AE_TXS_COUNT_DEFAULT
sc->txs_cur = (sc->txs_cur + 1) % AE_TXS_COUNT_DEFAULT;
AE_TXS_COUNT_DEFAULT * 4, BUS_DMA_WAITOK | BUS_DMA_ZERO,
sc->txs_ack = (sc->txs_ack + 1) % AE_TXS_COUNT_DEFAULT;
AE_WRITE_2(sc, AE_TXS_COUNT_REG, AE_TXS_COUNT_DEFAULT);