dbdma_setcmd
dbdma_setcmd(cp, (OUTPUT_LAST | INTR_ALWAYS | WAIT_IFCLR), len, baddr, 0);
dbdma_setcmd(cp, (INPUT_LAST | INTR_ALWAYS), RX_BUFLEN,
dbdma_setcmd(&bp->tx_cmds[N_TX_RING],
dbdma_setcmd(&bp->rx_cmds[N_RX_RING],
dbdma_setcmd(&bp->tx_cmds[i], DBDMA_STOP, 0, 0, 0);