MGB_DMAC_RX_INTR_ENBL
dmac_enable |= MGB_DMAC_RX_INTR_ENBL(i);
CSR_WRITE_REG(sc, MGB_DMAC_INTR_STS, MGB_DMAC_RX_INTR_ENBL(qid));
CSR_WRITE_REG(sc, MGB_DMAC_INTR_ENBL_SET, MGB_DMAC_RX_INTR_ENBL(qid));