e1000e: Fix check_for_link return value with autoneg off

BugLink: https://bugs.launchpad.net/bugs/1775771

[ Upstream commit 4e7dc08e ]

When autoneg is off, the .check_for_link callback functions clear the
get_link_status flag and systematically return a "pseudo-error". This means
that the link is not detected as up until the next execution of the
e1000_watchdog_task() 2 seconds later.

Fixes: 19110cfb ("e1000e: Separate signaling for link check/link up")
Signed-off-by: Benjamin Poirier <bpoirier@suse.com>
Acked-by: Sasha Neftin <sasha.neftin@intel.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

drivers/net/ethernet/intel/e1000e/ich8lan.c

@@ -1574,7 +1574,7 @@ static s32 e1000_check_for_copper_link_ich8lan(struct e1000_hw *hw)
 	 * we have already determined whether we have link or not.
 	 */
 	if (!mac->autoneg)
-		return -E1000_ERR_CONFIG;
+		return 1;
 
 	/* Auto-Neg is enabled.  Auto Speed Detection takes care
 	 * of MAC speed/duplex configuration.  So we only need to

drivers/net/ethernet/intel/e1000e/mac.c

@@ -450,7 +450,7 @@ s32 e1000e_check_for_copper_link(struct e1000_hw *hw)
 	 * we have already determined whether we have link or not.
 	 */
 	if (!mac->autoneg)
-		return -E1000_ERR_CONFIG;
+		return 1;
 
 	/* Auto-Neg is enabled.  Auto Speed Detection takes care
 	 * of MAC speed/duplex configuration.  So we only need to