SDMA_INTR_TXBUF
SDMA_INTR_TXBUF(sc->sc_unit) |
if (icause & SDMA_INTR_TXBUF(sc->sc_unit)) {
icause &= ~SDMA_INTR_TXBUF(sc->sc_unit);
sdma_imask |= SDMA_INTR_TXBUF(sc->sc_unit);
sdma_imask &= ~SDMA_INTR_TXBUF(sc->sc_unit);