VTE_RX_RING_SZ
bzero(desc, VTE_RX_RING_SZ);
error = bus_dmamap_create(sc->sc_dmat, VTE_RX_RING_SZ, 1,
VTE_RX_RING_SZ, 0, BUS_DMA_NOWAIT, &sc->vte_cdata.vte_rx_ring_map);
error = bus_dmamem_alloc(sc->sc_dmat, VTE_RX_RING_SZ, ETHER_ALIGN,
nsegs, VTE_RX_RING_SZ, (caddr_t *)&sc->vte_cdata.vte_rx_ring,
sc->vte_cdata.vte_rx_ring, VTE_RX_RING_SZ, NULL, BUS_DMA_WAITOK);