ixgbe: Don't return error in flow control configuration if FC is off

When flow control is disabled, an invalid low/high watermark configuration
should not matter.

Signed-off-by: Peter P Waskiewicz Jr <peter.p.waskiewicz.jr@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ixgbe/ixgbe_82598.c

@@ -381,9 +381,11 @@ static s32 ixgbe_setup_fc_82598(struct ixgbe_hw *hw, s32 packetbuf_num)
 	 * because it causes the controller to just blast out fc packets.
 	 */
 	if (!hw->fc.low_water || !hw->fc.high_water || !hw->fc.pause_time) {
-		hw_dbg(hw, "Invalid water mark configuration\n");
-		ret_val = IXGBE_ERR_INVALID_LINK_SETTINGS;
-		goto out;
+		if (hw->fc.requested_mode != ixgbe_fc_none) {
+			hw_dbg(hw, "Invalid water mark configuration\n");
+			ret_val = IXGBE_ERR_INVALID_LINK_SETTINGS;
+			goto out;
+		}
 	}
 
 	/*

drivers/net/ixgbe/ixgbe_common.c

@@ -1907,9 +1907,11 @@ s32 ixgbe_setup_fc_generic(struct ixgbe_hw *hw, s32 packetbuf_num)
 	 * because it causes the controller to just blast out fc packets.
 	 */
 	if (!hw->fc.low_water || !hw->fc.high_water || !hw->fc.pause_time) {
-		hw_dbg(hw, "Invalid water mark configuration\n");
-		ret_val = IXGBE_ERR_INVALID_LINK_SETTINGS;
-		goto out;
+		if (hw->fc.requested_mode != ixgbe_fc_none) {
+			hw_dbg(hw, "Invalid water mark configuration\n");
+			ret_val = IXGBE_ERR_INVALID_LINK_SETTINGS;
+			goto out;
+		}
 	}
 
 	/*