fwohci_dump_intr(struct fwohci_softc *, uint32_t);
#endif
static void fwohci_intr_core(struct fwohci_softc *, uint32_t);
static void fwohci_intr_dma(struct fwohci_softc *, uint32_t);
static void fwohci_task_sid(struct fwohci_softc *);
static void fwohci_task_dma(struct fwohci_softc *);
static void fwohci_tbuf_update(struct fwohci_softc *, int);
static void fwohci_rbuf_update(struct fwohci_softc *, int);
static void dump_dma(struct fwohci_softc *, uint32_t);
static void dump_db(struct fwohci_softc *, uint32_t);
static void print_db(struct fwohcidb_tr *, struct fwohcidb *, uint32_t,
                     uint32_t);
static void fwohci_txbufdb(struct fwohci_softc *, int, struct fw_bulkxfer *);
static int fwohci_add_tx_buf(struct fwohci_dbch *, struct fwohcidb_tr *, int);
static int fwohci_add_rx_buf(struct fwohci_dbch *, struct fwohcidb_tr *, int,
                             struct fwdma_alloc *);
static int fwohci_arcv_swap(struct fw_pkt *, int);
static int fwohci_get_plen(struct fwohci_softc *, struct fwohci_dbch *,
                           struct fw_pkt *);
static void fwohci_arcv_free_buf(struct fwohci_softc *, struct fwohci_dbch *,
                                 struct fwohcidb_tr *, int);
static void fwohci_arcv(struct fwohci_softc *, struct fwohci_dbch *);


/*
 * memory allocated for DMA programs
 */
#define DMA_PROG_ALLOC          (8 * PAGE_SIZE)

#define NDB FWMAXQUEUE

#define OHCI_VERSION            0x000
#define OHCI_ATRETRY            0x008
#define OHCI_CROMHDR            0x018
#define OHCI_BUS_OPT            0x020
#define OHCI_BUSIRMC            (1U << 31)
#define OHCI_BUSCMC             (1 << 30)
#define OHCI_BUSISC             (1 << 29)
#define OHCI_BUSBMC             (1 << 28)
#define OHCI_BUSPMC             (1 << 27)
#define OHCI_BUSFNC \
        (OHCI_BUSIRMC | OHCI_BUSCMC | OHCI_BUSISC | OHCI_BUSBMC | OHCI_BUSPMC)

#define OHCI_EUID_HI            0x024
#define OHCI_EUID_LO            0x028

#define OHCI_CROMPTR            0x034
#define OHCI_HCCCTL             0x050
#define OHCI_HCCCTLCLR          0x054
#define OHCI_AREQHI             0x100
#define OHCI_AREQHICLR          0x104
#define OHCI_AREQLO             0x108
#define OHCI_AREQLOCLR          0x10c
#define OHCI_PREQHI             0x110
#define OHCI_PREQHICLR          0x114
#define OHCI_PREQLO             0x118
#define OHCI_PREQLOCLR          0x11c
#define OHCI_PREQUPPER          0x120

#define OHCI_SID_BUF            0x064
#define OHCI_SID_CNT            0x068
#define OHCI_SID_ERR            (1U << 31)
#define OHCI_SID_CNT_MASK       0xffc

#define OHCI_IT_STAT            0x090
#define OHCI_IT_STATCLR         0x094
#define OHCI_IT_MASK            0x098
#define OHCI_IT_MASKCLR         0x09c

#define OHCI_IR_STAT            0x0a0
#define OHCI_IR_STATCLR         0x0a4
#define OHCI_IR_MASK            0x0a8
#define OHCI_IR_MASKCLR         0x0ac

#define OHCI_LNKCTL             0x0e0
#define OHCI_LNKCTLCLR          0x0e4

#define OHCI_PHYACCESS          0x0ec
#define OHCI_CYCLETIMER         0x0f0

#define OHCI_DMACTL(off)        (off)
#define OHCI_DMACTLCLR(off)     (off + 0x04)
#define OHCI_DMACMD(off)        (off + 0x0c)
#define OHCI_DMAMATCH(off)      (off + 0x10)

#define OHCI_ATQOFF             0x180
#define OHCI_ATQCTL             OHCI_ATQOFF
#define OHCI_ATQCTLCLR          (OHCI_ATQOFF + 0x04)
#define OHCI_ATQCMD             (OHCI_ATQOFF + 0x0c)
#define OHCI_ATQMATCH           (OHCI_ATQOFF + 0x10)

#define OHCI_ATSOFF             0x1a0
#define OHCI_ATSCTL             OHCI_ATSOFF
#define OHCI_ATSCTLCLR          (OHCI_ATSOFF + 0x04)
#define OHCI_ATSCMD             (OHCI_ATSOFF + 0x0c)
#define OHCI_ATSMATCH           (OHCI_ATSOFF + 0x10)

#define OHCI_ARQOFF             0x1c0
#define OHCI_ARQCTL             OHCI_ARQOFF
#define OHCI_ARQCTLCLR          (OHCI_ARQOFF + 0x04)
#define OHCI_ARQCMD             (OHCI_ARQOFF + 0x0c)
#define OHCI_ARQMATCH           (OHCI_ARQOFF + 0x10)

#define OHCI_ARSOFF             0x1e0
#define OHCI_ARSCTL             OHCI_ARSOFF
#define OHCI_ARSCTLCLR          (OHCI_ARSOFF + 0x04)
#define OHCI_ARSCMD             (OHCI_ARSOFF + 0x0c)
#define OHCI_ARSMATCH           (OHCI_ARSOFF + 0x10)

#define OHCI_ITOFF(CH)          (0x200 + 0x10 * (CH))
#define OHCI_ITCTL(CH)          (OHCI_ITOFF(CH))
#define OHCI_ITCTLCLR(CH)       (OHCI_ITOFF(CH) + 0x04)
#define OHCI_ITCMD(CH)          (OHCI_ITOFF(CH) + 0x0c)

#define OHCI_IROFF(CH)          (0x400 + 0x20 * (CH))
#define OHCI_IRCTL(CH)          (OHCI_IROFF(CH))
#define OHCI_IRCTLCLR(CH)       (OHCI_IROFF(CH) + 0x04)
#define OHCI_IRCMD(CH)          (OHCI_IROFF(CH) + 0x0c)
#define OHCI_IRMATCH(CH)        (OHCI_IROFF(CH) + 0x10)

#define ATRQ_CH  0
#define ATRS_CH  1
#define ARRQ_CH  2
#define ARRS_CH  3
#define ITX_CH   4
#define IRX_CH  36


/*
 * Call fwohci_init before fwohci_attach to initialize the kernel's
 * data structures well enough that fwohci_detach won't crash, even if
 * fwohci_attach fails.
 */

void
fwohci_init(struct fwohci_softc *sc)
{
        sc->fc.arq = &sc->arrq.xferq;
        sc->fc.ars = &sc->arrs.xferq;
        sc->fc.atq = &sc->atrq.xferq;
        sc->fc.ats = &sc->atrs.xferq;

        sc->arrq.xferq.psize = roundup2(FWPMAX_S400, PAGE_SIZE);
        sc->arrs.xferq.psize = roundup2(FWPMAX_S400, PAGE_SIZE);
        sc->atrq.xferq.psize = roundup2(FWPMAX_S400, PAGE_SIZE);
        sc->atrs.xferq.psize = roundup2(FWPMAX_S400, PAGE_SIZE);

        sc->arrq.xferq.start = NULL;
        sc->arrs.xferq.start = NULL;
        sc->atrq.xferq.start = fwohci_start_atq;
        sc->atrs.xferq.start = fwohci_start_ats;

        sc->arrq.xferq.buf = NULL;
        sc->arrs.xferq.buf = NULL;
        sc->atrq.xferq.buf = NULL;
        sc->atrs.xferq.buf = NULL;

        sc->arrq.xferq.dmach = -1;
        sc->arrs.xferq.dmach = -1;
        sc->atrq.xferq.dmach = -1;
        sc->atrs.xferq.dmach = -1;

        sc->arrq.ndesc = 1;
        sc->arrs.ndesc = 1;
        sc->atrq.ndesc = 8;     /* equal to maximum of mbuf chains */
        sc->atrs.ndesc = 2;

        sc->arrq.ndb = NDB;
        sc->arrs.ndb = NDB / 2;
        sc->atrq.ndb = NDB;
        sc->atrs.ndb = NDB / 2;

        sc->arrq.off = OHCI_ARQOFF;
        sc->arrs.off = OHCI_ARSOFF;
        sc->atrq.off = OHCI_ATQOFF;
        sc->atrs.off = OHCI_ATSOFF;

        sc->fc.tcode = tinfo;

        sc->fc.cyctimer = fwohci_cyctimer;
        sc->fc.ibr = fwohci_ibr;
        sc->fc.set_bmr = fwohci_set_bus_manager;
        sc->fc.ioctl = fwohci_ioctl;
        sc->fc.irx_enable = fwohci_irx_enable;
        sc->fc.irx_disable = fwohci_irx_disable;

        sc->fc.itx_enable = fwohci_itxbuf_enable;
        sc->fc.itx_disable = fwohci_itx_disable;
        sc->fc.timeout = fwohci_timeout;
        sc->fc.set_intr = fwohci_set_intr;
#if BYTE_ORDER == BIG_ENDIAN
        sc->fc.irx_post = fwohci_irx_post;
#else
        sc->fc.irx_post = NULL;
#endif
        sc->fc.itx_post = NULL;

        sc->intmask = sc->irstat = sc->itstat = 0;

        fw_init(&sc->fc);
}

/*
 * Call fwohci_attach after fwohci_init to initialize the hardware and
 * attach children.
 */

int
fwohci_attach(struct fwohci_softc *sc)
{
        uint32_t reg;
        uint8_t ui[8];
        int i, mver;

/* OHCI version */
        reg = OREAD(sc, OHCI_VERSION);
        mver = (reg >> 16) & 0xff;
        aprint_normal_dev(sc->fc.dev, "OHCI version %x.%x (ROM=%d)\n",
            mver, reg & 0xff, (reg >> 24) & 1);
        if (mver < 1 || mver > 9) {
                aprint_error_dev(sc->fc.dev, "invalid OHCI version\n");
                return ENXIO;
        }

/* Available Isochronous DMA channel probe */
        OWRITE(sc, OHCI_IT_MASK, 0xffffffff);
        OWRITE(sc, OHCI_IR_MASK, 0xffffffff);
        reg = OREAD(sc, OHCI_IT_MASK) & OREAD(sc, OHCI_IR_MASK);
        OWRITE(sc, OHCI_IT_MASKCLR, 0xffffffff);
        OWRITE(sc, OHCI_IR_MASKCLR, 0xffffffff);
        for (i = 0; i < 0x20; i++)
                if ((reg & (1 << i)) == 0)
                        break;
        sc->fc.nisodma = i;
        aprint_normal_dev(sc->fc.dev, "No. of Isochronous channels is %d.\n",
            i);
        if (i == 0)
                return ENXIO;

        for (i = 0; i < sc->fc.nisodma; i++) {
                sc->fc.it[i] = &sc->it[i].xferq;
                sc->fc.ir[i] = &sc->ir[i].xferq;
                sc->it[i].xferq.dmach = i;
                sc->ir[i].xferq.dmach = i;
                sc->it[i].ndb = 0;
                sc->ir[i].ndb = 0;
                sc->it[i].off = OHCI_ITOFF(i);
                sc->ir[i].off = OHCI_IROFF(i);
        }

        fw_init_isodma(&sc->fc);

        sc->fc.config_rom = fwdma_alloc_setup(sc->fc.dev, sc->fc.dmat,
            CROMSIZE, &sc->crom_dma, CROMSIZE, BUS_DMA_NOWAIT);
        if (sc->fc.config_rom == NULL) {
                aprint_error_dev(sc->fc.dev, "config_rom alloc failed.\n");
                return ENOMEM;
        }

#if 0
        memset(sc->fc.config_rom, 0, CROMSIZE);
        sc->fc.config_rom[1] = 0x31333934;
        sc->fc.config_rom[2] = 0xf000a002;
        sc->fc.config_rom[3] = OREAD(sc, OHCI_EUID_HI);
        sc->fc.config_rom[4] = OREAD(sc, OHCI_EUID_LO);
        sc->fc.config_rom[5] = 0;
        sc->fc.config_rom[0] = (4 << 24) | (5 << 16);

        sc->fc.config_rom[0] |= fw_crc16(&sc->fc.config_rom[1], 5*4);
#endif

/* SID receive buffer must align 2^11 */
#define OHCI_SIDSIZE    (1 << 11)
        sc->sid_buf = fwdma_alloc_setup(sc->fc.dev, sc->fc.dmat, OHCI_SIDSIZE,
            &sc->sid_dma, OHCI_SIDSIZE, BUS_DMA_NOWAIT);
        if (sc->sid_buf == NULL) {
                aprint_error_dev(sc->fc.dev, "sid_buf alloc failed.");
                return ENOMEM;
        }

        fwdma_alloc_setup(sc->fc.dev, sc->fc.dmat, sizeof(uint32_t),
            &sc->dummy_dma, sizeof(uint32_t), BUS_DMA_NOWAIT);
        if (sc->dummy_dma.v_addr == NULL) {
                aprint_error_dev(sc->fc.dev, "dummy_dma alloc failed.");
                return ENOMEM;
        }

        fwohci_db_init(sc, &sc->arrq);
        if ((sc->arrq.flags & FWOHCI_DBCH_INIT) == 0)
                return ENOMEM;

        fwohci_db_init(sc, &sc->arrs);
        if ((sc->arrs.flags & FWOHCI_DBCH_INIT) == 0)
                return ENOMEM;

        fwohci_db_init(sc, &sc->atrq);
        if ((sc->atrq.flags & FWOHCI_DBCH_INIT) == 0)
                return ENOMEM;

        fwohci_db_init(sc, &sc->atrs);
        if ((sc->atrs.flags & FWOHCI_DBCH_INIT) == 0)
                return ENOMEM;

        sc->fc.eui.hi = OREAD(sc, FWOHCIGUID_H);
        sc->fc.eui.lo = OREAD(sc, FWOHCIGUID_L);
        for (i = 0; i < 8; i++)
                ui[i] = FW_EUI64_BYTE(&sc->fc.eui, i);
        aprint_normal_dev(sc->fc.dev,
            "EUI64 %02x:%02x:%02x:%02x:%02x:%02x:%02x:%02x\n",
            ui[0], ui[1], ui[2], ui[3], ui[4], ui[5], ui[6], ui[7]);

        fwohci_reset(sc);

        sc->fc.bdev =
            config_found(sc->fc.dev, __UNCONST("ieee1394if"), fwohci_print,
            CFARGS_NONE);

        return 0;
}

int
fwohci_detach(struct fwohci_softc *sc, int flags)
{
        int i, rv;

