CPSW_CPDMA_TX_HDP
cpsw_write_4(sc, CPSW_CPDMA_TX_HDP(0), 0);
if (cpsw_read_4(sc, CPSW_CPDMA_TX_HDP(0)) == 0) {
cpsw_write_4(sc, CPSW_CPDMA_TX_HDP(0),
cpsw_read_4(sc, CPSW_CPDMA_TX_HDP(0)), 0, 0);
stat = cpsw_read_4(sc, CPSW_CPDMA_TX_HDP(0));
cpsw_read_4(sc, CPSW_CPDMA_TX_HDP(0)), txstart, eopi);
cpsw_write_4(sc, CPSW_CPDMA_TX_HDP(0),
cpsw_write_4(sc, CPSW_CPDMA_TX_HDP(i), 0);