virtio-net: init link state correctly

For device that supports VIRTIO_NET_F_STATUS, there's no need to assume the link is up and we need to call nerif_carrier_off() before querying device status, otherwise we may get wrong operstate after diver was loaded because the link watch event was not fired as expected. For device that does not support VIRITO_NET_F_STATUS, we could not get its status through virtnet_update_status() and what we can only do is always assuming the link is up. Acked-by: Michael S. Tsirkin <[email protected]> Signed-off-by: Jason Wang <[email protected]> Signed-off-by: Rusty Russell <[email protected]> Signed-off-by: David S. Miller <[email protected]>
yshchan · Nov 12, 2010 · 167c25e · 167c25e
1 parent 75e6047
commit 167c25e
Showing 1 changed file with 9 additions and 3 deletions.
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
@@ -986,9 +986,15 @@ static int virtnet_probe(struct virtio_device *vdev)
 		goto unregister;
 	}
 
-	vi->status = VIRTIO_NET_S_LINK_UP;
-	virtnet_update_status(vi);
-	netif_carrier_on(dev);
+	/* Assume link up if device can't report link status,
+	   otherwise get link status from config. */
+	if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_STATUS)) {
+		netif_carrier_off(dev);
+		virtnet_update_status(vi);
+	} else {
+		vi->status = VIRTIO_NET_S_LINK_UP;
+		netif_carrier_on(dev);
+	}
 
 	pr_debug("virtnet: registered device %s\n", dev->name);
 	return 0;