CPSW_CPDMA_TX_CP
if (cpsw_read_4(sc, CPSW_CPDMA_TX_CP(0)) == 0xfffffffc)
txchan, cpsw_read_4(sc, CPSW_CPDMA_TX_CP(txchan)));
cpsw_read_4(sc, CPSW_CPDMA_TX_CP(0)));
#define CP_OFFSET (CPSW_CPDMA_TX_CP(0) - CPSW_CPDMA_TX_HDP(0))
cpsw_write_4(sc, CPSW_CPDMA_TX_CP(i), 0);