        if (sc->fc.bdev != NULL) {
                rv = config_detach(sc->fc.bdev, flags);
                if (rv)
                        return rv;
        }
        if (sc->sid_buf != NULL)
                fwdma_free(sc->sid_dma.dma_tag, sc->sid_dma.dma_map,
                    sc->sid_dma.v_addr);
        if (sc->fc.config_rom != NULL)
                fwdma_free(sc->crom_dma.dma_tag, sc->crom_dma.dma_map,
                    sc->crom_dma.v_addr);

        fwohci_db_free(sc, &sc->arrq);
        fwohci_db_free(sc, &sc->arrs);
        fwohci_db_free(sc, &sc->atrq);
        fwohci_db_free(sc, &sc->atrs);
        for (i = 0; i < sc->fc.nisodma; i++) {
                fwohci_db_free(sc, &sc->it[i]);
                fwohci_db_free(sc, &sc->ir[i]);
        }

        fw_destroy_isodma(&sc->fc);
        fw_destroy(&sc->fc);

        return 0;
}

int
fwohci_intr(void *arg)
{
        struct fwohci_softc *sc = (struct fwohci_softc *)arg;
        uint32_t stat, irstat, itstat;

        if (!device_is_active(sc->fc.dev))
                return 0;

        if (!(sc->intmask & OHCI_INT_EN))
                /* polling mode? */
                return 0;

        stat = OREAD(sc, FWOHCI_INTSTAT);
        if (stat == 0xffffffff) {
                aprint_error_dev(sc->fc.dev, "device physically ejected?\n");
                return 0;
        }
        if (stat)
                OWRITE(sc, FWOHCI_INTSTATCLR, stat & ~OHCI_INT_PHY_BUS_R);

        stat &= sc->intmask;
        if (stat == 0)
                return 0;

        atomic_swap_32(&sc->intstat, stat);
        if (stat & OHCI_INT_DMA_IR) {
                irstat = OREAD(sc, OHCI_IR_STAT);
                OWRITE(sc, OHCI_IR_STATCLR, irstat);
                atomic_swap_32(&sc->irstat, irstat);
        }
        if (stat & OHCI_INT_DMA_IT) {
                itstat = OREAD(sc, OHCI_IT_STAT);
                OWRITE(sc, OHCI_IT_STATCLR, itstat);
                atomic_swap_32(&sc->itstat, itstat);
        }

        fwohci_intr_core(sc, stat);
        return 1;
}

int
fwohci_resume(struct fwohci_softc *sc)
{
        struct fw_xferq *ir;
        struct fw_bulkxfer *chunk;
        int i;
        extern int firewire_resume(struct firewire_comm *);

        fwohci_reset(sc);
        /* XXX resume isochronous receive automatically. (how about TX?) */
        for (i = 0; i < sc->fc.nisodma; i++) {
                ir = &sc->ir[i].xferq;
                if ((ir->flag & FWXFERQ_RUNNING) != 0) {
                        aprint_normal_dev(sc->fc.dev,
                            "resume iso receive ch: %d\n", i);
                        ir->flag &= ~FWXFERQ_RUNNING;
                        /* requeue stdma to stfree */
                        while ((chunk = STAILQ_FIRST(&ir->stdma)) != NULL) {
                                STAILQ_REMOVE_HEAD(&ir->stdma, link);
                                STAILQ_INSERT_TAIL(&ir->stfree, chunk, link);
                        }
                        sc->fc.irx_enable(&sc->fc, i);
                }
        }

        firewire_resume(&sc->fc);
        sc->fc.ibr(&sc->fc);
        return 0;
}

int
fwohci_stop(struct fwohci_softc *sc)
{
        u_int i;

        fwohci_set_intr(&sc->fc, 0);

/* Now stopping all DMA channel */
        OWRITE(sc, OHCI_ARQCTLCLR, OHCI_CNTL_DMA_RUN);
        OWRITE(sc, OHCI_ARSCTLCLR, OHCI_CNTL_DMA_RUN);
        OWRITE(sc, OHCI_ATQCTLCLR, OHCI_CNTL_DMA_RUN);
        OWRITE(sc, OHCI_ATSCTLCLR, OHCI_CNTL_DMA_RUN);

        for (i = 0; i < sc->fc.nisodma; i++) {
                OWRITE(sc, OHCI_IRCTLCLR(i), OHCI_CNTL_DMA_RUN);
                OWRITE(sc, OHCI_ITCTLCLR(i), OHCI_CNTL_DMA_RUN);
        }

#if 0 /* Let dcons(4) be accessed */
/* Stop interrupt */
        OWRITE(sc, FWOHCI_INTMASKCLR,
            OHCI_INT_EN |
            OHCI_INT_ERR |
            OHCI_INT_PHY_SID |
            OHCI_INT_PHY_INT |
            OHCI_INT_DMA_ATRQ |
            OHCI_INT_DMA_ATRS |
            OHCI_INT_DMA_PRRQ |
            OHCI_INT_DMA_PRRS |
            OHCI_INT_DMA_ARRQ |
            OHCI_INT_DMA_ARRS |
            OHCI_INT_PHY_BUS_R);

/* FLUSH FIFO and reset Transmitter/Receiver */
        OWRITE(sc, OHCI_HCCCTL, OHCI_HCC_RESET);
#endif

/* XXX Link down?  Bus reset? */
        return 0;
}


static int
fwohci_ioctl(dev_t dev, u_long cmd, void *data, int flag, struct lwp *td)
{
        struct fwohci_softc *sc;
        struct fw_reg_req_t *reg = (struct fw_reg_req_t *)data;
        uint32_t *dmach = (uint32_t *)data;
        int err = 0;

        sc = device_lookup_private(&fwohci_cd, DEV2UNIT(dev));
        if (sc == NULL)
                return ENXIO;

        if (!data)
                return EINVAL;

        switch (cmd) {
        case FWOHCI_WRREG:
#define OHCI_MAX_REG 0x800
                if (reg->addr <= OHCI_MAX_REG) {
                        OWRITE(sc, reg->addr, reg->data);
                        reg->data = OREAD(sc, reg->addr);
                } else
                        err = EINVAL;
                break;

        case FWOHCI_RDREG:
                if (reg->addr <= OHCI_MAX_REG)
                        reg->data = OREAD(sc, reg->addr);
                else
                        err = EINVAL;
                break;

/* Read DMA descriptors for debug  */
        case DUMPDMA:
                if (*dmach <= OHCI_MAX_DMA_CH) {
                        dump_dma(sc, *dmach);
                        dump_db(sc, *dmach);
                } else
                        err = EINVAL;
                break;

/* Read/Write Phy registers */
#define OHCI_MAX_PHY_REG 0xf
        case FWOHCI_RDPHYREG:
                if (reg->addr <= OHCI_MAX_PHY_REG)
                        reg->data = fwphy_rddata(sc, reg->addr);
                else
                        err = EINVAL;
                break;

        case FWOHCI_WRPHYREG:
                if (reg->addr <= OHCI_MAX_PHY_REG)
                        reg->data = fwphy_wrdata(sc, reg->addr, reg->data);
                else
                        err = EINVAL;
                break;

        default:
                err = EINVAL;
                break;
        }
        return err;
}

int
fwohci_print(void *aux, const char *pnp)
{
        struct fw_attach_args *fwa = (struct fw_attach_args *)aux;

        if (pnp)
                aprint_normal("%s at %s", fwa->name, pnp);

        return UNCONF;
}


static uint32_t
fwohci_cyctimer(struct firewire_comm *fc)
{
        struct fwohci_softc *sc = (struct fwohci_softc *)fc;

        return OREAD(sc, OHCI_CYCLETIMER);
}

static uint32_t
fwohci_set_bus_manager(struct firewire_comm *fc, u_int node)
{
        struct fwohci_softc *sc = (struct fwohci_softc *)fc;
        uint32_t bm;
        int i;

#define OHCI_CSR_DATA   0x0c
#define OHCI_CSR_COMP   0x10
#define OHCI_CSR_CONT   0x14
#define OHCI_BUS_MANAGER_ID     0

        OWRITE(sc, OHCI_CSR_DATA, node);
        OWRITE(sc, OHCI_CSR_COMP, 0x3f);
        OWRITE(sc, OHCI_CSR_CONT, OHCI_BUS_MANAGER_ID);
        for (i = 0; !(OREAD(sc, OHCI_CSR_CONT) & (1U <<31)) && (i < 1000); i++)
                DELAY(10);
        bm = OREAD(sc, OHCI_CSR_DATA);
        if ((bm & 0x3f) == 0x3f)
                bm = node;
        if (firewire_debug)
                printf("fw_set_bus_manager: %d->%d (loop=%d)\n", bm, node, i);

        return bm;
}

static void
fwohci_ibr(struct firewire_comm *fc)
{
        struct fwohci_softc *sc = (struct fwohci_softc *)fc;
        uint32_t fun;

        aprint_normal_dev(fc->dev, "Initiate bus reset\n");

        /*
         * Make sure our cached values from the config rom are
         * initialised.
         */
        OWRITE(sc, OHCI_CROMHDR, ntohl(sc->fc.config_rom[0]));
        OWRITE(sc, OHCI_BUS_OPT, ntohl(sc->fc.config_rom[2]));

        /*
         * Set root hold-off bit so that non cyclemaster capable node
         * shouldn't became the root node.
         */
#if 1
        fun = fwphy_rddata(sc, FW_PHY_IBR_REG);
        fun |= FW_PHY_IBR | FW_PHY_RHB;
        fun = fwphy_wrdata(sc, FW_PHY_IBR_REG, fun);
#else   /* Short bus reset */
        fun = fwphy_rddata(sc, FW_PHY_ISBR_REG);
        fun |= FW_PHY_ISBR | FW_PHY_RHB;
        fun = fwphy_wrdata(sc, FW_PHY_ISBR_REG, fun);
#endif
}

static int
fwohci_irx_enable(struct firewire_comm *fc, int dmach)
{
        struct fwohci_softc *sc = (struct fwohci_softc *)fc;
        struct fwohci_dbch *dbch;
        struct fwohcidb_tr *db_tr;
        struct fw_bulkxfer *first, *prev, *chunk, *txfer;
        struct fw_xferq *ir;
        uint32_t stat;
        unsigned short tag, ich;
        int err = 0, ldesc;

        dbch = &sc->ir[dmach];
        ir = &dbch->xferq;

        if ((ir->flag & FWXFERQ_RUNNING) == 0) {
                tag = (ir->flag >> 6) & 3;
                ich = ir->flag & 0x3f;
                OWRITE(sc, OHCI_IRMATCH(dmach), tagbit[tag] | ich);

                ir->queued = 0;
                dbch->ndb = ir->bnpacket * ir->bnchunk;
                dbch->ndesc = 2;
                fwohci_db_init(sc, dbch);
                if ((dbch->flags & FWOHCI_DBCH_INIT) == 0)
                        return ENOMEM;
                err = fwohci_rx_enable(sc, dbch);
                if (err)
                        return err;
        }

        first = STAILQ_FIRST(&ir->stfree);
        if (first == NULL) {
                aprint_error_dev(fc->dev, "IR DMA no free chunk\n");
                return 0;
        }

        ldesc = dbch->ndesc - 1;
        prev = NULL;
        STAILQ_FOREACH(txfer, &ir->stdma, link)
                prev = txfer;
        while ((chunk = STAILQ_FIRST(&ir->stfree)) != NULL) {
                struct fwohcidb *db;

                if (chunk->mbuf != NULL) {
                        db_tr = (struct fwohcidb_tr *)(chunk->start);
                        db_tr->dbcnt = 1;
                        err = bus_dmamap_load_mbuf(fc->dmat, db_tr->dma_map,
                            chunk->mbuf, BUS_DMA_NOWAIT);
                        if (err == 0)
                                fwohci_execute_db(db_tr, db_tr->dma_map);
                        else
                                aprint_error_dev(fc->dev,
                                    "mbuf load failed: %d\n", err);
                        FWOHCI_DMA_SET(db_tr->db[1].db.desc.cmd,
                            OHCI_UPDATE |
                            OHCI_INPUT_LAST |
                            OHCI_INTERRUPT_ALWAYS |
                            OHCI_BRANCH_ALWAYS);
                }
                db = ((struct fwohcidb_tr *)(chunk->end))->db;
                FWOHCI_DMA_WRITE(db[ldesc].db.desc.res, 0);
                FWOHCI_DMA_CLEAR(db[ldesc].db.desc.depend, 0xf);
                if (prev != NULL) {
                        db = ((struct fwohcidb_tr *)(prev->end))->db;
                        FWOHCI_DMA_SET(db[ldesc].db.desc.depend, dbch->ndesc);
                }
                STAILQ_REMOVE_HEAD(&ir->stfree, link);
                STAILQ_INSERT_TAIL(&ir->stdma, chunk, link);
                prev = chunk;
        }
        fwdma_sync_multiseg_all(dbch->am,
            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
        stat = OREAD(sc, OHCI_IRCTL(dmach));
        if (stat & OHCI_CNTL_DMA_ACTIVE)
                return 0;
        if (stat & OHCI_CNTL_DMA_RUN) {
                OWRITE(sc, OHCI_IRCTLCLR(dmach), OHCI_CNTL_DMA_RUN);
                aprint_error_dev(fc->dev, "IR DMA overrun (0x%08x)\n", stat);
        }

        if (firewire_debug)
                printf("start IR DMA 0x%x\n", stat);
        OWRITE(sc, OHCI_IR_MASKCLR, 1 << dmach);
        OWRITE(sc, OHCI_IR_STATCLR, 1 << dmach);
        OWRITE(sc, OHCI_IR_MASK, 1 << dmach);
        OWRITE(sc, OHCI_IRCTLCLR(dmach), 0xf0000000);
        OWRITE(sc, OHCI_IRCTL(dmach), OHCI_CNTL_ISOHDR);
        OWRITE(sc, OHCI_IRCMD(dmach),
            ((struct fwohcidb_tr *)(first->start))->bus_addr | dbch->ndesc);
        OWRITE(sc, OHCI_IRCTL(dmach), OHCI_CNTL_DMA_RUN);
        OWRITE(sc, FWOHCI_INTMASK, OHCI_INT_DMA_IR);
#if 0
        dump_db(sc, IRX_CH + dmach);
#endif
        return err;
}

static int
fwohci_irx_disable(struct firewire_comm *fc, int dmach)
{
        struct fwohci_softc *sc = (struct fwohci_softc *)fc;

