[PATCH] media: ov9734: hold lock to check streaming state

[PATCH] media: ov9734: hold lock to check streaming state

[Bingbu Cao]

The lock in ov9734 is used to protect the streaming state and
serialize the stream on and off callbacks, it should be hold before
checking the streaming state in ov9734_set_stream().

Reported-by: Tomasz Figa <tfiga@chromium.org>
Reported-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Signed-off-by: Bingbu Cao <bingbu.cao@intel.com>
---
 drivers/media/i2c/ov9734.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/media/i2c/ov9734.c b/drivers/media/i2c/ov9734.c
index 4b9a2e9288e7..e212465489e8 100644
--- a/drivers/media/i2c/ov9734.c
+++ b/drivers/media/i2c/ov9734.c
@@ -637,10 +637,12 @@ static int ov9734_set_stream(struct v4l2_subdev *sd, int enable)
 	struct i2c_client *client = v4l2_get_subdevdata(sd);
 	int ret = 0;
 
-	if (ov9734->streaming == enable)
+	mutex_lock(&ov9734->mutex);
+	if (ov9734->streaming == enable) {
+		mutex_unlock(&ov9734->mutex);
 		return 0;
+	}
 
-	mutex_lock(&ov9734->mutex);
 	if (enable) {
 		ret = pm_runtime_get_sync(&client->dev);
 		if (ret < 0) {
-- 
2.7.4

Re: [PATCH] media: ov9734: hold lock to check streaming state

[Sergey Senozhatsky]

On (20/11/27 11:48), Bingbu Cao wrote:
> The lock in ov9734 is used to protect the streaming state and
> serialize the stream on and off callbacks, it should be hold before
> checking the streaming state in ov9734_set_stream().
> 
> Reported-by: Tomasz Figa <tfiga@chromium.org>
> Reported-by: Sergey Senozhatsky <senozhatsky@chromium.org>
> Signed-off-by: Bingbu Cao <bingbu.cao@intel.com>

Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>

	-ss