NGBE_MAC_RX_FLOW_CTRL_RFE
mflcn &= ~NGBE_MAC_RX_FLOW_CTRL_RFE;
mflcn |= NGBE_MAC_RX_FLOW_CTRL_RFE;
NGBE_MAC_RX_FLOW_CTRL_RFE, NGBE_MAC_RX_FLOW_CTRL_RFE);