        OWRITE(sc, OHCI_IRCTLCLR(dmach), OHCI_CNTL_DMA_RUN);
        OWRITE(sc, OHCI_IR_MASKCLR, 1 << dmach);
        OWRITE(sc, OHCI_IR_STATCLR, 1 << dmach);
        /* XXX we cannot free buffers until the DMA really stops */
        kpause("fwirxd", true, hz, NULL);
        fwohci_db_free(sc, &sc->ir[dmach]);
        sc->ir[dmach].xferq.flag &= ~FWXFERQ_RUNNING;
        return 0;
}


static int
fwohci_itxbuf_enable(struct firewire_comm *fc, int dmach)
{
        struct fwohci_softc *sc = (struct fwohci_softc *)fc;
        struct fwohci_dbch *dbch;
        struct fw_bulkxfer *first, *chunk, *prev, *txfer;
        struct fw_xferq *it;
        uint32_t stat;
        int cycle_match, cycle_now, ldesc, err = 0;

        dbch = &sc->it[dmach];
        it = &dbch->xferq;

        if ((dbch->flags & FWOHCI_DBCH_INIT) == 0) {
                dbch->ndb = it->bnpacket * it->bnchunk;
                dbch->ndesc = 3;
                fwohci_db_init(sc, dbch);
                if ((dbch->flags & FWOHCI_DBCH_INIT) == 0)
                        return ENOMEM;

                err = fwohci_tx_enable(sc, dbch);
                if (err)
                        return err;
        }

        ldesc = dbch->ndesc - 1;
        prev = NULL;
        STAILQ_FOREACH(txfer, &it->stdma, link)
                prev = txfer;
        while ((chunk = STAILQ_FIRST(&it->stvalid)) != NULL) {
                struct fwohcidb *db;

                fwdma_sync_multiseg(it->buf, chunk->poffset, it->bnpacket,
                    BUS_DMASYNC_PREWRITE);
                fwohci_txbufdb(sc, dmach, chunk);
                if (prev != NULL) {
                        db = ((struct fwohcidb_tr *)(prev->end))->db;
#if 0 /* XXX necessary? */
                        FWOHCI_DMA_SET(db[ldesc].db.desc.cmd,
                            OHCI_BRANCH_ALWAYS);
#endif
#if 0 /* if bulkxfer->npacket changes */
                        db[ldesc].db.desc.depend = db[0].db.desc.depend =
                            ((struct fwohcidb_tr *)(chunk->start))->bus_addr |
                                                                dbch->ndesc;
#else
                        FWOHCI_DMA_SET(db[0].db.desc.depend, dbch->ndesc);
                        FWOHCI_DMA_SET(db[ldesc].db.desc.depend, dbch->ndesc);
#endif
                }
                STAILQ_REMOVE_HEAD(&it->stvalid, link);
                STAILQ_INSERT_TAIL(&it->stdma, chunk, link);
                prev = chunk;
        }
        fwdma_sync_multiseg_all(dbch->am,
            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
        stat = OREAD(sc, OHCI_ITCTL(dmach));
        if (firewire_debug && (stat & OHCI_CNTL_CYCMATCH_S))
                printf("stat 0x%x\n", stat);

        if (stat & (OHCI_CNTL_DMA_ACTIVE | OHCI_CNTL_CYCMATCH_S))
                return 0;

#if 0
        OWRITE(sc, OHCI_ITCTLCLR(dmach), OHCI_CNTL_DMA_RUN);
#endif
        OWRITE(sc, OHCI_IT_MASKCLR, 1 << dmach);
        OWRITE(sc, OHCI_IT_STATCLR, 1 << dmach);
        OWRITE(sc, OHCI_IT_MASK, 1 << dmach);
        OWRITE(sc, FWOHCI_INTMASK, OHCI_INT_DMA_IT);

        first = STAILQ_FIRST(&it->stdma);
        OWRITE(sc, OHCI_ITCMD(dmach),
            ((struct fwohcidb_tr *)(first->start))->bus_addr | dbch->ndesc);
        if (firewire_debug > 1) {
                printf("fwohci_itxbuf_enable: kick 0x%08x\n", stat);
#if 1
                dump_dma(sc, ITX_CH + dmach);
#endif
        }
        if ((stat & OHCI_CNTL_DMA_RUN) == 0) {
#if 1
                /* Don't start until all chunks are buffered */
                if (STAILQ_FIRST(&it->stfree) != NULL)
                        goto out;
#endif
#if 1
                /* Clear cycle match counter bits */
                OWRITE(sc, OHCI_ITCTLCLR(dmach), 0xffff0000);

                /* 2bit second + 13bit cycle */
                cycle_now = (fc->cyctimer(fc) >> 12) & 0x7fff;
                cycle_match = fwohci_next_cycle(sc, cycle_now);

                OWRITE(sc, OHCI_ITCTL(dmach),
                    OHCI_CNTL_CYCMATCH_S | (cycle_match << 16) |
                                                        OHCI_CNTL_DMA_RUN);
#else
                OWRITE(sc, OHCI_ITCTL(dmach), OHCI_CNTL_DMA_RUN);
#endif
                if (firewire_debug > 1) {
                        printf("cycle_match: 0x%04x->0x%04x\n",
                            cycle_now, cycle_match);
                        dump_dma(sc, ITX_CH + dmach);
                        dump_db(sc, ITX_CH + dmach);
                }
        } else if ((stat & OHCI_CNTL_CYCMATCH_S) == 0) {
                aprint_error_dev(fc->dev, "IT DMA underrun (0x%08x)\n", stat);
                OWRITE(sc, OHCI_ITCTL(dmach), OHCI_CNTL_DMA_WAKE);
        }
out:
        return err;
}

static int
fwohci_itx_disable(struct firewire_comm *fc, int dmach)
{
        struct fwohci_softc *sc = (struct fwohci_softc *)fc;

        OWRITE(sc, OHCI_ITCTLCLR(dmach),
            OHCI_CNTL_DMA_RUN | OHCI_CNTL_CYCMATCH_S);
        OWRITE(sc, OHCI_IT_MASKCLR, 1 << dmach);
        OWRITE(sc, OHCI_IT_STATCLR, 1 << dmach);
        /* XXX we cannot free buffers until the DMA really stops */
        kpause("fwitxd", true, hz, NULL);
        fwohci_db_free(sc, &sc->it[dmach]);
        sc->it[dmach].xferq.flag &= ~FWXFERQ_RUNNING;
        return 0;
}

static void
fwohci_timeout(struct firewire_comm *fc)
{
#if 0
        struct fwohci_softc *sc = (struct fwohci_softc *)fc;
#endif
        /* nothing? */
}

#if BYTE_ORDER == BIG_ENDIAN
static void
fwohci_irx_post (struct firewire_comm *fc, uint32_t *qld)
{

        qld[0] = FWOHCI_DMA_READ(qld[0]);
        return;
}
#endif

static void
fwohci_set_intr(struct firewire_comm *fc, int enable)
{
        struct fwohci_softc *sc = (struct fwohci_softc *)fc;

        if (firewire_debug)
                printf("fwohci_set_intr: %d\n", enable);
        if (enable) {
                sc->intmask |= OHCI_INT_EN;
                OWRITE(sc, FWOHCI_INTMASK, OHCI_INT_EN);
        } else {
                sc->intmask &= ~OHCI_INT_EN;
                OWRITE(sc, FWOHCI_INTMASKCLR, OHCI_INT_EN);
        }
}

/*
 * Communication with PHY device
 */
/* XXX need lock for phy access */
static uint32_t
fwphy_rddata(struct fwohci_softc *sc, u_int addr)
{
        uint32_t fun, stat;
        u_int i, retry = 0;

        addr &= 0xf;
#define MAX_RETRY 100
again:
        OWRITE(sc, FWOHCI_INTSTATCLR, OHCI_INT_REG_FAIL);
        fun = PHYDEV_RDCMD | (addr << PHYDEV_REGADDR);
        OWRITE(sc, OHCI_PHYACCESS, fun);
        for (i = 0; i < MAX_RETRY; i++) {
                fun = OREAD(sc, OHCI_PHYACCESS);
                if ((fun & PHYDEV_RDCMD) == 0 && (fun & PHYDEV_RDDONE) != 0)
                        break;
                DELAY(100);
        }
        if (i >= MAX_RETRY) {
                if (firewire_debug)
                        printf("phy read failed(1).\n");
                if (++retry < MAX_RETRY) {
                        DELAY(100);
                        goto again;
                }
        }
        /* Make sure that SCLK is started */
        stat = OREAD(sc, FWOHCI_INTSTAT);
        if ((stat & OHCI_INT_REG_FAIL) != 0 ||
            ((fun >> PHYDEV_REGADDR) & 0xf) != addr) {
                if (firewire_debug)
                        printf("phy read failed(2).\n");
                if (++retry < MAX_RETRY) {
                        DELAY(100);
                        goto again;
                }
        }
        if (firewire_debug || retry >= MAX_RETRY)
                aprint_error_dev(sc->fc.dev,
                    "fwphy_rddata: 0x%x loop=%d, retry=%d\n",
                    addr, i, retry);
#undef MAX_RETRY
        return (fun >> PHYDEV_RDDATA) & 0xff;
}

static uint32_t
fwphy_wrdata(struct fwohci_softc *sc, uint32_t addr, uint32_t data)
{
        uint32_t fun;

        addr &= 0xf;
        data &= 0xff;

        fun =
            (PHYDEV_WRCMD | (addr << PHYDEV_REGADDR) | (data << PHYDEV_WRDATA));
        OWRITE(sc, OHCI_PHYACCESS, fun);
        DELAY(100);

        return fwphy_rddata(sc, addr);
}

static int
fwohci_probe_phy(struct fwohci_softc *sc)
{
        uint32_t reg, reg2;
        int e1394a = 1;

/*
 * probe PHY parameters
 * 0. to prove PHY version, whether compliance of 1394a.
 * 1. to probe maximum speed supported by the PHY and
 *    number of port supported by core-logic.
 *    It is not actually available port on your PC .
 */
        OWRITE(sc, OHCI_HCCCTL, OHCI_HCC_LPS);
        DELAY(500);

        reg = fwphy_rddata(sc, FW_PHY_SPD_REG);

        if ((reg >> 5) != 7) {
                sc->fc.mode &= ~FWPHYASYST;
                sc->fc.nport = reg & FW_PHY_NP;
                sc->fc.speed = reg & FW_PHY_SPD >> 6;
                if (sc->fc.speed > MAX_SPEED) {
                        aprint_error_dev(sc->fc.dev,
                            "invalid speed %d (fixed to %d).\n",
                            sc->fc.speed, MAX_SPEED);
                        sc->fc.speed = MAX_SPEED;
                }
                aprint_normal_dev(sc->fc.dev, "Phy 1394 only %s, %d ports.\n",
                    fw_linkspeed[sc->fc.speed], sc->fc.nport);
        } else {
                reg2 = fwphy_rddata(sc, FW_PHY_ESPD_REG);
                sc->fc.mode |= FWPHYASYST;
                sc->fc.nport = reg & FW_PHY_NP;
                sc->fc.speed = (reg2 & FW_PHY_ESPD) >> 5;
                if (sc->fc.speed > MAX_SPEED) {
                        aprint_error_dev(sc->fc.dev,
                            "invalid speed %d (fixed to %d).\n",
                            sc->fc.speed, MAX_SPEED);
                        sc->fc.speed = MAX_SPEED;
                }
                aprint_normal_dev(sc->fc.dev,
                    "Phy 1394a available %s, %d ports.\n",
                    fw_linkspeed[sc->fc.speed], sc->fc.nport);

                /* check programPhyEnable */
                reg2 = fwphy_rddata(sc, 5);
#if 0
                if (e1394a && (OREAD(sc, OHCI_HCCCTL) & OHCI_HCC_PRPHY)) {
#else   /* XXX force to enable 1394a */
                if (e1394a) {
#endif
                        if (firewire_debug)
                                printf("Enable 1394a Enhancements\n");
                        /* enable EAA EMC */
                        reg2 |= 0x03;
                        /* set aPhyEnhanceEnable */
                        OWRITE(sc, OHCI_HCCCTL, OHCI_HCC_PHYEN);
                        OWRITE(sc, OHCI_HCCCTLCLR, OHCI_HCC_PRPHY);
                }
#if 0
                else {
                        /* for safe */
                        reg2 &= ~0x83;
                }
#endif
                reg2 = fwphy_wrdata(sc, 5, reg2);
        }

        reg = fwphy_rddata(sc, FW_PHY_SPD_REG);
        if ((reg >> 5) == 7) {
                reg = fwphy_rddata(sc, 4);
                reg |= 1 << 6;
                fwphy_wrdata(sc, 4, reg);
                reg = fwphy_rddata(sc, 4);
        }
        return 0;
}

static void
fwohci_reset(struct fwohci_softc *sc)
{
        struct fwohcidb_tr *db_tr;
        uint32_t reg, reg2;
        int i, max_rec, speed;

        /* Disable interrupts */
        OWRITE(sc, FWOHCI_INTMASKCLR, ~0);

        /* Now stopping all DMA channels */
        OWRITE(sc, OHCI_ARQCTLCLR, OHCI_CNTL_DMA_RUN);
        OWRITE(sc, OHCI_ARSCTLCLR, OHCI_CNTL_DMA_RUN);
        OWRITE(sc, OHCI_ATQCTLCLR, OHCI_CNTL_DMA_RUN);
        OWRITE(sc, OHCI_ATSCTLCLR, OHCI_CNTL_DMA_RUN);

        OWRITE(sc, OHCI_IR_MASKCLR, ~0);
        for (i = 0; i < sc->fc.nisodma; i++) {
                OWRITE(sc, OHCI_IRCTLCLR(i), OHCI_CNTL_DMA_RUN);
                OWRITE(sc, OHCI_ITCTLCLR(i), OHCI_CNTL_DMA_RUN);
        }

        /* FLUSH FIFO and reset Transmitter/Receiver */
        OWRITE(sc, OHCI_HCCCTL, OHCI_HCC_RESET);
        if (firewire_debug)
                printf("resetting OHCI...");
        i = 0;
        while (OREAD(sc, OHCI_HCCCTL) & OHCI_HCC_RESET) {
                if (i++ > 100)
                        break;
                DELAY(1000);
        }
        if (firewire_debug)
                printf("done (loop=%d)\n", i);

        /* Probe phy */
        fwohci_probe_phy(sc);

        /* Probe link */
        reg = OREAD(sc, OHCI_BUS_OPT);
        reg2 = reg | OHCI_BUSFNC;
        max_rec = (reg & 0x0000f000) >> 12;
        speed = (reg & 0x00000007);
        aprint_normal_dev(sc->fc.dev, "Link %s, max_rec %d bytes.\n",
            fw_linkspeed[speed], MAXREC(max_rec));
        /* XXX fix max_rec */
        sc->fc.maxrec = sc->fc.speed + 8;
        if (max_rec != sc->fc.maxrec) {
                reg2 = (reg2 & 0xffff0fff) | (sc->fc.maxrec << 12);
                aprint_normal_dev(sc->fc.dev, "max_rec %d -> %d\n",
                    MAXREC(max_rec), MAXREC(sc->fc.maxrec));
        }
        if (firewire_debug)
                printf("BUS_OPT 0x%x -> 0x%x\n", reg, reg2);
        OWRITE(sc, OHCI_BUS_OPT, reg2);

