Do uvc_pm_get before we call uvc_queue_streamon. Although the current
code is correct, uvc_ioctl_streamon is always called after uvc_pm_get,
this change makes the code more resiliant to future changes.

This change also avoids calling streamoff, which is a rather ugly thing
to do.

Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_v4l2.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index 668a4e9d772c6d91f045ca75e2744b3a6c69da6b..862b4e34e5b629cf324479a9bb59ebe8784ccd5d 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -853,15 +853,16 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
 	if (handle->is_streaming)
 		return 0;
 
-	ret = uvc_queue_streamon(&stream->queue, type);
+	ret = uvc_pm_get(stream->dev);
 	if (ret)
 		return ret;
 
-	ret = uvc_pm_get(stream->dev);
+	ret = uvc_queue_streamon(&stream->queue, type);
 	if (ret) {
-		uvc_queue_streamoff(&stream->queue, type);
+		uvc_pm_put(stream->dev);
 		return ret;
 	}
+
 	handle->is_streaming = true;
 
 	return 0;

-- 
2.49.0.1266.g31b7d2e469-goog