can: switch carrier on if device was stopped while in bus-off state

This patch fixes a problem when a device is stopped while in the
bus-off state. Then the carrier remains off forever.

Signed-off-by: Kurt Van Dijck <kurt.van.dijck@skynet.be>
Signed-off-by: Wolfgang Grandegger <wg@grandegger.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/can/dev.c

@@ -473,6 +473,10 @@ int open_candev(struct net_device *dev)
 		return -EINVAL;
 	}
 
+	/* Switch carrier on if device was stopped while in bus-off state */
+	if (!netif_carrier_ok(dev))
+		netif_carrier_on(dev);
+
 	setup_timer(&priv->restart_timer, can_restart, (unsigned long)dev);
 
 	return 0;