        /* Initialize registers */
        OWRITE(sc, OHCI_CROMHDR, sc->fc.config_rom[0]);
        OWRITE(sc, OHCI_CROMPTR, sc->crom_dma.bus_addr);
        OWRITE(sc, OHCI_HCCCTLCLR, OHCI_HCC_BIGEND);
        OWRITE(sc, OHCI_HCCCTL, OHCI_HCC_POSTWR);
        OWRITE(sc, OHCI_SID_BUF, sc->sid_dma.bus_addr);
        OWRITE(sc, OHCI_LNKCTL, OHCI_CNTL_SID);

        /* Enable link */
        OWRITE(sc, OHCI_HCCCTL, OHCI_HCC_LINKEN);

        /* Force to start async RX DMA */
        sc->arrq.xferq.flag &= ~FWXFERQ_RUNNING;
        sc->arrs.xferq.flag &= ~FWXFERQ_RUNNING;
        fwohci_rx_enable(sc, &sc->arrq);
        fwohci_rx_enable(sc, &sc->arrs);

        /* Initialize async TX */
        OWRITE(sc, OHCI_ATQCTLCLR, OHCI_CNTL_DMA_RUN | OHCI_CNTL_DMA_DEAD);
        OWRITE(sc, OHCI_ATSCTLCLR, OHCI_CNTL_DMA_RUN | OHCI_CNTL_DMA_DEAD);

        /* AT Retries */
        OWRITE(sc, FWOHCI_RETRY,
            /* CycleLimit   PhyRespRetries ATRespRetries ATReqRetries */
            (0xffffU << 16) | (0x0f << 8) | (0x0f << 4) | 0x0f);

        sc->atrq.top = STAILQ_FIRST(&sc->atrq.db_trq);
        sc->atrs.top = STAILQ_FIRST(&sc->atrs.db_trq);
        sc->atrq.bottom = sc->atrq.top;
        sc->atrs.bottom = sc->atrs.top;

        for (i = 0, db_tr = sc->atrq.top; i < sc->atrq.ndb;
            i++, db_tr = STAILQ_NEXT(db_tr, link))
                db_tr->xfer = NULL;
        for (i = 0, db_tr = sc->atrs.top; i < sc->atrs.ndb;
            i++, db_tr = STAILQ_NEXT(db_tr, link))
                db_tr->xfer = NULL;


        /* Enable interrupts */
        sc->intmask =  (OHCI_INT_ERR | OHCI_INT_PHY_SID
                        | OHCI_INT_DMA_ATRQ | OHCI_INT_DMA_ATRS
                        | OHCI_INT_DMA_PRRQ | OHCI_INT_DMA_PRRS
                        | OHCI_INT_PHY_BUS_R | OHCI_INT_PW_ERR);
        sc->intmask |= OHCI_INT_DMA_IR | OHCI_INT_DMA_IT;
        sc->intmask |= OHCI_INT_CYC_LOST | OHCI_INT_PHY_INT;
        OWRITE(sc, FWOHCI_INTMASK, sc->intmask);
        fwohci_set_intr(&sc->fc, 1);
}

#define LAST_DB(dbtr) \
        &dbtr->db[(dbtr->dbcnt > 2) ? (dbtr->dbcnt - 1) : 0];

static void
fwohci_execute_db(struct fwohcidb_tr *db_tr, bus_dmamap_t dmamap)
{
        struct fwohcidb *db;
        bus_dma_segment_t *s;
        int i;

        db = &db_tr->db[db_tr->dbcnt];
        for (i = 0; i < dmamap->dm_nsegs; i++) {
                s = &dmamap->dm_segs[i];
                FWOHCI_DMA_WRITE(db->db.desc.addr, s->ds_addr);
                FWOHCI_DMA_WRITE(db->db.desc.cmd, s->ds_len);
                FWOHCI_DMA_WRITE(db->db.desc.res, 0);
                db++;
                db_tr->dbcnt++;
        }
}

static void
fwohci_start(struct fwohci_softc *sc, struct fwohci_dbch *dbch)
{
        struct fw_xfer *xfer;
        struct fw_pkt *fp;
        struct fwohci_txpkthdr *ohcifp;
        struct fwohcidb_tr *db_tr, *kick;
        struct fwohcidb *db;
        uint32_t *ld;
        int tcode, hdr_len, pl_off, fsegment = -1, i;
        const struct tcode_info *info;
        static int maxdesc = 0;

        KASSERT(mutex_owned(&dbch->xferq.q_mtx));

#if DIAGNOSTIC
        if (dbch->off != OHCI_ATQOFF &&
            dbch->off != OHCI_ATSOFF)
                panic("not async tx");
#endif

        if (dbch->flags & FWOHCI_DBCH_FULL)
                return;

        db_tr = dbch->top;
        kick = db_tr;
        if (dbch->pdb_tr != NULL) {
                kick = dbch->pdb_tr;
                fwdma_sync_multiseg(dbch->am, kick->idx, kick->idx,
                    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
        }
txloop:
        xfer = STAILQ_FIRST(&dbch->xferq.q);
        if (xfer == NULL)
                goto kick;
#if 0
        if (dbch->xferq.queued == 0)
                aprint_error_dev(sc->fc.dev, "TX queue empty\n");
#endif
        STAILQ_REMOVE_HEAD(&dbch->xferq.q, link);
        db_tr->xfer = xfer;
        xfer->flag = FWXF_START;

        fp = &xfer->send.hdr;
        tcode = fp->mode.common.tcode;

        ohcifp = (struct fwohci_txpkthdr *) db_tr->db[1].db.immed;
        info = &tinfo[tcode];
        hdr_len = pl_off = info->hdr_len;

        ld = ohcifp->mode.ld;
        ld[0] = ld[1] = ld[2] = ld[3] = 0;
        for (i = 0; i < pl_off / 4; i++)
                ld[i] = fp->mode.ld[i];

        ohcifp->mode.common.spd = xfer->send.spd & 0x7;
        if (tcode == FWTCODE_STREAM) {
                hdr_len = 8;
                ohcifp->mode.stream.len = fp->mode.stream.len;
        } else if (tcode == FWTCODE_PHY) {
                hdr_len = 12;
                ld[1] = fp->mode.ld[1];
                ld[2] = fp->mode.ld[2];
                ohcifp->mode.common.spd = 0;
                ohcifp->mode.common.tcode = FWOHCITCODE_PHY;
        } else {
                ohcifp->mode.asycomm.dst = fp->mode.hdr.dst;
                ohcifp->mode.asycomm.srcbus = OHCI_ASYSRCBUS;
                ohcifp->mode.asycomm.tlrt |= FWRETRY_X;
        }
        db = db_tr->db;
        FWOHCI_DMA_WRITE(db->db.desc.cmd,
            OHCI_OUTPUT_MORE | OHCI_KEY_ST2 | hdr_len);
        FWOHCI_DMA_WRITE(db->db.desc.addr, 0);
        FWOHCI_DMA_WRITE(db->db.desc.res, 0);
/* Specify bound timer of asy. response */
        if (dbch->off != OHCI_ATSOFF)
                FWOHCI_DMA_WRITE(db->db.desc.res,
                     (OREAD(sc, OHCI_CYCLETIMER) >> 12) + (1 << 13));
#if BYTE_ORDER == BIG_ENDIAN
        if (tcode == FWTCODE_WREQQ || tcode == FWTCODE_RRESQ)
                hdr_len = 12;
        for (i = 0; i < hdr_len / 4; i++)
                FWOHCI_DMA_WRITE(ld[i], ld[i]);
#endif

again:
        db_tr->dbcnt = 2;
        db = &db_tr->db[db_tr->dbcnt];
        if (xfer->send.pay_len > 0) {
                int err;
                /* handle payload */
                if (xfer->mbuf == NULL)
                        err = bus_dmamap_load(sc->fc.dmat, db_tr->dma_map,
                            xfer->send.payload, xfer->send.pay_len, NULL,
                            BUS_DMA_WAITOK);
                else {
                        /* XXX we can handle only 6 (=8-2) mbuf chains */
                        err = bus_dmamap_load_mbuf(sc->fc.dmat, db_tr->dma_map,
                            xfer->mbuf, BUS_DMA_WAITOK);
                        if (err == EFBIG) {
                                struct mbuf *m0;

                                if (firewire_debug)
                                        printf("EFBIG.\n");
                                m0 = m_getcl(M_DONTWAIT, MT_DATA, M_PKTHDR);
                                if (m0 != NULL) {
                                        m_copydata(xfer->mbuf, 0,
                                            xfer->mbuf->m_pkthdr.len,
                                            mtod(m0, void *));
                                        m0->m_len = m0->m_pkthdr.len =
                                            xfer->mbuf->m_pkthdr.len;
                                        m_freem(xfer->mbuf);
                                        xfer->mbuf = m0;
                                        goto again;
                                }
                                aprint_error_dev(sc->fc.dev,
                                    "m_getcl failed.\n");
                        }
                }
                if (!err)
                        fwohci_execute_db(db_tr, db_tr->dma_map);
                else
                        aprint_error_dev(sc->fc.dev,
                            "dmamap_load: err=%d\n", err);
                bus_dmamap_sync(sc->fc.dmat, db_tr->dma_map,
                    0, db_tr->dma_map->dm_mapsize, BUS_DMASYNC_PREWRITE);
#if 0 /* OHCI_OUTPUT_MODE == 0 */
                for (i = 2; i < db_tr->dbcnt; i++)
                        FWOHCI_DMA_SET(db_tr->db[i].db.desc.cmd,
                            OHCI_OUTPUT_MORE);
#endif
        }
        if (maxdesc < db_tr->dbcnt) {
                maxdesc = db_tr->dbcnt;
                if (firewire_debug)
                        printf("maxdesc: %d\n", maxdesc);
        }
        /* last db */
        db = LAST_DB(db_tr);
        FWOHCI_DMA_SET(db->db.desc.cmd,
            OHCI_OUTPUT_LAST | OHCI_INTERRUPT_ALWAYS | OHCI_BRANCH_ALWAYS);
        FWOHCI_DMA_WRITE(db->db.desc.depend,
            STAILQ_NEXT(db_tr, link)->bus_addr);

        if (fsegment == -1)
                fsegment = db_tr->dbcnt;
        if (dbch->pdb_tr != NULL) {
                db = LAST_DB(dbch->pdb_tr);
                FWOHCI_DMA_SET(db->db.desc.depend, db_tr->dbcnt);
        }
        dbch->xferq.queued++;
        dbch->pdb_tr = db_tr;
        db_tr = STAILQ_NEXT(db_tr, link);
        if (db_tr != dbch->bottom)
                goto txloop;
        else {
                aprint_error_dev(sc->fc.dev, "fwohci_start: lack of db_trq\n");
                dbch->flags |= FWOHCI_DBCH_FULL;
        }
kick:
        /* kick asy q */
        fwdma_sync_multiseg(dbch->am, kick->idx, dbch->pdb_tr->idx,
            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);

        if (dbch->xferq.flag & FWXFERQ_RUNNING)
                OWRITE(sc, OHCI_DMACTL(dbch->off), OHCI_CNTL_DMA_WAKE);
        else {
                if (firewire_debug)
                        printf("start AT DMA status=%x\n",
                            OREAD(sc, OHCI_DMACTL(dbch->off)));
                OWRITE(sc, OHCI_DMACMD(dbch->off),
                    dbch->top->bus_addr | fsegment);
                OWRITE(sc, OHCI_DMACTL(dbch->off), OHCI_CNTL_DMA_RUN);
                dbch->xferq.flag |= FWXFERQ_RUNNING;
        }

        dbch->top = db_tr;
        return;
}

static void
fwohci_start_atq(struct firewire_comm *fc)
{
        struct fwohci_softc *sc = (struct fwohci_softc *)fc;
        struct fwohci_dbch *dbch = &sc->atrq;

        mutex_enter(&dbch->xferq.q_mtx);
        fwohci_start(sc, dbch);
        mutex_exit(&dbch->xferq.q_mtx);
        return;
}

static void
fwohci_start_ats(struct firewire_comm *fc)
{
        struct fwohci_softc *sc = (struct fwohci_softc *)fc;
        struct fwohci_dbch *dbch = &sc->atrs;

        mutex_enter(&dbch->xferq.q_mtx);
        fwohci_start(sc, dbch);
        mutex_exit(&dbch->xferq.q_mtx);
        return;
}

static void
fwohci_txd(struct fwohci_softc *sc, struct fwohci_dbch *dbch)
{
        struct firewire_comm *fc = &sc->fc;
        struct fwohcidb_tr *tr;
        struct fwohcidb *db;
        struct fw_xfer *xfer;
        u_int stat, status;
        int packets = 0, ch, err = 0;

#if DIAGNOSTIC
        if (dbch->off != OHCI_ATQOFF &&
            dbch->off != OHCI_ATSOFF)
                panic("not async tx");
#endif
        if (dbch->off == OHCI_ATQOFF)
                ch = ATRQ_CH;
        else    /* OHCI_ATSOFF */
                ch = ATRS_CH;

        mutex_enter(&dbch->xferq.q_mtx);
        tr = dbch->bottom;
        while (dbch->xferq.queued > 0) {
                fwdma_sync_multiseg(dbch->am, tr->idx, tr->idx,
                    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
                db = LAST_DB(tr);
                status = FWOHCI_DMA_READ(db->db.desc.res) >> OHCI_STATUS_SHIFT;
                if (!(status & OHCI_CNTL_DMA_ACTIVE))
                        if (fc->status != FWBUSINIT)
                                goto out;
                if (tr->xfer->send.pay_len > 0) {
                        bus_dmamap_sync(fc->dmat, tr->dma_map,
                            0, tr->dma_map->dm_mapsize, BUS_DMASYNC_POSTWRITE);
                        bus_dmamap_unload(fc->dmat, tr->dma_map);
                }
#if 1
                if (firewire_debug > 1)
                        dump_db(sc, ch);
#endif
                if (status & OHCI_CNTL_DMA_DEAD) {
                        /* Stop DMA */
                        OWRITE(sc, OHCI_DMACTLCLR(dbch->off),
                            OHCI_CNTL_DMA_RUN);
                        aprint_error_dev(fc->dev, "force reset AT FIFO\n");
                        OWRITE(sc, OHCI_HCCCTLCLR, OHCI_HCC_LINKEN);
                        OWRITE(sc, OHCI_HCCCTL, OHCI_HCC_LPS | OHCI_HCC_LINKEN);
                        OWRITE(sc, OHCI_DMACTLCLR(dbch->off),
                            OHCI_CNTL_DMA_RUN);
                }
                stat = status & FWOHCIEV_MASK;
                switch(stat) {
                case FWOHCIEV_ACKPEND:

