Re: [V2 PATCH] virtio-net: init link state correctly

["Michael S. Tsirkin" <mst@redhat.com>]

On Fri, Nov 05, 2010 at 10:50:08AM +0800, Jason Wang wrote:
> 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.
> 
> Signed-off-by: Jason Wang <jasowang@redhat.com>

Acked-by: Michael S. Tsirkin <mst@redhat.com>

> ---
>  drivers/net/virtio_net.c |   12 +++++++++---
>  1 files changed, 9 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index bb6b67f..b6d4028 100644
> --- 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;