Re: [PATCH v5 1/5] media: uvcvideo: Only save async fh if success

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

On Mon, Dec 02, 2024 at 02:24:35PM +0000, Ricardo Ribalda wrote:
> Now we keep a reference to the active fh for any call to uvc_ctrl_set,
> regardless if it is an actual set or if it is a just a try or if the
> device refused the operation.
> 
> We should only keep the file handle if the device actually accepted
> applying the operation.
> 
> Cc: stable@vger.kernel.org
> Fixes: e5225c820c05 ("media: uvcvideo: Send a control event when a Control Change interrupt arrives")
> Suggested-by: Hans de Goede <hdegoede@redhat.com>
> Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>

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

> ---
>  drivers/media/usb/uvc/uvc_ctrl.c | 18 +++++++++++-------
>  1 file changed, 11 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> index 4fe26e82e3d1..9a80a7d8e73a 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -1811,7 +1811,10 @@ int uvc_ctrl_begin(struct uvc_video_chain *chain)
>  }
>  
>  static int uvc_ctrl_commit_entity(struct uvc_device *dev,
> -	struct uvc_entity *entity, int rollback, struct uvc_control **err_ctrl)
> +				  struct uvc_fh *handle,
> +				  struct uvc_entity *entity,
> +				  int rollback,
> +				  struct uvc_control **err_ctrl)
>  {
>  	struct uvc_control *ctrl;
>  	unsigned int i;
> @@ -1859,6 +1862,10 @@ static int uvc_ctrl_commit_entity(struct uvc_device *dev,
>  				*err_ctrl = ctrl;
>  			return ret;
>  		}
> +
> +		if (!rollback && handle &&
> +		    ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS)
> +			ctrl->handle = handle;
>  	}
>  
>  	return 0;
> @@ -1895,8 +1902,8 @@ int __uvc_ctrl_commit(struct uvc_fh *handle, int rollback,
>  
>  	/* Find the control. */
>  	list_for_each_entry(entity, &chain->entities, chain) {
> -		ret = uvc_ctrl_commit_entity(chain->dev, entity, rollback,
> -					     &err_ctrl);
> +		ret = uvc_ctrl_commit_entity(chain->dev, handle, entity,
> +					     rollback, &err_ctrl);
>  		if (ret < 0) {
>  			if (ctrls)
>  				ctrls->error_idx =
> @@ -2046,9 +2053,6 @@ int uvc_ctrl_set(struct uvc_fh *handle,
>  	mapping->set(mapping, value,
>  		uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
>  
> -	if (ctrl->info.flags & UVC_CTRL_FLAG_ASYNCHRONOUS)
> -		ctrl->handle = handle;
> -
>  	ctrl->dirty = 1;
>  	ctrl->modified = 1;
>  	return 0;
> @@ -2377,7 +2381,7 @@ int uvc_ctrl_restore_values(struct uvc_device *dev)
>  			ctrl->dirty = 1;
>  		}
>  
> -		ret = uvc_ctrl_commit_entity(dev, entity, 0, NULL);
> +		ret = uvc_ctrl_commit_entity(dev, NULL, entity, 0, NULL);
>  		if (ret < 0)
>  			return ret;
>  	}

-- 
Regards,

Laurent Pinchart