virtio_net: drop config_enable

Now that virtio core ensures config changes don't arrive during probing,
drop config_enable flag in virtio net.
On removal, flush is now sufficient to guarantee that no change work is
queued.

This help simplify the driver, and will allow setting DRIVER_OK earlier
without losing config change notifications.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 59caa06..743fb04 100644 (file)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -123,9 +123,6 @@ struct virtnet_info {
        /* Host can handle any s/g split between our header and packet data */
        bool any_header_sg;
 
-       /* enable config space updates */
-       bool config_enable;
-
        /* Active statistics */
        struct virtnet_stats __percpu *stats;
 
@@ -1408,9 +1405,6 @@ static void virtnet_config_changed_work(struct work_struct *work)
        u16 v;
 
        mutex_lock(&vi->config_lock);
-       if (!vi->config_enable)
-               goto done;
-
        if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
                                 struct virtio_net_config, status, &v) < 0)
                goto done;
@@ -1758,7 +1752,6 @@ static int virtnet_probe(struct virtio_device *vdev)
        }
 
        mutex_init(&vi->config_lock);
-       vi->config_enable = true;
        INIT_WORK(&vi->config_work, virtnet_config_changed_work);
 
        /* If we can receive ANY GSO packets, we must allocate large ones. */
@@ -1875,17 +1868,13 @@ static void virtnet_remove(struct virtio_device *vdev)
 
        unregister_hotcpu_notifier(&vi->nb);
 
-       /* Prevent config work handler from accessing the device. */
-       mutex_lock(&vi->config_lock);
-       vi->config_enable = false;
-       mutex_unlock(&vi->config_lock);
+       /* Make sure no work handler is accessing the device. */
+       flush_work(&vi->config_work);
 
        unregister_netdev(vi->dev);
 
        remove_vq_common(vi);
 
-       flush_work(&vi->config_work);
-
        free_percpu(vi->stats);
        free_netdev(vi->dev);
 }
@@ -1898,10 +1887,8 @@ static int virtnet_freeze(struct virtio_device *vdev)
 
        unregister_hotcpu_notifier(&vi->nb);
 
-       /* Prevent config work handler from accessing the device */
-       mutex_lock(&vi->config_lock);
-       vi->config_enable = false;
-       mutex_unlock(&vi->config_lock);
+       /* Make sure no work handler is accessing the device */
+       flush_work(&vi->config_work);
 
        netif_device_detach(vi->dev);
        cancel_delayed_work_sync(&vi->refill);
@@ -1916,8 +1903,6 @@ static int virtnet_freeze(struct virtio_device *vdev)
 
        remove_vq_common(vi);
 
-       flush_work(&vi->config_work);
-
        return 0;
 }
 
@@ -1941,10 +1926,6 @@ static int virtnet_restore(struct virtio_device *vdev)
 
        netif_device_attach(vi->dev);
 
-       mutex_lock(&vi->config_lock);
-       vi->config_enable = true;
-       mutex_unlock(&vi->config_lock);
-
        rtnl_lock();
        virtnet_set_queues(vi, vi->curr_queue_pairs);
        rtnl_unlock();