[PATCH v4 08/25] virtio-net: drop config_mutex

Michael S. Tsirkin
2014-10-13T07:50:23Z

config_mutex served two purposes: prevent multiple concurrent config
change handlers, and synchronize access to config_enable flag.

Since commit dbf2576e37da0fcc7aacbfbb9fd5d3de7888a3c1
workqueue: make all workqueues non-reentrant
all workqueues are non-reentrant, and config_enable
is now gone.

Get rid of the unnecessary lock.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
---
drivers/net/virtio_net.c | 7 +------
1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 743fb04..23e4a69 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -132,9 +132,6 @@ struct virtnet_info {
/* Work struct for config space updates */
struct work_struct config_work;

- /* Lock for config space updates */
- struct mutex config_lock;
-
/* Does the affinity hint is set for virtqueues? */
bool affinity_hint_set;

@@ -1404,7 +1401,6 @@ static void virtnet_config_changed_work(struct work_struct *work)
container_of(work, struct virtnet_info, config_work);
u16 v;

- mutex_lock(&vi->config_lock);
if (virtio_cread_feature(vi->vdev, VIRTIO_NET_F_STATUS,
struct virtio_net_config, status, &v) < 0)
goto done;
@@ -1430,7 +1426,7 @@ static void virtnet_config_changed_work(struct work_struct *work)
netif_tx_stop_all_queues(vi->dev);
}
done:
- mutex_unlock(&vi->config_lock);
+ return;
}

static void virtnet_config_changed(struct virtio_device *vdev)
@@ -1751,7 +1747,6 @@ static int virtnet_probe(struct virtio_device *vdev)
u64_stats_init(&virtnet_stats->rx_syncp);
}

- mutex_init(&vi->config_lock);
INIT_WORK(&vi->config_work, virtnet_config_changed_work);

/* If we can receive ANY GSO packets, we must allocate large ones. */
--
MST