CPSW_CPDMA_RX_FREEBUFFER
cpsw_write_4(sc, CPSW_CPDMA_RX_FREEBUFFER(0), added);
cpsw_write_4(sc, CPSW_CPDMA_RX_FREEBUFFER(0), 0);
cpsw_write_4(sc, CPSW_CPDMA_RX_FREEBUFFER(0), sc->rx.active_queue_len);