CPSW_CPDMA_RX_HDP
cpsw_write_4(sc, CPSW_CPDMA_RX_HDP(0), cpsw_rxdesc_paddr(sc, 0));
stat = cpsw_read_4(sc, CPSW_CPDMA_RX_HDP(0));
cpsw_write_4(sc, CPSW_CPDMA_RX_HDP(i), 0);