                        /* FALLTHROUGH */

                case FWOHCIEV_ACKCOMPL:
                        err = 0;
                        break;

                case FWOHCIEV_ACKBSA:
                case FWOHCIEV_ACKBSB:
                case FWOHCIEV_ACKBSX:
                        aprint_error_dev(fc->dev, "txd err=%2x %s\n", stat,
                            fwohcicode[stat]);
                        err = EBUSY;
                        break;

                case FWOHCIEV_FLUSHED:
                case FWOHCIEV_ACKTARD:
                        aprint_error_dev(fc->dev, "txd err=%2x %s\n", stat,
                            fwohcicode[stat]);
                        err = EAGAIN;
                        break;

                case FWOHCIEV_MISSACK:
                case FWOHCIEV_UNDRRUN:
                case FWOHCIEV_OVRRUN:
                case FWOHCIEV_DESCERR:
                case FWOHCIEV_DTRDERR:
                case FWOHCIEV_TIMEOUT:
                case FWOHCIEV_TCODERR:
                case FWOHCIEV_UNKNOWN:
                case FWOHCIEV_ACKDERR:
                case FWOHCIEV_ACKTERR:
                default:
                        aprint_error_dev(fc->dev, "txd err=%2x %s\n", stat,
                            fwohcicode[stat]);
                        err = EINVAL;
                        break;
                }
                dbch->xferq.queued--;
                dbch->bottom = STAILQ_NEXT(tr, link);
                if (tr->xfer != NULL) {
                        xfer = tr->xfer;
                        tr->xfer = NULL;
                        mutex_exit(&dbch->xferq.q_mtx);
                        if (xfer->flag & FWXF_RCVD) {
#if 0
                                if (firewire_debug)
                                        printf("already rcvd\n");
#endif
                                fw_xfer_done(xfer);
                        } else {
                                microtime(&xfer->tv);
                                xfer->flag = FWXF_SENT;
                                if (err == EBUSY) {
                                        xfer->flag = FWXF_BUSY;
                                        xfer->resp = err;
                                        xfer->recv.pay_len = 0;
                                        fw_xfer_done(xfer);
                                } else if (stat != FWOHCIEV_ACKPEND) {
                                        if (stat != FWOHCIEV_ACKCOMPL)
                                                xfer->flag = FWXF_SENTERR;
                                        xfer->resp = err;
                                        xfer->recv.pay_len = 0;
                                        fw_xfer_done(xfer);
                                }
                        }
                        mutex_enter(&dbch->xferq.q_mtx);
                        /*
                         * The watchdog timer takes care of split
                         * transaction timeout for ACKPEND case.
                         */
                } else
                        aprint_error_dev(fc->dev, "this shouldn't happen\n");
                packets++;
                if (dbch->bottom == dbch->top) {
                        /* we reaches the end of context program */
                        if (firewire_debug && dbch->xferq.queued > 0)
                                printf("queued > 0\n");
                        break;
                }
                tr = dbch->bottom;
        }
out:
        if (dbch->xferq.queued > 0 || packets > 0)
                fwdma_sync_multiseg(dbch->am, tr->idx, tr->idx,
                    BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
        if ((dbch->flags & FWOHCI_DBCH_FULL) && packets > 0) {
                aprint_normal_dev(fc->dev, "make free slot\n");
                dbch->flags &= ~FWOHCI_DBCH_FULL;
                fwohci_start(sc, dbch);
        }
        mutex_exit(&dbch->xferq.q_mtx);
}

static void
fwohci_db_free(struct fwohci_softc *sc, struct fwohci_dbch *dbch)
{
        struct fwohcidb_tr *db_tr, *last;

        if ((dbch->flags & FWOHCI_DBCH_INIT) == 0)
                return;

        for (last = db_tr = STAILQ_FIRST(&dbch->db_trq); db_tr != last;
            db_tr = STAILQ_NEXT(db_tr, link)) {
                bus_dmamap_destroy(sc->fc.dmat, db_tr->dma_map);
                if ((dbch->xferq.flag & FWXFERQ_EXTBUF) == 0 &&
                    db_tr->buf != NULL) {
                        fwdma_free(sc->fc.dmat, db_tr->dma_map, db_tr->buf);
                        db_tr->buf = NULL;
                }
        }
        dbch->ndb = 0;
        db_tr = STAILQ_FIRST(&dbch->db_trq);
        fwdma_free_multiseg(dbch->am);
        free(db_tr, M_FW);
        STAILQ_INIT(&dbch->db_trq);
        dbch->flags &= ~FWOHCI_DBCH_INIT;
        seldestroy(&dbch->xferq.rsel);
}

static void
fwohci_db_init(struct fwohci_softc *sc, struct fwohci_dbch *dbch)
{
        struct firewire_comm *fc = &sc->fc;
        struct fwohcidb_tr *db_tr, *lastq, *tmpq;
        int idb;
        const int db_tr_sz = sizeof(struct fwohcidb_tr) * dbch->ndb;

        if ((dbch->flags & FWOHCI_DBCH_INIT) != 0)
                goto out;

        /* allocate DB entries and attach one to each DMA channels */
        /* DB entry must start at 16 bytes boundary. */
        STAILQ_INIT(&dbch->db_trq);
        db_tr = (struct fwohcidb_tr *)malloc(db_tr_sz, M_FW, M_WAITOK | M_ZERO);
        if (db_tr == NULL) {
                aprint_error_dev(fc->dev, "malloc(1) failed\n");
                return;
        }

#define DB_SIZE(x) (sizeof(struct fwohcidb) * (x)->ndesc)
        dbch->am = fwdma_malloc_multiseg(fc, DB_SIZE(dbch), DB_SIZE(dbch),
#if 0
            dbch->ndb, BUS_DMA_WAITOK);
#else   /* Ooops, debugging now... */
            dbch->ndb, BUS_DMA_WAITOK |
                ((dbch->off == OHCI_ARQOFF || dbch->off == OHCI_ARSOFF) ?
                                                        BUS_DMA_COHERENT : 0));
#endif
        if (dbch->am == NULL) {
                aprint_error_dev(fc->dev, "fwdma_malloc_multiseg failed\n");
                free(db_tr, M_FW);
                return;
        }
        /* Attach DB to DMA ch. */
        for (idb = 0; idb < dbch->ndb; idb++) {
                db_tr->idx = idb;
                db_tr->dbcnt = 0;
                db_tr->db = (struct fwohcidb *)fwdma_v_addr(dbch->am, idb);
                db_tr->bus_addr = fwdma_bus_addr(dbch->am, idb);
                /* create dmamap for buffers */
#define MAX_REQCOUNT    0xffff
                if (bus_dmamap_create(fc->dmat, dbch->xferq.psize,
                    dbch->ndesc > 3 ? dbch->ndesc - 2 : 1, MAX_REQCOUNT, 0,
                    0, &db_tr->dma_map) != 0) {
                        aprint_error_dev(fc->dev, "bus_dmamap_create failed\n");
                        dbch->flags = FWOHCI_DBCH_INIT; /* XXX fake */
                        fwohci_db_free(sc, dbch);
                        return;
                }
                if (dbch->off == OHCI_ARQOFF ||
                    dbch->off == OHCI_ARSOFF) {
                        db_tr->buf = fwdma_malloc(fc->dev, fc->dmat,
                            &db_tr->dma_map, dbch->xferq.psize, 1,
                            BUS_DMA_NOWAIT);
                        if (db_tr->buf == NULL) {
                                aprint_error_dev(fc->dev,
                                    "fwdma_malloc failed\n");
                                dbch->flags = FWOHCI_DBCH_INIT; /* XXX fake */
                                fwohci_db_free(sc, dbch);
                                return;
                        }
                }
                STAILQ_INSERT_TAIL(&dbch->db_trq, db_tr, link);
                if (dbch->xferq.flag & FWXFERQ_EXTBUF) {
                        struct fw_bulkxfer *bulkxfer =
                            &dbch->xferq.bulkxfer[idb / dbch->xferq.bnpacket];

                        if (idb % dbch->xferq.bnpacket == 0)
                                bulkxfer->start = (void *)db_tr;
                        if ((idb + 1) % dbch->xferq.bnpacket == 0)
                                bulkxfer->end = (void *)db_tr;
                }
                db_tr++;
        }
        lastq = NULL;
        STAILQ_FOREACH(tmpq, &dbch->db_trq, link)
                lastq = tmpq;
        lastq->link.stqe_next = STAILQ_FIRST(&dbch->db_trq);
out:
        dbch->xferq.queued = 0;
        dbch->pdb_tr = NULL;
        dbch->top = STAILQ_FIRST(&dbch->db_trq);
        dbch->bottom = dbch->top;
        dbch->flags = FWOHCI_DBCH_INIT;
        selinit(&dbch->xferq.rsel);
}

static int
fwohci_tx_enable(struct fwohci_softc *sc, struct fwohci_dbch *dbch)
{
        int err = 0;
        int idb, z, i, dmach = 0, ldesc;
        struct fwohcidb_tr *db_tr;
        struct fwohcidb *db;

        if (!(dbch->xferq.flag & FWXFERQ_EXTBUF)) {
                err = EINVAL;
                return err;
        }
        z = dbch->ndesc;
        for (dmach = 0; dmach < sc->fc.nisodma; dmach++)
                if (dbch->off == sc->it[dmach].off)
                        break;
        if (dmach == sc->fc.nisodma) {
                err = EINVAL;
                return err;
        }
        if (dbch->xferq.flag & FWXFERQ_RUNNING)
                return err;
        dbch->xferq.flag |= FWXFERQ_RUNNING;
        for (i = 0, dbch->bottom = dbch->top; i < dbch->ndb - 1; i++)
                dbch->bottom = STAILQ_NEXT(dbch->bottom, link);
        db_tr = dbch->top;
        for (idb = 0; idb < dbch->ndb; idb++) {
                fwohci_add_tx_buf(dbch, db_tr, idb);
                if (STAILQ_NEXT(db_tr, link) == NULL)
                        break;
                db = db_tr->db;
                ldesc = db_tr->dbcnt - 1;
                FWOHCI_DMA_WRITE(db[0].db.desc.depend,
                    STAILQ_NEXT(db_tr, link)->bus_addr | z);
                db[ldesc].db.desc.depend = db[0].db.desc.depend;
                if (dbch->xferq.flag & FWXFERQ_EXTBUF) {
                        if (((idb + 1) % dbch->xferq.bnpacket) == 0) {
                                FWOHCI_DMA_SET(db[ldesc].db.desc.cmd,
                                    OHCI_INTERRUPT_ALWAYS);
                                /* OHCI 1.1 and above */
                                FWOHCI_DMA_SET(db[0].db.desc.cmd,
                                    OHCI_INTERRUPT_ALWAYS);
                        }
                }
                db_tr = STAILQ_NEXT(db_tr, link);
        }
        FWOHCI_DMA_CLEAR(
            dbch->bottom->db[dbch->bottom->dbcnt - 1].db.desc.depend, 0xf);
        return err;
}

static int
fwohci_rx_enable(struct fwohci_softc *sc, struct fwohci_dbch *dbch)
{
        struct fwohcidb_tr *db_tr;
        struct fwohcidb *db;
        int idb, z, i, ldesc, err = 0;

        z = dbch->ndesc;
        if (dbch->xferq.flag & FWXFERQ_STREAM) {
                if (dbch->xferq.flag & FWXFERQ_RUNNING)
                        return err;
        } else
                if (dbch->xferq.flag & FWXFERQ_RUNNING) {
                        err = EBUSY;
                        return err;
                }
        dbch->xferq.flag |= FWXFERQ_RUNNING;
        dbch->top = STAILQ_FIRST(&dbch->db_trq);
        for (i = 0, dbch->bottom = dbch->top; i < dbch->ndb - 1; i++)
                dbch->bottom = STAILQ_NEXT(dbch->bottom, link);
        db_tr = dbch->top;
        if (db_tr->dbcnt != 0)
                goto run;
        for (idb = 0; idb < dbch->ndb; idb++) {
                if (dbch->off == OHCI_ARQOFF ||
                    dbch->off == OHCI_ARSOFF)
                        bus_dmamap_sync(sc->fc.dmat, db_tr->dma_map,
                            0, db_tr->dma_map->dm_mapsize, BUS_DMASYNC_PREREAD);
                fwohci_add_rx_buf(dbch, db_tr, idb, &sc->dummy_dma);
                if (STAILQ_NEXT(db_tr, link) == NULL)
                        break;
                db = db_tr->db;
                ldesc = db_tr->dbcnt - 1;
                FWOHCI_DMA_WRITE(db[ldesc].db.desc.depend,
                    STAILQ_NEXT(db_tr, link)->bus_addr | z);
                if (dbch->xferq.flag & FWXFERQ_EXTBUF) {
                        if (((idb + 1) % dbch->xferq.bnpacket) == 0) {
                                FWOHCI_DMA_SET(db[ldesc].db.desc.cmd,
                                    OHCI_INTERRUPT_ALWAYS);
                                FWOHCI_DMA_CLEAR(db[ldesc].db.desc.depend, 0xf);
                        }
                }
                db_tr = STAILQ_NEXT(db_tr, link);
        }
        FWOHCI_DMA_CLEAR(dbch->bottom->db[db_tr->dbcnt - 1].db.desc.depend,
            0xf);
        dbch->buf_offset = 0;
run:
        fwdma_sync_multiseg_all(dbch->am,
            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
        if (!(dbch->xferq.flag & FWXFERQ_STREAM)) {
                OWRITE(sc, OHCI_DMACMD(dbch->off), dbch->top->bus_addr | z);
                OWRITE(sc, OHCI_DMACTL(dbch->off), OHCI_CNTL_DMA_RUN);
        }
        return err;
}

static int
fwohci_next_cycle(struct fwohci_softc *sc, int cycle_now)
{
        int sec, cycle, cycle_match;

        cycle = cycle_now & 0x1fff;
        sec = cycle_now >> 13;
#define CYCLE_MOD       0x10
#if 1
#define CYCLE_DELAY     8       /* min delay to start DMA */
#else
#define CYCLE_DELAY     7000    /* min delay to start DMA */
#endif
        cycle = cycle + CYCLE_DELAY;
        if (cycle >= 8000) {
                sec++;
                cycle -= 8000;
        }
        cycle = roundup2(cycle, CYCLE_MOD);
        if (cycle >= 8000) {
                sec++;
                if (cycle == 8000)
                        cycle = 0;
                else
                        cycle = CYCLE_MOD;
        }
        cycle_match = ((sec << 13) | cycle) & 0x7ffff;

        return cycle_match;
}

#ifdef OHCI_DEBUG
static void
fwohci_dump_intr(struct fwohci_softc *sc, uint32_t stat)
{

