be2net: fix link failure after ethtool offline test

BugLink: https://bugs.launchpad.net/bugs/1838467

[ Upstream commit 2e5db6eb ]

Certain cards in conjunction with certain switches need a little more
time for link setup that results in ethtool link test failure after
offline test. Patch adds a loop that waits for a link setup finish.

Changes in v2:
- added fixes header

Fixes: 4276e47e ("be2net: Add link test to list of ethtool self tests.")
Signed-off-by: Petr Oros <poros@redhat.com>
Reviewed-by: Ivan Vecera <ivecera@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

drivers/net/ethernet/emulex/benet/be_ethtool.c

@@ -868,7 +868,7 @@ static void be_self_test(struct net_device *netdev, struct ethtool_test *test,
 			 u64 *data)
 {
 	struct be_adapter *adapter = netdev_priv(netdev);
-	int status;
+	int status, cnt;
 	u8 link_status = 0;
 
 	if (adapter->function_caps & BE_FUNCTION_CAPS_SUPER_NIC) {
@@ -879,6 +879,9 @@ static void be_self_test(struct net_device *netdev, struct ethtool_test *test,
 
 	memset(data, 0, sizeof(u64) * ETHTOOL_TESTS_NUM);
 
+	/* check link status before offline tests */
+	link_status = netif_carrier_ok(netdev);
+
 	if (test->flags & ETH_TEST_FL_OFFLINE) {
 		if (be_loopback_test(adapter, BE_MAC_LOOPBACK, &data[0]) != 0)
 			test->flags |= ETH_TEST_FL_FAILED;
@@ -899,13 +902,26 @@ static void be_self_test(struct net_device *netdev, struct ethtool_test *test,
 		test->flags |= ETH_TEST_FL_FAILED;
 	}
 
-	status = be_cmd_link_status_query(adapter, NULL, &link_status, 0);
+	/* link status was down prior to test */
+	if (!link_status) {
+		test->flags |= ETH_TEST_FL_FAILED;
+		data[4] = 1;
+		return;
+	}
+
+	for (cnt = 10; cnt; cnt--) {
+		status = be_cmd_link_status_query(adapter, NULL, &link_status,
+						  0);
 		if (status) {
 			test->flags |= ETH_TEST_FL_FAILED;
 			data[4] = -1;
-	} else if (!link_status) {
-		test->flags |= ETH_TEST_FL_FAILED;
-		data[4] = 1;
+			break;
+		}
+
+		if (link_status)
+			break;
+
+		msleep_interruptible(500);
 	}
 }