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

From: Michael S. Tsirkin
Date: Fri Nov 05 2010 - 04:45:52 EST


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@xxxxxxxxxx>

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

> ---
> 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;
--
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