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: NAlexander Duyck <alexander.h.duyck@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: NJeff 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;

drivers/net/igb/e1000_defines.h

@@ -257,6 +257,7 @@
 #define E1000_PCS_LCTL_FDV_FULL          8
 #define E1000_PCS_LCTL_FSD               0x10
 #define E1000_PCS_LCTL_FORCE_LINK        0x20
+#define E1000_PCS_LCTL_FORCE_FCTRL       0x80
 #define E1000_PCS_LCTL_AN_ENABLE         0x10000
 #define E1000_PCS_LCTL_AN_RESTART        0x20000
 #define E1000_PCS_LCTL_AN_TIMEOUT        0x40000