net/mlx4_en: Fix improper use of "port" parameter in mlx4_en_event

Port is used as an array index before we know if that is proper.

For example, in the catas event case, port is zero; however,
the port index should lie in the range (1..2).

Fix this by using 'port' only in the events where it is of interest.

Test for port out of range in the default (unhandled event) case,
and do not output a message if it is not an ethernet port.

Signed-off-by: Jack Morgenstein <jackm@dev.mellanox.co.il>
Reviewed-by: Or Gerlitz <ogerlitz@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/mellanox/mlx4/en_main.c

@@ -136,13 +136,12 @@ static void mlx4_en_event(struct mlx4_dev *dev, void *endev_ptr,
 	struct mlx4_en_dev *mdev = (struct mlx4_en_dev *) endev_ptr;
 	struct mlx4_en_priv *priv;
 
-	if (!mdev->pndev[port])
-		return;
-
-	priv = netdev_priv(mdev->pndev[port]);
 	switch (event) {
 	case MLX4_DEV_EVENT_PORT_UP:
 	case MLX4_DEV_EVENT_PORT_DOWN:
+		if (!mdev->pndev[port])
+			return;
+		priv = netdev_priv(mdev->pndev[port]);
 		/* To prevent races, we poll the link state in a separate
 		  task rather than changing it here */
 		priv->link_state = event;
@@ -154,7 +153,10 @@ static void mlx4_en_event(struct mlx4_dev *dev, void *endev_ptr,
 		break;
 
 	default:
-		mlx4_warn(mdev, "Unhandled event: %d\n", event);
+		if (port < 1 || port > dev->caps.num_ports ||
+		    !mdev->pndev[port])
+			return;
+		mlx4_warn(mdev, "Unhandled event %d for port %d\n", event, port);
 	}
 }