Re: [PATCH v5 5/5] media: uvcvideo: Flush the control cache when we get an event

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 2-Dec-24 3:24 PM, Ricardo Ribalda wrote:
> Asynchronous controls trigger an event when they have completed their
> operation.
> 
> This can make that the control cached value does not match the value in
> the device.
> 
> Let's flush the cache to be on the safe side.
> 
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> ---
>  drivers/media/usb/uvc/uvc_ctrl.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> index e90bf2aeb5e4..75d534072f50 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -1672,6 +1672,9 @@ bool uvc_ctrl_status_event_async(struct urb *urb, struct uvc_video_chain *chain,
>  	struct uvc_device *dev = chain->dev;
>  	struct uvc_ctrl_work *w = &dev->async_ctrl;
>  
> +	/* Flush the control cache, the data might have changed. */
> +	ctrl->loaded = 0;
> +
>  	if (list_empty(&ctrl->info.mappings))
>  		return false;
>  
>


Thank you for the patch.

I'm not familiar enough with UVC yet to really have an opinion on this one,
so I'll defer reviewing this one to Laurent.

Regards,

Hans