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

Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
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;

-- 
2.49.0.1151.ga128411c76-goog

On 22/05/2025 19:58, Ricardo Ribalda wrote:
> Do uvc_pm_get before we call uvc_queue_streamon. Although the current
> code is correct, uvc_ioctl_streamon is allways called after uvc_pm_get,

allways -> always

> this change makes the code more resiliant to future changes.

I would add that this change also avoids calling streamoff, which is
a rather ugly thing to do.

> 
> Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>

Reviewed-by: Hans Verkuil <hverkuil@xs4all.nl>

Regards,

	Hans

> ---
>  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;
>

Hi Ricardo,

Thank you for the patch.

On Thu, May 22, 2025 at 05:58:46PM +0000, Ricardo Ribalda wrote:
> Do uvc_pm_get before we call uvc_queue_streamon. Although the current
> code is correct, uvc_ioctl_streamon is allways called after uvc_pm_get,
> this change makes the code more resiliant to future changes.
> 
> Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
>  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;

-- 
Regards,

Laurent Pinchart

Hi Laurent

Thanks for your review

On Thu, 22 May 2025 at 23:40, Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
>
> Hi Ricardo,
>
> Thank you for the patch.
>
> On Thu, May 22, 2025 at 05:58:46PM +0000, Ricardo Ribalda wrote:
> > Do uvc_pm_get before we call uvc_queue_streamon. Although the current
> > code is correct, uvc_ioctl_streamon is allways called after uvc_pm_get,
> > this change makes the code more resiliant to future changes.
> >
> > Suggested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
>
> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

Unless you say otherwise I will copy this Review-by to the original
series where this patch belongs to.
https://patchwork.linuxtv.org/project/linux-media/list/?series=15227

Thanks!


>
> > ---
> >  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;
>
> --
> Regards,
>
> Laurent Pinchart



-- 
Ricardo Ribalda