Messages in this thread Patch in this message | | | Date | Tue, 27 Dec 2022 16:49:07 +0200 | From | Laurent Pinchart <> | Subject | Re: [PATCH v5 1/2] media: uvcvideo: Refactor streamon/streamoff |
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Hi Ricardo,
Thank you for the patch.
On Tue, Dec 06, 2022 at 03:06:55PM +0100, Ricardo Ribalda wrote: > 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(-) > > 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;
This isn't needed, uvc_queue_streamon() calls vb2_streamon(), which returns an error if the queue is already streaming.
> ret = uvc_queue_streamon(&stream->queue, type); > + handle->is_streaming = !ret;
You can just turn this into
if (!ret) handle->is_streaming = true;
and drop all other changes to this function.
> + > +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;
More than unneeded, this is wrong. Calling VIDIOC_STREAMOFF on a queue that is not streaming is a valid use case, it's the only way to release buffers that have been queued to the device. vb2_core_streamoff() handles this correctly. You should drop this check.
> + ret = uvc_queue_streamoff(&stream->queue, type); > + handle->is_streaming = !!ret;
And turn this into
if (!ret) handle->is_streaming = false;
and drop all other changes to this function.
> + > +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 { >
-- Regards,
Laurent Pinchart
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