igb: fixes 82576 serdes init to correctly support manual flow control changes

This patch changes the PCS configuration for serdes so that the flow
control options change be set via the ethtool -A option.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/net/igb/e1000_82575.c

@@ -1136,6 +1136,12 @@ static s32 igb_setup_fiber_serdes_link_82575(struct e1000_hw *hw)
 		       E1000_PCS_LCTL_FORCE_LINK;     /* Force Link */
 		hw_dbg("Configuring Forced Link; PCS_LCTL = 0x%08X\n", reg);
 	}
+
+	if (hw->mac.type == e1000_82576) {
+		reg |= E1000_PCS_LCTL_FORCE_FCTRL;
+		igb_force_mac_fc(hw);
+	}
+
 	wr32(E1000_PCS_LCTL, reg);
 
 	return 0;