[PATCH v5 1/2] media: uvcvideo: Refactor streamon/streamoff

From: Ricardo Ribalda
Date: Tue Dec 06 2022 - 09:07:36 EST


Add a new variable to handle the streaming state and handle the
streamoff errors, that were not handled before.

Suggested-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Reviewed-by: Max Staudt <mstaudt@xxxxxxxxxxxx>
Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
---
drivers/media/usb/uvc/uvc_v4l2.c | 19 ++++++++++++++++---
drivers/media/usb/uvc/uvcvideo.h | 1 +
2 files changed, 17 insertions(+), 3 deletions(-)

diff --git a/drivers/media/usb/uvc/uvc_v4l2.c b/drivers/media/usb/uvc/uvc_v4l2.c
index f4d4c33b6dfb..1389a87b8ae1 100644
--- a/drivers/media/usb/uvc/uvc_v4l2.c
+++ b/drivers/media/usb/uvc/uvc_v4l2.c
@@ -840,13 +840,19 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
{
struct uvc_fh *handle = fh;
struct uvc_streaming *stream = handle->stream;
- int ret;
+ int ret = -EBUSY;

if (!uvc_has_privileges(handle))
return -EBUSY;

mutex_lock(&stream->mutex);
+
+ if (handle->is_streaming)
+ goto unlock;
ret = uvc_queue_streamon(&stream->queue, type);
+ handle->is_streaming = !ret;
+
+unlock:
mutex_unlock(&stream->mutex);

return ret;
@@ -857,15 +863,22 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
{
struct uvc_fh *handle = fh;
struct uvc_streaming *stream = handle->stream;
+ int ret = 0;

if (!uvc_has_privileges(handle))
return -EBUSY;

mutex_lock(&stream->mutex);
- uvc_queue_streamoff(&stream->queue, type);
+
+ if (!handle->is_streaming)
+ goto unlock;
+ ret = uvc_queue_streamoff(&stream->queue, type);
+ handle->is_streaming = !!ret;
+
+unlock:
mutex_unlock(&stream->mutex);

- return 0;
+ return ret;
}

static int uvc_ioctl_enum_input(struct file *file, void *fh,
diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
index df93db259312..0d9f335053b8 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -584,6 +584,7 @@ struct uvc_fh {
struct uvc_video_chain *chain;
struct uvc_streaming *stream;
enum uvc_handle_state state;
+ bool is_streaming;
};

struct uvc_driver {

--
2.39.0.rc0.267.gcb52ba06e7-goog-b4-0.11.0-dev-696ae