BGMAC_DMA_TX_STATUS
empty_slot = bgmac_read(bgmac, ring->mmio_base + BGMAC_DMA_TX_STATUS);
val = bgmac_read(bgmac, ring->mmio_base + BGMAC_DMA_TX_STATUS);
ring->mmio_base + BGMAC_DMA_TX_STATUS,
val = bgmac_read(bgmac, ring->mmio_base + BGMAC_DMA_TX_STATUS);