i40e: don't restart nway if autoneg not supported

On link types that do not support autoneg, we cannot attempt to restart
nway negotiation. This results in a dead link that requires a power
cycle to remedy.

Fix this by saving off the autoneg state and checking this value before
we try to restart nway.
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

drivers/net/ethernet/intel/i40e/i40e_ethtool.c

@@ -1335,6 +1335,7 @@ static int i40e_set_pauseparam(struct net_device *netdev,
 	i40e_status status;
 	u8 aq_failures;
 	int err = 0;
+	u32 is_an;
 
 	/* Changing the port's flow control is not supported if this isn't the
 	 * port's controlling PF
@@ -1347,15 +1348,14 @@ static int i40e_set_pauseparam(struct net_device *netdev,
 	if (vsi != pf->vsi[pf->lan_vsi])
 		return -EOPNOTSUPP;
 
-	if (pause->autoneg != ((hw_link_info->an_info & I40E_AQ_AN_COMPLETED) ?
-	    AUTONEG_ENABLE : AUTONEG_DISABLE)) {
+	is_an = hw_link_info->an_info & I40E_AQ_AN_COMPLETED;
+	if (pause->autoneg != is_an) {
 		netdev_info(netdev, "To change autoneg please use: ethtool -s <dev> autoneg <on|off>\n");
 		return -EOPNOTSUPP;
 	}
 
 	/* If we have link and don't have autoneg */
-	if (!test_bit(__I40E_DOWN, pf->state) &&
-	    !(hw_link_info->an_info & I40E_AQ_AN_COMPLETED)) {
+	if (!test_bit(__I40E_DOWN, pf->state) && !is_an) {
 		/* Send message that it might not necessarily work*/
 		netdev_info(netdev, "Autoneg did not complete so changing settings may not result in an actual change.\n");
 	}
@@ -1406,7 +1406,7 @@ static int i40e_set_pauseparam(struct net_device *netdev,
 		err = -EAGAIN;
 	}
 
-	if (!test_bit(__I40E_DOWN, pf->state)) {
+	if (!test_bit(__I40E_DOWN, pf->state) && is_an) {
 		/* Give it a little more time to try to come back */
 		msleep(75);
 		if (!test_bit(__I40E_DOWN, pf->state))