IXGBE_FCTRL_RFCE
fctrl_reg &= ~(IXGBE_FCTRL_RFCE | IXGBE_FCTRL_RPFCE);
fctrl_reg |= IXGBE_FCTRL_RFCE;
fctrl_reg |= IXGBE_FCTRL_RFCE;
reg &= ~(IXGBE_FCTRL_RPFCE | IXGBE_FCTRL_RFCE);
flow_rx = !!(frctl & IXGBE_FCTRL_RFCE);