ral_dma_region_free
ral_dma_region_free(sc, &ring->dr_txbuf[i]);
ral_dma_region_free(sc, &ring->dr_desc);
ral_dma_region_free(sc, &ring->dr_desc);
ral_dma_region_free(sc, &ring->dr_txbuf[i]);
ral_dma_region_free(sc, &ring->dr_rxbuf[i]);
ral_dma_region_free(sc, &ring->dr_desc);
ral_dma_region_free(sc, &ring->dr_desc);
ral_dma_region_free(sc, &ring->dr_rxbuf[i]);