[PATCH net 1/2] virtio_net: fix possible dim status unrecoverable

[Heng Qi]

When the dim worker is scheduled, if it no longer needs to issue
commands, dim may not be able to return to the working state later.

For example, the following single queue scenario:
  1. The dim worker of rxq0 is scheduled, and the dim status is
     changed to DIM_APPLY_NEW_PROFILE;
  2. dim is disabled or parameters have not been modified;
  3. virtnet_rx_dim_work exits directly;

Then, even if net_dim is invoked again, it cannot work because the
state is not restored to DIM_START_MEASURE.

Fixes: 6208799553a8 ("virtio-net: support rx netdim")
Signed-off-by: Heng Qi <hen...@linux.alibaba.com>
---
 drivers/net/virtio_net.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 4e1a0fc0d555..1cad06cef230 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -4417,9 +4417,9 @@ static void virtnet_rx_dim_work(struct work_struct *work)
                if (err)
                        pr_debug("%s: Failed to send dim parameters on rxq%d\n",
                                 dev->name, qnum);
-               dim->state = DIM_START_MEASURE;
        }
 out:
+       dim->state = DIM_START_MEASURE;
        mutex_unlock(&rq->dim_lock);
 }
 
-- 
2.32.0.3.g01195cf9f