mlx4_en: reconfiguring mac address.

When Mac address is removed from one port of the CX2 device, the other device
should reconfigure its Mac.
This fixes an issue with failover, when both ports have the same Mac address,
and one of the ports, is closed, the second one stops receiving traffic.
(bugzilla #1965 at bugs.openfabrics.org)
Signed-off-by: Yevgeny Petrilin <yevgenyp@mellanox.co.il>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/mlx4/en_netdev.c

@@ -513,6 +513,10 @@ static void mlx4_en_do_get_stats(struct work_struct *work)
 
 		queue_delayed_work(mdev->workqueue, &priv->stats_task, STATS_DELAY);
 	}
+	if (mdev->mac_removed[MLX4_MAX_PORTS + 1 - priv->port]) {
+		queue_work(mdev->workqueue, &priv->mac_task);
+		mdev->mac_removed[MLX4_MAX_PORTS + 1 - priv->port] = 0;
+	}
 	mutex_unlock(&mdev->state_lock);
 }
 
@@ -653,6 +657,7 @@ int mlx4_en_start_port(struct net_device *dev)
 		en_err(priv, "Failed setting port mac\n");
 		goto tx_err;
 	}
+	mdev->mac_removed[priv->port] = 0;
 
 	/* Init port */
 	en_dbg(HW, priv, "Initializing port\n");
@@ -709,6 +714,7 @@ void mlx4_en_stop_port(struct net_device *dev)
 
 	/* Unregister Mac address for the port */
 	mlx4_unregister_mac(mdev->dev, priv->port, priv->mac_index);
+	mdev->mac_removed[priv->port] = 1;
 
 	/* Free TX Rings */
 	for (i = 0; i < priv->tx_ring_num; i++) {

drivers/net/mlx4/mlx4_en.h

@@ -341,6 +341,7 @@ struct mlx4_en_dev {
 	struct mlx4_mr		mr;
 	u32                     priv_pdn;
 	spinlock_t              uar_lock;
+	u8			mac_removed[MLX4_MAX_PORTS + 1];
 };