        if (stat & OREAD(sc, FWOHCI_INTMASK))
                print("%s: INTERRUPT"
                    " < %s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s>"
                    " 0x%08x, 0x%08x\n",
                    device_xname(fc->dev),
                    stat & OHCI_INT_EN ? "DMA_EN ":"",
                    stat & OHCI_INT_PHY_REG ? "PHY_REG ":"",
                    stat & OHCI_INT_CYC_LONG ? "CYC_LONG ":"",
                    stat & OHCI_INT_ERR ? "INT_ERR ":"",
                    stat & OHCI_INT_CYC_ERR ? "CYC_ERR ":"",
                    stat & OHCI_INT_CYC_LOST ? "CYC_LOST ":"",
                    stat & OHCI_INT_CYC_64SECOND ? "CYC_64SECOND ":"",
                    stat & OHCI_INT_CYC_START ? "CYC_START ":"",
                    stat & OHCI_INT_PHY_INT ? "PHY_INT ":"",
                    stat & OHCI_INT_PHY_BUS_R ? "BUS_RESET ":"",
                    stat & OHCI_INT_PHY_SID ? "SID ":"",
                    stat & OHCI_INT_LR_ERR ? "DMA_LR_ERR ":"",
                    stat & OHCI_INT_PW_ERR ? "DMA_PW_ERR ":"",
                    stat & OHCI_INT_DMA_IR ? "DMA_IR ":"",
                    stat & OHCI_INT_DMA_IT ? "DMA_IT " :"",
                    stat & OHCI_INT_DMA_PRRS ? "DMA_PRRS " :"",
                    stat & OHCI_INT_DMA_PRRQ ? "DMA_PRRQ " :"",
                    stat & OHCI_INT_DMA_ARRS ? "DMA_ARRS " :"",
                    stat & OHCI_INT_DMA_ARRQ ? "DMA_ARRQ " :"",
                    stat & OHCI_INT_DMA_ATRS ? "DMA_ATRS " :"",
                    stat & OHCI_INT_DMA_ATRQ ? "DMA_ATRQ " :"",
                    stat, OREAD(sc, FWOHCI_INTMASK)
                );
}
#endif

static void
fwohci_intr_core(struct fwohci_softc *sc, uint32_t stat)
{
        struct firewire_comm *fc = &sc->fc;
        uint32_t node_id, plen;

        if ((stat & OHCI_INT_PHY_BUS_R) && (fc->status != FWBUSRESET)) {
                fc->status = FWBUSRESET;
                /* Disable bus reset interrupt until sid recv. */
                OWRITE(sc, FWOHCI_INTMASKCLR, OHCI_INT_PHY_BUS_R);

                aprint_normal_dev(fc->dev, "BUS reset\n");
                OWRITE(sc, FWOHCI_INTMASKCLR, OHCI_INT_CYC_LOST);
                OWRITE(sc, OHCI_LNKCTLCLR, OHCI_CNTL_CYCSRC);

                OWRITE(sc, OHCI_ATQCTLCLR, OHCI_CNTL_DMA_RUN);
                sc->atrq.xferq.flag &= ~FWXFERQ_RUNNING;
                OWRITE(sc, OHCI_ATSCTLCLR, OHCI_CNTL_DMA_RUN);
                sc->atrs.xferq.flag &= ~FWXFERQ_RUNNING;

                fw_busreset(&sc->fc, FWBUSRESET);
                OWRITE(sc, OHCI_CROMHDR, ntohl(sc->fc.config_rom[0]));
                OWRITE(sc, OHCI_BUS_OPT, ntohl(sc->fc.config_rom[2]));
        }
        if (stat & OHCI_INT_PHY_SID) {
                /* Enable bus reset interrupt */
                OWRITE(sc, FWOHCI_INTSTATCLR, OHCI_INT_PHY_BUS_R);
                OWRITE(sc, FWOHCI_INTMASK, OHCI_INT_PHY_BUS_R);

                /* Allow async. request to us */
                OWRITE(sc, OHCI_AREQHI, 1U << 31);
                if (firewire_phydma_enable) {
                        /* allow from all nodes */
                        OWRITE(sc, OHCI_PREQHI, 0x7fffffff);
                        OWRITE(sc, OHCI_PREQLO, 0xffffffff);
                        /* 0 to 4GB region */
                        OWRITE(sc, OHCI_PREQUPPER, 0x10000);
                }
                /* Set ATRetries register */
                OWRITE(sc, OHCI_ATRETRY, 1<<(13+16) | 0xfff);

                /*
                 * Checking whether the node is root or not. If root, turn on
                 * cycle master.
                 */
                node_id = OREAD(sc, FWOHCI_NODEID);
                plen = OREAD(sc, OHCI_SID_CNT);

                fc->nodeid = node_id & 0x3f;
                aprint_normal_dev(fc->dev, "node_id=0x%08x, gen=%d, ",
                    node_id, (plen >> 16) & 0xff);
                if (!(node_id & OHCI_NODE_VALID)) {
                        aprint_error_dev(fc->dev, "Bus reset failure\n");
                        goto sidout;
                }

                /* cycle timer */
                sc->cycle_lost = 0;
                OWRITE(sc, FWOHCI_INTMASK, OHCI_INT_CYC_LOST);
                if ((node_id & OHCI_NODE_ROOT) && !nocyclemaster) {
                        aprint_normal("CYCLEMASTER mode\n");
                        OWRITE(sc, OHCI_LNKCTL,
                            OHCI_CNTL_CYCMTR | OHCI_CNTL_CYCTIMER);
                } else {
                        aprint_normal("non CYCLEMASTER mode\n");
                        OWRITE(sc, OHCI_LNKCTLCLR, OHCI_CNTL_CYCMTR);
                        OWRITE(sc, OHCI_LNKCTL, OHCI_CNTL_CYCTIMER);
                }

                fc->status = FWBUSINIT;

                fwohci_task_sid(sc);
        }
sidout:
        if ((stat & ~(OHCI_INT_PHY_BUS_R | OHCI_INT_PHY_SID)))
                fwohci_task_dma(sc);
}

static void
fwohci_intr_dma(struct fwohci_softc *sc, uint32_t stat)
{
        struct firewire_comm *fc = &sc->fc;
        uint32_t irstat, itstat;
        u_int i;

        if (stat & OHCI_INT_DMA_IR) {
                irstat = atomic_swap_32(&sc->irstat, 0);
                for (i = 0; i < fc->nisodma; i++)
                        if ((irstat & (1 << i)) != 0) {
                                struct fwohci_dbch *dbch = &sc->ir[i];

                                if ((dbch->xferq.flag & FWXFERQ_OPEN) == 0) {
                                        aprint_error_dev(fc->dev,
                                            "dma(%d) not active\n", i);
                                        continue;
                                }
                                fwohci_rbuf_update(sc, i);
                        }
        }
        if (stat & OHCI_INT_DMA_IT) {
                itstat = atomic_swap_32(&sc->itstat, 0);
                for (i = 0; i < fc->nisodma; i++)
                        if ((itstat & (1 << i)) != 0)
                                fwohci_tbuf_update(sc, i);
        }
        if (stat & OHCI_INT_DMA_PRRS) {
#if 0
                dump_dma(sc, ARRS_CH);
                dump_db(sc, ARRS_CH);
#endif
                fwohci_arcv(sc, &sc->arrs);
        }
        if (stat & OHCI_INT_DMA_PRRQ) {
#if 0
                dump_dma(sc, ARRQ_CH);
                dump_db(sc, ARRQ_CH);
#endif
                fwohci_arcv(sc, &sc->arrq);
        }
        if (stat & OHCI_INT_CYC_LOST) {
                if (sc->cycle_lost >= 0)
                        sc->cycle_lost++;
                if (sc->cycle_lost > 10) {
                        sc->cycle_lost = -1;
#if 0
                        OWRITE(sc, OHCI_LNKCTLCLR, OHCI_CNTL_CYCTIMER);
#endif
                        OWRITE(sc, FWOHCI_INTMASKCLR, OHCI_INT_CYC_LOST);
                        aprint_error_dev(fc->dev, "too many cycle lost, "
                            "no cycle master present?\n");
                }
        }
        if (stat & OHCI_INT_DMA_ATRQ)
                fwohci_txd(sc, &(sc->atrq));
        if (stat & OHCI_INT_DMA_ATRS)
                fwohci_txd(sc, &(sc->atrs));
        if (stat & OHCI_INT_PW_ERR)
                aprint_error_dev(fc->dev, "posted write error\n");
        if (stat & OHCI_INT_ERR)
                aprint_error_dev(fc->dev, "unrecoverable error\n");
        if (stat & OHCI_INT_PHY_INT)
                aprint_normal_dev(fc->dev, "phy int\n");

        return;
}

static void
fwohci_task_sid(struct fwohci_softc *sc)
{
        struct firewire_comm *fc = &sc->fc;
        uint32_t *buf;
        int i, plen;

        plen = OREAD(sc, OHCI_SID_CNT);

        if (plen & OHCI_SID_ERR) {
                aprint_error_dev(fc->dev, "SID Error\n");
                return;
        }
        plen &= OHCI_SID_CNT_MASK;
        if (plen < 4 || plen > OHCI_SIDSIZE) {
                aprint_error_dev(fc->dev, "invalid SID len = %d\n", plen);
                return;
        }
        plen -= 4; /* chop control info */
        buf = (uint32_t *)malloc(OHCI_SIDSIZE, M_FW, M_NOWAIT);
        if (buf == NULL) {
                aprint_error_dev(fc->dev, "malloc failed\n");
                return;
        }
        for (i = 0; i < plen / 4; i++)
                buf[i] = FWOHCI_DMA_READ(sc->sid_buf[i + 1]);
#if 1 /* XXX needed?? */
        /* pending all pre-bus_reset packets */
        fwohci_txd(sc, &sc->atrq);
        fwohci_txd(sc, &sc->atrs);
        fwohci_arcv(sc, &sc->arrs);
        fwohci_arcv(sc, &sc->arrq);
        fw_drain_txq(fc);
#endif
        fw_sidrcv(fc, buf, plen);
        free(buf, M_FW);
}

static void
fwohci_task_dma(struct fwohci_softc *sc)
{
        uint32_t stat;

again:
        stat = atomic_swap_32(&sc->intstat, 0);
        if (stat)
                fwohci_intr_dma(sc, stat);
        else
                return;
        goto again;
}

static void
fwohci_tbuf_update(struct fwohci_softc *sc, int dmach)
{
        struct firewire_comm *fc = &sc->fc;
        struct fwohcidb *db;
        struct fw_bulkxfer *chunk;
        struct fw_xferq *it;
        uint32_t stat;
#if 0
        uint32_t count;
#endif
        int w = 0, ldesc;

        it = fc->it[dmach];
        ldesc = sc->it[dmach].ndesc - 1;
        mutex_enter(&fc->fc_mtx);
        fwdma_sync_multiseg_all(sc->it[dmach].am, BUS_DMASYNC_POSTREAD);
        if (firewire_debug)
                dump_db(sc, ITX_CH + dmach);
        while ((chunk = STAILQ_FIRST(&it->stdma)) != NULL) {
                db = ((struct fwohcidb_tr *)(chunk->end))->db;
                stat =
                    FWOHCI_DMA_READ(db[ldesc].db.desc.res) >> OHCI_STATUS_SHIFT;
                db = ((struct fwohcidb_tr *)(chunk->start))->db;
                /* timestamp */
#if 0
                count =
                    FWOHCI_DMA_READ(db[ldesc].db.desc.res) & OHCI_COUNT_MASK;
#else
                (void)FWOHCI_DMA_READ(db[ldesc].db.desc.res);
#endif
                if (stat == 0)
                        break;
                STAILQ_REMOVE_HEAD(&it->stdma, link);
                switch (stat & FWOHCIEV_MASK) {
                case FWOHCIEV_ACKCOMPL:
#if 0
                        printf("0x%08x\n", count);
#endif
                        break;
                default:
                        aprint_error_dev(fc->dev,
                            "Isochronous transmit err %02x(%s)\n",
                            stat, fwohcicode[stat & 0x1f]);
                }
                STAILQ_INSERT_TAIL(&it->stfree, chunk, link);
                w++;
        }
        if (w)
                cv_broadcast(&it->cv);
        mutex_exit(&fc->fc_mtx);
}

static void
fwohci_rbuf_update(struct fwohci_softc *sc, int dmach)
{
        struct firewire_comm *fc = &sc->fc;
        struct fwohcidb_tr *db_tr;
        struct fw_bulkxfer *chunk;
        struct fw_xferq *ir;
        uint32_t stat;
        int w = 0, ldesc;

        ir = fc->ir[dmach];
        ldesc = sc->ir[dmach].ndesc - 1;

#if 0
        dump_db(sc, dmach);
#endif
        if ((ir->flag & FWXFERQ_HANDLER) == 0)
                mutex_enter(&fc->fc_mtx);
        fwdma_sync_multiseg_all(sc->ir[dmach].am, BUS_DMASYNC_POSTREAD);
        while ((chunk = STAILQ_FIRST(&ir->stdma)) != NULL) {
                db_tr = (struct fwohcidb_tr *)chunk->end;
                stat = FWOHCI_DMA_READ(db_tr->db[ldesc].db.desc.res) >>
                    OHCI_STATUS_SHIFT;
                if (stat == 0)
                        break;

                if (chunk->mbuf != NULL) {
                        bus_dmamap_sync(fc->dmat, db_tr->dma_map, 0,
                            db_tr->dma_map->dm_mapsize, BUS_DMASYNC_POSTREAD);
                        bus_dmamap_unload(fc->dmat, db_tr->dma_map);
                } else if (ir->buf != NULL)
                        fwdma_sync_multiseg(ir->buf, chunk->poffset,
                            ir->bnpacket, BUS_DMASYNC_POSTREAD);
                else
                        /* XXX */
                        aprint_error_dev(fc->dev,
                            "fwohci_rbuf_update: this shouldn't happen\n");

