virtio: flush buffers on open Fix bug found by Christian Borntraeger: if the other side fills all the registered network buffers before we enable NAPI, we will never get an interrupt. The simplest fix is to process the input queue once on open. Signed-off-by: Rusty Russell --- drivers/net/virtio_net.c | 7 +++++++ 1 file changed, 7 insertions(+) diff -r e5c15ec783ec drivers/net/virtio_net.c --- a/drivers/net/virtio_net.c Thu Jan 24 12:07:05 2008 +1100 +++ b/drivers/net/virtio_net.c Thu Jan 24 12:19:21 2008 +1100 @@ -283,6 +283,13 @@ static int virtnet_open(struct net_devic struct virtnet_info *vi = netdev_priv(dev); napi_enable(&vi->napi); + + /* If all buffers were filled by other side before we napi_enabled, we + * won't get another interrupt, so process any outstanding packets + * now. virtnet_poll wants re-enable the queue, so we disable here. */ + vi->rvq->vq_ops->disable_cb(vi->rvq); + netif_rx_schedule(vi->dev, &vi->napi); + return 0; }