ixgbe: fix race when setting advertised speed

Following commands:

modprobe ixgbe
ifconfig ethX up
ethtool -s ethX advertise 0x020

can lead to "setup link failed with code -14" error due to the setup_link
call racing with the SFP detection routine in the watchdog.

This patch resolves this issue by protecting the setup_link call with check
for __IXGBE_IN_SFP_INIT.

Reported-by: Scott Harrison <scoharr2@cisco.com>
Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com>
Tested-by: Phil Schmitt <phillip.j.schmitt@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/ixgbe/ixgbe_ethtool.c

@@ -342,12 +342,16 @@ static int ixgbe_set_settings(struct net_device *netdev,
 		if (old == advertised)
 			return err;
 		/* this sets the link speed and restarts auto-neg */
+		while (test_and_set_bit(__IXGBE_IN_SFP_INIT, &adapter->state))
+			usleep_range(1000, 2000);
+
 		hw->mac.autotry_restart = true;
 		err = hw->mac.ops.setup_link(hw, advertised, true);
 		if (err) {
 			e_info(probe, "setup link failed with code %d\n", err);
 			hw->mac.ops.setup_link(hw, old, true);
 		}
+		clear_bit(__IXGBE_IN_SFP_INIT, &adapter->state);
 	} else {
 		/* in this case we currently only support 10Gb/FULL */
 		u32 speed = ethtool_cmd_speed(ecmd);