                STAILQ_REMOVE_HEAD(&ir->stdma, link);
                STAILQ_INSERT_TAIL(&ir->stvalid, chunk, link);
                switch (stat & FWOHCIEV_MASK) {
                case FWOHCIEV_ACKCOMPL:
                        chunk->resp = 0;
                        break;
                default:
                        chunk->resp = EINVAL;
                        aprint_error_dev(fc->dev,
                            "Isochronous receive err %02x(%s)\n",
                            stat, fwohcicode[stat & 0x1f]);
                }
                w++;
        }
        if ((ir->flag & FWXFERQ_HANDLER) == 0) {
                if (w)
                        cv_broadcast(&ir->cv);
                mutex_exit(&fc->fc_mtx);
        }
        if (w == 0)
                return;
        if (ir->flag & FWXFERQ_HANDLER)
                ir->hand(ir);
}

static void
dump_dma(struct fwohci_softc *sc, uint32_t ch)
{
        struct fwohci_dbch *dbch;
        uint32_t cntl, stat, cmd, match;

        if (ch == ATRQ_CH)
                dbch = &sc->atrq;
        else if (ch == ATRS_CH)
                dbch = &sc->atrs;
        else if (ch == ARRQ_CH)
                dbch = &sc->arrq;
        else if (ch == ARRS_CH)
                dbch = &sc->arrs;
        else if (ch < IRX_CH)
                dbch = &sc->it[ch - ITX_CH];
        else
                dbch = &sc->ir[ch - IRX_CH];
        cntl = stat = OREAD(sc, dbch->off);
        cmd = OREAD(sc, dbch->off + 0xc);
        match = OREAD(sc, dbch->off + 0x10);

        aprint_normal_dev(sc->fc.dev,
            "ch %1x cntl:0x%08x cmd:0x%08x match:0x%08x\n",
            ch,
            cntl,
            cmd,
            match);
        stat &= 0xffff;
        if (stat)
                aprint_normal_dev(sc->fc.dev, "dma %d ch:%s%s%s%s%s%s %s(%x)\n",
                    ch,
                    stat & OHCI_CNTL_DMA_RUN ? "RUN," : "",
                    stat & OHCI_CNTL_DMA_WAKE ? "WAKE," : "",
                    stat & OHCI_CNTL_DMA_DEAD ? "DEAD," : "",
                    stat & OHCI_CNTL_DMA_ACTIVE ? "ACTIVE," : "",
                    stat & OHCI_CNTL_DMA_BT ? "BRANCH," : "",
                    stat & OHCI_CNTL_DMA_BAD ? "BADDMA," : "",
                    fwohcicode[stat & 0x1f],
                    stat & 0x1f
                );
        else
                aprint_normal_dev(sc->fc.dev, "dma %d ch: Nostat\n", ch);
}

static void
dump_db(struct fwohci_softc *sc, uint32_t ch)
{
        struct fwohci_dbch *dbch;
        struct fwohcidb_tr *cp = NULL, *pp;
        struct fwohcidb *curr = NULL;
#if 0
        struct fwohcidb_tr *np = NULL;
        struct fwohcidb *prev, *next = NULL;
#endif
        int idb, jdb;
        uint32_t cmd;

        if (ch == ATRQ_CH)
                dbch = &sc->atrq;
        else if (ch == ATRS_CH)
                dbch = &sc->atrs;
        else if (ch == ARRQ_CH)
                dbch = &sc->arrq;
        else if (ch == ARRS_CH)
                dbch = &sc->arrs;
        else if (ch < IRX_CH)
                dbch = &sc->it[ch - ITX_CH];
        else
                dbch = &sc->ir[ch - IRX_CH];
        cmd = OREAD(sc, dbch->off + 0xc);

        if (dbch->ndb == 0) {
                aprint_error_dev(sc->fc.dev, "No DB is attached ch=%d\n", ch);
                return;
        }
        pp = dbch->top;
#if 0
        prev = pp->db;
#endif
        for (idb = 0; idb < dbch->ndb; idb++) {
                cp = STAILQ_NEXT(pp, link);
                if (cp == NULL) {
                        curr = NULL;
                        goto outdb;
                }
#if 0
                np = STAILQ_NEXT(cp, link);
#endif
                for (jdb = 0; jdb < dbch->ndesc; jdb++)
                        if ((cmd & 0xfffffff0) == cp->bus_addr) {
                                curr = cp->db;
#if 0
                                if (np != NULL)
                                        next = np->db;
                                else
                                        next = NULL;
#endif
                                goto outdb;
                        }
                pp = STAILQ_NEXT(pp, link);
                if (pp == NULL) {
                        curr = NULL;
                        goto outdb;
                }
#if 0
                prev = pp->db;
#endif
        }
outdb:
        if (curr != NULL) {
#if 0
                aprint_normal("Prev DB %d\n", ch);
                print_db(pp, prev, ch, dbch->ndesc);
#endif
                aprint_normal("Current DB %d\n", ch);
                print_db(cp, curr, ch, dbch->ndesc);
#if 0
                aprint_normal("Next DB %d\n", ch);
                print_db(np, next, ch, dbch->ndesc);
#endif
        } else
                aprint_error("dbdump err ch = %d cmd = 0x%08x\n", ch, cmd);
        return;
}

static void
print_db(struct fwohcidb_tr *db_tr, struct fwohcidb *db, uint32_t ch,
         uint32_t hogemax)
{
        fwohcireg_t stat;
        int i, key;
        uint32_t cmd, res;

        if (db == NULL) {
                aprint_error("No Descriptor is found\n");
                return;
        }

        aprint_normal("ch = %d\n%8s %s %s %s %s %4s %8s %8s %4s:%4s\n",
            ch,
            "Current",
            "OP  ",
            "KEY",
            "INT",
            "BR ",
            "len",
            "Addr",
            "Depend",
            "Stat",
            "Cnt");
        for (i = 0; i <= hogemax; i++) {
                cmd = FWOHCI_DMA_READ(db[i].db.desc.cmd);
                res = FWOHCI_DMA_READ(db[i].db.desc.res);
                key = cmd & OHCI_KEY_MASK;
                stat = res >> OHCI_STATUS_SHIFT;
                aprint_normal("%08jx %s %s %s %s %5d %08x %08x %04x:%04x",
                    (uintmax_t)db_tr->bus_addr,
                    dbcode[(cmd >> 28) & 0xf],
                    dbkey[(cmd >> 24) & 0x7],
                    dbcond[(cmd >> 20) & 0x3],
                    dbcond[(cmd >> 18) & 0x3],
                    cmd & OHCI_COUNT_MASK,
                    FWOHCI_DMA_READ(db[i].db.desc.addr),
                    FWOHCI_DMA_READ(db[i].db.desc.depend),
                    stat,
                    res & OHCI_COUNT_MASK);
                if (stat & 0xff00)
                        aprint_normal(" %s%s%s%s%s%s %s(%x)\n",
                            stat & OHCI_CNTL_DMA_RUN ? "RUN," : "",
                            stat & OHCI_CNTL_DMA_WAKE ? "WAKE," : "",
                            stat & OHCI_CNTL_DMA_DEAD ? "DEAD," : "",
                            stat & OHCI_CNTL_DMA_ACTIVE ? "ACTIVE," : "",
                            stat & OHCI_CNTL_DMA_BT ? "BRANCH," : "",
                            stat & OHCI_CNTL_DMA_BAD ? "BADDMA," : "",
                            fwohcicode[stat & 0x1f],
                            stat & 0x1f
                        );
                else
                        aprint_normal(" Nostat\n");
                if (key == OHCI_KEY_ST2)
                        aprint_normal("0x%08x 0x%08x 0x%08x 0x%08x\n",
                            FWOHCI_DMA_READ(db[i+1].db.immed[0]),
                            FWOHCI_DMA_READ(db[i+1].db.immed[1]),
                            FWOHCI_DMA_READ(db[i+1].db.immed[2]),
                            FWOHCI_DMA_READ(db[i+1].db.immed[3]));
                if (key == OHCI_KEY_DEVICE)
                        return;
                if ((cmd & OHCI_BRANCH_MASK) == OHCI_BRANCH_ALWAYS)
                        return;
                if ((cmd & OHCI_CMD_MASK) == OHCI_OUTPUT_LAST)
                        return;
                if ((cmd & OHCI_CMD_MASK) == OHCI_INPUT_LAST)
                        return;
                if (key == OHCI_KEY_ST2)
                        i++;
        }
        return;
}

static void
fwohci_txbufdb(struct fwohci_softc *sc, int dmach, struct fw_bulkxfer *bulkxfer)
{
        struct fwohcidb_tr *db_tr /*, *fdb_tr */;
        struct fwohci_dbch *dbch;
        struct fwohcidb *db;
        struct fw_pkt *fp;
        struct fwohci_txpkthdr *ohcifp;
        unsigned short chtag;
        int idb;

        KASSERT(mutex_owned(&sc->fc.fc_mtx));

        dbch = &sc->it[dmach];
        chtag = sc->it[dmach].xferq.flag & 0xff;

        db_tr = (struct fwohcidb_tr *)(bulkxfer->start);
/*
        fdb_tr = (struct fwohcidb_tr *)(bulkxfer->end);
aprint_normal(sc->fc.dev, "DB %08x %08x %08x\n", bulkxfer, db_tr->bus_addr, fdb_tr->bus_addr);
*/
        for (idb = 0; idb < dbch->xferq.bnpacket; idb++) {
                db = db_tr->db;
                fp = (struct fw_pkt *)db_tr->buf;
                ohcifp = (struct fwohci_txpkthdr *) db[1].db.immed;
                ohcifp->mode.ld[0] = fp->mode.ld[0];
                ohcifp->mode.common.spd = 0 & 0x7;
                ohcifp->mode.stream.len = fp->mode.stream.len;
                ohcifp->mode.stream.chtag = chtag;
                ohcifp->mode.stream.tcode = 0xa;
#if BYTE_ORDER == BIG_ENDIAN
                FWOHCI_DMA_WRITE(db[1].db.immed[0], db[1].db.immed[0]);
                FWOHCI_DMA_WRITE(db[1].db.immed[1], db[1].db.immed[1]);
#endif

                FWOHCI_DMA_CLEAR(db[2].db.desc.cmd, OHCI_COUNT_MASK);
                FWOHCI_DMA_SET(db[2].db.desc.cmd, fp->mode.stream.len);
                FWOHCI_DMA_WRITE(db[2].db.desc.res, 0);
#if 0 /* if bulkxfer->npackets changes */
                db[2].db.desc.cmd =
                    OHCI_OUTPUT_LAST | OHCI_UPDATE | OHCI_BRANCH_ALWAYS;
                db[0].db.desc.depend = db[dbch->ndesc - 1].db.desc.depend =
                    STAILQ_NEXT(db_tr, link)->bus_addr | dbch->ndesc;
#else
                FWOHCI_DMA_SET(db[0].db.desc.depend, dbch->ndesc);
                FWOHCI_DMA_SET(db[dbch->ndesc - 1].db.desc.depend, dbch->ndesc);
#endif
                bulkxfer->end = (void *)db_tr;
                db_tr = STAILQ_NEXT(db_tr, link);
        }
        db = ((struct fwohcidb_tr *)bulkxfer->end)->db;
        FWOHCI_DMA_CLEAR(db[0].db.desc.depend, 0xf);
        FWOHCI_DMA_CLEAR(db[dbch->ndesc - 1].db.desc.depend, 0xf);
#if 0 /* if bulkxfer->npackets changes */
        db[dbch->ndesc - 1].db.desc.control |= OHCI_INTERRUPT_ALWAYS;
        /* OHCI 1.1 and above */
        db[0].db.desc.control |= OHCI_INTERRUPT_ALWAYS;
#endif
/*
        db_tr = (struct fwohcidb_tr *)bulkxfer->start;
        fdb_tr = (struct fwohcidb_tr *)bulkxfer->end;
aprint_normal(sc->fc.dev, "DB %08x %3d %08x %08x\n", bulkxfer, bulkxfer->npacket, db_tr->bus_addr, fdb_tr->bus_addr);
*/
        return;
}

static int
fwohci_add_tx_buf(struct fwohci_dbch *dbch, struct fwohcidb_tr *db_tr,
                  int poffset)
{
        struct fwohcidb *db = db_tr->db;
        struct fw_xferq *it;
        int err = 0;

        it = &dbch->xferq;
        if (it->buf == 0) {
                err = EINVAL;
                return err;
        }
        db_tr->buf = fwdma_v_addr(it->buf, poffset);
        db_tr->dbcnt = 3;

        FWOHCI_DMA_WRITE(db[0].db.desc.cmd,
            OHCI_OUTPUT_MORE | OHCI_KEY_ST2 | 8);
        FWOHCI_DMA_WRITE(db[0].db.desc.addr, 0);
        memset((void *)db[1].db.immed, 0, sizeof(db[1].db.immed));
        FWOHCI_DMA_WRITE(db[2].db.desc.addr,
            fwdma_bus_addr(it->buf, poffset) + sizeof(uint32_t));

        FWOHCI_DMA_WRITE(db[2].db.desc.cmd,
            OHCI_OUTPUT_LAST | OHCI_UPDATE | OHCI_BRANCH_ALWAYS);
#if 1
        FWOHCI_DMA_WRITE(db[0].db.desc.res, 0);
        FWOHCI_DMA_WRITE(db[2].db.desc.res, 0);
#endif
        return 0;
}

int
fwohci_add_rx_buf(struct fwohci_dbch *dbch, struct fwohcidb_tr *db_tr,
                  int poffset, struct fwdma_alloc *dummy_dma)
{
        struct fwohcidb *db = db_tr->db;
        struct fw_xferq *rq;
        int i, ldesc;
        bus_addr_t dbuf[2];
        int dsiz[2];

        rq = &dbch->xferq;
        if (rq->buf == NULL && (dbch->xferq.flag & FWXFERQ_EXTBUF) == 0) {
                /* async */
                db_tr->dbcnt = 1;
                dsiz[0] = rq->psize;
                dbuf[0] = db_tr->dma_map->dm_segs[0].ds_addr;
        } else {
                /* isoc */
                db_tr->dbcnt = 0;
                dsiz[db_tr->dbcnt] = sizeof(uint32_t);
                dbuf[db_tr->dbcnt++] = dummy_dma->bus_addr;
                dsiz[db_tr->dbcnt] = rq->psize;
                if (rq->buf != NULL) {
                        db_tr->buf = fwdma_v_addr(rq->buf, poffset);
                        dbuf[db_tr->dbcnt] = fwdma_bus_addr(rq->buf, poffset);
                }
                db_tr->dbcnt++;
        }
        for (i = 0; i < db_tr->dbcnt; i++) {
                FWOHCI_DMA_WRITE(db[i].db.desc.addr, dbuf[i]);
                FWOHCI_DMA_WRITE(db[i].db.desc.cmd, OHCI_INPUT_MORE | dsiz[i]);
                if (rq->flag & FWXFERQ_STREAM)
                        FWOHCI_DMA_SET(db[i].db.desc.cmd, OHCI_UPDATE);
                FWOHCI_DMA_WRITE(db[i].db.desc.res, dsiz[i]);
        }
        ldesc = db_tr->dbcnt - 1;
        if (rq->flag & FWXFERQ_STREAM)
                FWOHCI_DMA_SET(db[ldesc].db.desc.cmd, OHCI_INPUT_LAST);
        FWOHCI_DMA_SET(db[ldesc].db.desc.cmd, OHCI_BRANCH_ALWAYS);
        return 0;
}


