bnx2x: Fix rare self-test failures

On rare occasions, self test link may fail since the link is
being sampled while it's still being stabilized.
To correct this behaviour, try to sample the link for 2 seconds
prior to declaring a failure.
Signed-off-by: NYaniv Rosner <yanivr@broadcom.com>
Signed-off-by: NYuval Mintz <yuvalmin@broadcom.com>
Signed-off-by: NAriel Elior <ariele@broadcom.com>
Signed-off-by: NEilon Greenstein <eilong@broadcom.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnx2x/bnx2x_ethtool.c

@@ -2379,8 +2379,8 @@ static void bnx2x_self_test(struct net_device *dev,
 			    struct ethtool_test *etest, u64 *buf)
 {
 	struct bnx2x *bp = netdev_priv(dev);
-	u8 is_serdes;
-	int rc;
+	u8 is_serdes, link_up;
+	int rc, cnt = 0;
 
 	if (bp->recovery_state != BNX2X_RECOVERY_DONE) {
 		netdev_err(bp->dev,
@@ -2402,20 +2402,17 @@ static void bnx2x_self_test(struct net_device *dev,
 	}
 
 	is_serdes = (bp->link_vars.link_status & LINK_STATUS_SERDES_LINK) > 0;
-
+	link_up = bp->link_vars.link_up;
 	/* offline tests are not supported in MF mode */
 	if ((etest->flags & ETH_TEST_FL_OFFLINE) && !IS_MF(bp)) {
 		int port = BP_PORT(bp);
 		u32 val;
-		u8 link_up;
 
 		/* save current value of input enable for TX port IF */
 		val = REG_RD(bp, NIG_REG_EGRESS_UMP0_IN_EN + port*4);
 		/* disable input for TX port IF */
 		REG_WR(bp, NIG_REG_EGRESS_UMP0_IN_EN + port*4, 0);
 
-		link_up = bp->link_vars.link_up;
-
 		bnx2x_nic_unload(bp, UNLOAD_NORMAL, false);
 		rc = bnx2x_nic_load(bp, LOAD_DIAG);
 		if (rc) {
@@ -2477,7 +2474,13 @@ static void bnx2x_self_test(struct net_device *dev,
 		etest->flags |= ETH_TEST_FL_FAILED;
 	}
 
-	if (bnx2x_link_test(bp, is_serdes) != 0) {
+	if (link_up) {
+		cnt = 100;
+		while (bnx2x_link_test(bp, is_serdes) && --cnt)
+			msleep(20);
+	}
+
+	if (!cnt) {
 		if (!IS_MF(bp))
 			buf[6] = 1;
 		else