MALO_TX_RING_COUNT
if (sc->sc_txring.queued >= MALO_TX_RING_COUNT - 1) {
sc->sc_txring.cur = (sc->sc_txring.cur + 1) % MALO_TX_RING_COUNT;
sc->sc_txring.cur = (sc->sc_txring.cur + 1) % MALO_TX_RING_COUNT;
malo_alloc_tx_ring(sc, &sc->sc_txring, MALO_TX_RING_COUNT);