GMAC_DMA_CHAN0_INTR_ENABLE
WR4(sc, GMAC_DMA_CHAN0_INTR_ENABLE,
WR4(sc, GMAC_DMA_CHAN0_INTR_ENABLE, 0);
dma_status &= RD4(sc, GMAC_DMA_CHAN0_INTR_ENABLE);