IXGBE_FCCFG
fccfg_reg = IXGBE_READ_REG(hw, IXGBE_FCCFG);
IXGBE_WRITE_REG(hw, IXGBE_FCCFG, fccfg_reg);
IXGBE_WRITE_REG(hw, IXGBE_FCCFG, IXGBE_FCCFG_TFCE_PRIORITY);
u32 fccfg = IXGBE_READ_REG(hw, IXGBE_FCCFG);