static int
fwohci_arcv_swap(struct fw_pkt *fp, int len)
{
        struct fw_pkt *fp0;
        union {
                uint32_t ld0;
                struct fw_pkt pkt;
        } pktu;
        int hlen;
#if BYTE_ORDER == BIG_ENDIAN
        int slen, i;
#endif

        pktu.ld0 = FWOHCI_DMA_READ(fp->mode.ld[0]);
#if 0
        printf("ld0: x%08x\n", pktu.ld0);
#endif
        fp0 = (struct fw_pkt *)&pktu;
        /* determine length to swap */
        switch (fp0->mode.common.tcode) {
        case FWTCODE_WRES:
        case FWTCODE_RREQQ:
        case FWTCODE_WREQQ:
        case FWTCODE_RRESQ:
        case FWOHCITCODE_PHY:
#if BYTE_ORDER == BIG_ENDIAN
                slen = 12;
#endif
                break;

        case FWTCODE_RREQB:
        case FWTCODE_WREQB:
        case FWTCODE_LREQ:
        case FWTCODE_RRESB:
        case FWTCODE_LRES:
#if BYTE_ORDER == BIG_ENDIAN
                slen = 16;
#endif
                break;

        default:
                aprint_error("Unknown tcode %d\n", fp0->mode.common.tcode);
                return 0;
        }
        hlen = tinfo[fp0->mode.common.tcode].hdr_len;
        if (hlen > len) {
                if (firewire_debug)
                        printf("split header\n");
                return len - hlen;
        }
#if BYTE_ORDER == BIG_ENDIAN
        for (i = 0; i < slen / 4; i++)
                fp->mode.ld[i] = FWOHCI_DMA_READ(fp->mode.ld[i]);
#endif
        return hlen;
}

static int
fwohci_get_plen(struct fwohci_softc *sc, struct fwohci_dbch *dbch,
                struct fw_pkt *fp)
{
        const struct tcode_info *info;
        int r;

        info = &tinfo[fp->mode.common.tcode];
        r = info->hdr_len + sizeof(uint32_t);
        if (info->flag & FWTI_BLOCK_ASY)
                r += roundup2(fp->mode.wreqb.len, sizeof(uint32_t));

        if (r == sizeof(uint32_t)) {
                /* XXX */
                aprint_error_dev(sc->fc.dev, "Unknown tcode %d\n",
                    fp->mode.common.tcode);
                return -1;
        }

        if (r > dbch->xferq.psize) {
                aprint_error_dev(sc->fc.dev, "Invalid packet length %d\n", r);
                return -1;
                /* panic ? */
        }

        return r;
}

static void
fwohci_arcv_free_buf(struct fwohci_softc *sc, struct fwohci_dbch *dbch,
                     struct fwohcidb_tr *db_tr, int wake)
{
        struct fwohcidb *db = db_tr->db;
        struct fwohcidb_tr *bdb_tr = dbch->bottom;

        FWOHCI_DMA_CLEAR(db->db.desc.depend, 0xf);
        FWOHCI_DMA_WRITE(db->db.desc.res, dbch->xferq.psize);

        fwdma_sync_multiseg(dbch->am, bdb_tr->idx, bdb_tr->idx,
            BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
        FWOHCI_DMA_SET(bdb_tr->db[0].db.desc.depend, dbch->ndesc);

        fwdma_sync_multiseg(dbch->am, bdb_tr->idx, db_tr->idx,
            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
        dbch->bottom = db_tr;

        if (wake)
                OWRITE(sc, OHCI_DMACTL(dbch->off), OHCI_CNTL_DMA_WAKE);
}

static void
fwohci_arcv(struct fwohci_softc *sc, struct fwohci_dbch *dbch)
{
        struct fwohcidb_tr *db_tr;
        struct fw_pkt pktbuf, *fp;
        struct iovec vec[2];
        bus_addr_t m;
        bus_size_t n;
        u_int spd;
        uint32_t stat, status, event;
        uint8_t *ld;
        int nvec, resCount, len, plen, hlen, offset;
        const int psize = dbch->xferq.psize;

#if DIAGNOSTIC
        if (dbch->off != OHCI_ARQOFF &&
            dbch->off != OHCI_ARSOFF)
                panic("not async rx");
#endif

        mutex_enter(&dbch->xferq.q_mtx);
        db_tr = dbch->top;
        /* XXX we cannot handle a packet which lies in more than two buf */
        fwdma_sync_multiseg(dbch->am, db_tr->idx, db_tr->idx,
            BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
        status = FWOHCI_DMA_READ(db_tr->db[0].db.desc.res) >> OHCI_STATUS_SHIFT;
        resCount = FWOHCI_DMA_READ(db_tr->db[0].db.desc.res) & OHCI_COUNT_MASK;
        while (status & OHCI_CNTL_DMA_ACTIVE) {
#if 0
                if (dbch->off == OHCI_ARQOFF)
                        aprint_normal_dev(sc->fc.dev,
                            "buf 0x%08x, status 0x%04x, resCount 0x%04x\n",
                            db_tr->bus_addr, status, resCount);
#endif
                n = 0;
                len = psize - resCount;
                ld = (uint8_t *)db_tr->buf;
                if (dbch->pdb_tr == NULL) {
                        len -= dbch->buf_offset;
                        ld += dbch->buf_offset;
                        m = dbch->buf_offset;
                } else
                        m = 0;
                if (len > 0)
                        bus_dmamap_sync(sc->fc.dmat, db_tr->dma_map,
                            m, len, BUS_DMASYNC_POSTREAD);
                while (len > 0) {
                        if (dbch->pdb_tr != NULL) {
                                /* we have a fragment in previous buffer */
                                int rlen = 0;
                                void *buf;

                                if (dbch->buf_offset < 0) {
                                        /* split in header, pull up */
                                        char *p;

                                        rlen -= dbch->buf_offset;
                                        buf = (char *)dbch->pdb_tr->buf +
                                            psize - rlen;

                                        KASSERT(rlen <= sizeof(pktbuf));

                                        p = (char *)&pktbuf;
                                        memcpy(p, buf, rlen);
                                        p += rlen;
                                        /* this must be too long but harmless */
                                        rlen = sizeof(pktbuf) - rlen;
                                        memcpy(p, db_tr->buf, rlen);
                                        ld += rlen;
                                        len -= rlen;
                                        hlen = fwohci_arcv_swap(&pktbuf,
                                            sizeof(pktbuf));
                                        if (hlen <= 0) {
                                                aprint_error_dev(sc->fc.dev,
                                                    "hlen should be positive.");
                                                goto err;
                                        }
                                        offset = sizeof(pktbuf);
                                        vec[0].iov_base = (char *)&pktbuf;
                                        vec[0].iov_len = offset;
                                } else {
                                        /* split in payload */
                                        buf = (char *)dbch->pdb_tr->buf +
                                            dbch->buf_offset;
                                        rlen = psize - dbch->buf_offset;
                                        if (firewire_debug)
                                                printf("rlen=%d, offset=%d\n",
                                                    rlen, dbch->buf_offset);
                                        offset = rlen;
                                        vec[0].iov_base = buf;
                                        vec[0].iov_len = rlen;
                                }
                                fp = (struct fw_pkt *)vec[0].iov_base;
                                nvec = 1;
                        } else {
                                /* no fragment in previous buffer */
                                fp = (struct fw_pkt *)ld;
                                hlen = fwohci_arcv_swap(fp, len);
                                if (hlen == 0)
                                        goto err;
                                if (hlen < 0) {
                                        dbch->pdb_tr = db_tr;
                                        dbch->buf_offset -= psize;
                                        /* sanity check */
                                        if (resCount != 0)  {
                                                aprint_error_dev(sc->fc.dev,
                                                    "resCount=%d hlen=%d\n",
                                                    resCount, hlen);
                                                goto err;
                                        }
                                        goto out;
                                }
                                offset = 0;
                                nvec = 0;
                        }
                        plen = fwohci_get_plen(sc, dbch, fp) - offset;
                        if (plen < 0) {
                                /*
                                 * minimum header size + trailer =
                                 *     sizeof(fw_pkt) so this shouldn't happens
                                 */
                                aprint_error_dev(sc->fc.dev,
                                    "plen(%d) is negative! offset=%d\n",
                                    plen, offset);
                                goto err;
                        }
                        if (plen > 0) {
                                len -= plen;
                                if (len < 0) {
                                        dbch->pdb_tr = db_tr;
                                        if (firewire_debug)
                                                printf("split payload\n");
                                        /* sanity check */
                                        if (resCount != 0) {
                                                aprint_error_dev(sc->fc.dev,
                                                    "resCount=%d plen=%d"
                                                    " len=%d\n",
                                                    resCount, plen, len);
                                                goto err;
                                        }
                                        goto out;
                                }
                                vec[nvec].iov_base = ld;
                                vec[nvec].iov_len = plen;
                                nvec++;
                                ld += plen;
                        }
                        if (nvec == 0)
                                aprint_error_dev(sc->fc.dev, "nvec == 0\n");

/* DMA result-code will be written at the tail of packet */
                        stat = FWOHCI_DMA_READ(*(uint32_t *)(ld -
                                                sizeof(struct fwohci_trailer)));
#if 0
                        aprint_normal("plen: %d, stat %x\n", plen, stat);
#endif
                        spd = (stat >> 21) & 0x3;
                        event = (stat >> 16) & 0x1f;
                        switch (event) {
                        case FWOHCIEV_ACKPEND:
#if 0
                                aprint_normal(sc->fc.dev,
                                    "ack pending tcode=0x%x..\n",
                                    fp->mode.common.tcode);
#endif
                                /* fall through */
                        case FWOHCIEV_ACKCOMPL:
                        {
                                struct fw_rcv_buf rb;

                                vec[nvec - 1].iov_len -=
                                    sizeof(struct fwohci_trailer);
                                if (vec[nvec - 1].iov_len == 0)
                                        nvec--;
                                rb.fc = &sc->fc;
                                rb.vec = vec;
                                rb.nvec = nvec;
                                rb.spd = spd;
                                fw_rcv(&rb);
                                break;
                        }
                        case FWOHCIEV_BUSRST:
                                if ((sc->fc.status != FWBUSRESET) &&
                                    (sc->fc.status != FWBUSINIT))
                                        aprint_error_dev(sc->fc.dev,
                                            "got BUSRST packet!?\n");
                                break;
                        default:
                                aprint_error_dev(sc->fc.dev,
                                    "Async DMA Receive error err=%02x %s"
                                    " plen=%d offset=%d len=%d status=0x%08x"
                                    " tcode=0x%x, stat=0x%08x\n",
                                    event, fwohcicode[event], plen,
                                    (int)(ld - (uint8_t *)db_tr->buf - plen),
                                    len, OREAD(sc, OHCI_DMACTL(dbch->off)),
                                    fp->mode.common.tcode, stat);
#if 1 /* XXX */
                                goto err;
#endif
                                break;
                        }
                        if (dbch->pdb_tr != NULL) {
                                if (dbch->buf_offset < 0)
                                        bus_dmamap_sync(sc->fc.dmat,
                                            dbch->pdb_tr->dma_map,
                                            psize + dbch->buf_offset,
                                            0 - dbch->buf_offset,
                                            BUS_DMASYNC_PREREAD);
                                else
                                        bus_dmamap_sync(sc->fc.dmat,
                                            dbch->pdb_tr->dma_map,
                                            dbch->buf_offset,
                                            psize - dbch->buf_offset,
                                            BUS_DMASYNC_PREREAD);
                                fwohci_arcv_free_buf(sc, dbch, dbch->pdb_tr, 1);
                                dbch->pdb_tr = NULL;
                        }
                        dbch->buf_offset = ld - (uint8_t *)db_tr->buf;
                        n += (plen + offset);
                }
out:
                if (n > 0)
                        bus_dmamap_sync(sc->fc.dmat, db_tr->dma_map, m, n,
                            BUS_DMASYNC_PREREAD);

                if (resCount != 0) {
                        dbch->buf_offset = psize - resCount;
                        break;
                }

                /* done on this buffer */

                if (dbch->pdb_tr == NULL) {
                        fwohci_arcv_free_buf(sc, dbch, db_tr, 1);
                        dbch->buf_offset = 0;
                } else
                        if (dbch->pdb_tr != db_tr)
                                aprint_error_dev(sc->fc.dev,
                                    "pdb_tr != db_tr\n");
                dbch->top = STAILQ_NEXT(db_tr, link);

                db_tr = dbch->top;
                fwdma_sync_multiseg(dbch->am, db_tr->idx, db_tr->idx,
                    BUS_DMASYNC_POSTREAD | BUS_DMASYNC_POSTWRITE);
                status = FWOHCI_DMA_READ(db_tr->db[0].db.desc.res) >>
                    OHCI_STATUS_SHIFT;
                resCount = FWOHCI_DMA_READ(db_tr->db[0].db.desc.res)
                    & OHCI_COUNT_MASK;

                /* XXX check buffer overrun */

                /* XXX make sure DMA is not dead */
        }
        fwdma_sync_multiseg(dbch->am, db_tr->idx, db_tr->idx,
            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
        mutex_exit(&dbch->xferq.q_mtx);
        return;

err:
        aprint_error_dev(sc->fc.dev, "AR DMA status=%x, ",
            OREAD(sc, OHCI_DMACTL(dbch->off)));
        if (dbch->pdb_tr != NULL) {
                if (dbch->buf_offset < 0)
                        bus_dmamap_sync(sc->fc.dmat, dbch->pdb_tr->dma_map,
                            psize + dbch->buf_offset, 0 - dbch->buf_offset,
                            BUS_DMASYNC_PREREAD);
                else
                        bus_dmamap_sync(sc->fc.dmat, dbch->pdb_tr->dma_map,
                            dbch->buf_offset, psize - dbch->buf_offset,
                            BUS_DMASYNC_PREREAD);
                fwohci_arcv_free_buf(sc, dbch, dbch->pdb_tr, 1);
                dbch->pdb_tr = NULL;
        }
        /* skip until resCount != 0 */
        aprint_error(" skip buffer");
        while (resCount == 0) {
                aprint_error(" #");
                fwohci_arcv_free_buf(sc, dbch, db_tr, 0);
                db_tr = STAILQ_NEXT(db_tr, link);
                resCount = FWOHCI_DMA_READ(db_tr->db[0].db.desc.res)
                    & OHCI_COUNT_MASK;
        }
        aprint_error(" done\n");
        dbch->top = db_tr;
        dbch->buf_offset = psize - resCount;
        OWRITE(sc, OHCI_DMACTL(dbch->off), OHCI_CNTL_DMA_WAKE);
        fwdma_sync_multiseg(dbch->am, db_tr->idx, db_tr->idx,
            BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
        bus_dmamap_sync(sc->fc.dmat, db_tr->dma_map,
            0, db_tr->dma_map->dm_mapsize, BUS_DMASYNC_PREREAD);
        mutex_exit(&dbch->xferq.q_mtx);
}