next_txbd
txbdp_tstamp = txbdp = next_txbd(txbdp, base,
txbdp = next_txbd(txbdp, base, tx_queue->tx_ring_size);
tx_queue->cur_tx = next_txbd(txbdp, base, tx_queue->tx_ring_size);
txbdp = next_txbd(txbdp_start, base, tx_queue->tx_ring_size);
txbdp = next_txbd(txbdp, base, tx_queue->tx_ring_size);
txbdp = next_txbd(txbdp, base, tx_queue->tx_ring_size);
next = next_txbd(bdp, base, tx_ring_size);
bdp = next_txbd(bdp, base, tx_ring_size);
bdp = next_txbd(bdp, base, tx_ring_size);