CPSW_CPDMA_RX_HDP
bus_space_write_4(sc->sc_bst, sc->sc_bsh, CPSW_CPDMA_RX_HDP(0),
stat = bus_space_read_4(sc->sc_bst, sc->sc_bsh, CPSW_CPDMA_RX_HDP(0));
bus_space_write_4(sc->sc_bst, sc->sc_bsh, CPSW_CPDMA_RX_HDP(i), 0);
bus_space_write_4(sc->sc_bst, sc->sc_bsh, CPSW_CPDMA_RX_HDP(0), cpsw_rxdesc_paddr(sc, 0));