cpsw_rxdesc_paddr
cpsw_write_4(sc, CPSW_CPDMA_RX_HDP(0), cpsw_rxdesc_paddr(sc, 0));
cpsw_rxdesc_paddr(sc, i));
cpsw_set_rxdesc_next(sc, h, cpsw_rxdesc_paddr(sc, i));