next_txidx
sc->tx_desc_head = next_txidx(sc, sc->tx_desc_head);
last_idx = next_txidx(sc, bmap->last_desc_idx);
idx = next_txidx(sc, idx);
sc->tx_desc_tail = next_txidx(sc, sc->tx_desc_tail);
sc->tx_map_tail = next_txidx(sc, sc->tx_map_tail);
sc->tx_map_head = next_txidx(sc, sc->tx_map_head);
nidx = next_txidx(sc, idx);
idx = next_txidx(sc, idx);
nidx = next_txidx(sc, idx);
sc->tx_idx_head = next_txidx(sc, sc->tx_idx_head);
sc->tx_idx_tail = next_txidx(sc, sc->tx_idx_tail);
nidx = next_txidx(sc, idx);
sc->tx_idx_head = next_txidx(sc, sc->tx_idx_head);
sc->tx_idx_tail = next_txidx(sc, sc->tx_idx_tail);