diff mbox series

[v4,1/2] media: uvcvideo: Refactor streamon/streamoff

Message ID 20220920-resend-powersave-v4-1-47484ae40761@chromium.org
State New
Headers
Series media: uvcvideo: Implement granular power management |

Commit Message

Ricardo Ribalda Dec. 2, 2022, 5:19 p.m. UTC 
  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@ideasonboard.com>
Reviewed-by: Max Staudt <mstaudt@chromium.org>
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
---
 drivers/media/usb/uvc/uvc_v4l2.c | 19 ++++++++++++++++---
 drivers/media/usb/uvc/uvcvideo.h |  1 +
 2 files changed, 17 insertions(+), 3 deletions(-)

Comments

Sergey Senozhatsky Dec. 6, 2022, 2:12 a.m. UTC | #1 
On (22/12/02 18:19), Ricardo Ribalda wrote:
> @@ -840,13 +840,19 @@ static int uvc_ioctl_streamon(struct file *file, void *fh,
[..]
> +	handle->is_streaming = !ret;


> @@ -857,15 +863,22 @@ static int uvc_ioctl_streamoff(struct file *file, void *fh,
[..]
> +	handle->is_streaming = !!ret;

Had uvc_ioctl_streamABC() be 3 functions we would have seen

	handle->is_streaming = !!!ret;

:)


[..]

A nit:

>  struct uvc_fh {
>  	struct v4l2_fh vfh;
> +	bool is_streaming;

That's a lot of padding.

>  	struct uvc_video_chain *chain;
>  	struct uvc_streaming *stream;
>  	enum uvc_handle_state state;

I guess is_streaming better be next to enum uvc_handle_state, in which
case is_streaming should not change sizeof(uvc_fh) (at least so on
64-bit).
diff mbox series

Patch

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..45310f55475f 100644
--- a/drivers/media/usb/uvc/uvcvideo.h
+++ b/drivers/media/usb/uvc/uvcvideo.h
@@ -581,6 +581,7 @@  enum uvc_handle_state {
 
 struct uvc_fh {
 	struct v4l2_fh vfh;
+	bool is_streaming;
 	struct uvc_video_chain *chain;
 	struct uvc_streaming *stream;
 	enum uvc_handle_state state;