DP83867_RXFCFG
val_rxcfg = phy_read_mmd(phydev, DP83867_DEVADDR, DP83867_RXFCFG);
phy_write_mmd(phydev, DP83867_DEVADDR, DP83867_RXFCFG, val_rxcfg);
value = phy_read_mmd(phydev, DP83867_DEVADDR, DP83867_RXFCFG);