[v1] media: uvcvideo: user entity get_cur in uvc_ctrl_set

  Entity controls should get_cur using an entity-defined function
instead of via a query. Fix this in uvc_ctrl_set.

Fixes: 65900c581d01 ("media: uvcvideo: Allow entity-defined get_info and get_cur")
Signed-off-by: Yunke Cao <yunkec@google.com>
---
 drivers/media/usb/uvc/uvc_ctrl.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)
  

Hi Yunke,

Thank you for the patch.

On Tue, Jun 21, 2022 at 01:35:06PM +0900, Yunke Cao wrote:
> Entity controls should get_cur using an entity-defined function
> instead of via a query. Fix this in uvc_ctrl_set.
> 
> Fixes: 65900c581d01 ("media: uvcvideo: Allow entity-defined get_info and get_cur")
> Signed-off-by: Yunke Cao <yunkec@google.com>
> ---
>  drivers/media/usb/uvc/uvc_ctrl.c | 10 ++++++++--
>  1 file changed, 8 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> index 0e78233fc8a0..54c047019313 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -1787,15 +1787,21 @@ int uvc_ctrl_set(struct uvc_fh *handle,
>  		if ((ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR) == 0) {
>  			memset(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
>  				0, ctrl->info.size);
> +		} else if (ctrl->entity->get_cur) {
> +			ret = ctrl->entity->get_cur(chain->dev,
> +				ctrl->entity,
> +				ctrl->info.selector,
> +				uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
> +				ctrl->info.size);
>  		} else {
>  			ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR,
>  				ctrl->entity->id, chain->dev->intfnum,
>  				ctrl->info.selector,
>  				uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
>  				ctrl->info.size);
> -			if (ret < 0)
> -				return ret;
>  		}
> +		if (ret < 0)
> +			return ret;

ret may be used uninitialized here.

>  
>  		ctrl->loaded = 1;

There's very similar code in __uvc_ctrl_get(), could it be factored out,
maybe into a __uvc_ctrl_get_cur() function ?

>  	}
  

Hi Laurent,

Thanks for the review.

On Tue, Jun 21, 2022 at 2:51 PM Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
>
> Hi Yunke,
>
> Thank you for the patch.
>
> On Tue, Jun 21, 2022 at 01:35:06PM +0900, Yunke Cao wrote:
> > Entity controls should get_cur using an entity-defined function
> > instead of via a query. Fix this in uvc_ctrl_set.
> >
> > Fixes: 65900c581d01 ("media: uvcvideo: Allow entity-defined get_info and get_cur")
> > Signed-off-by: Yunke Cao <yunkec@google.com>
> > ---
> >  drivers/media/usb/uvc/uvc_ctrl.c | 10 ++++++++--
> >  1 file changed, 8 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> > index 0e78233fc8a0..54c047019313 100644
> > --- a/drivers/media/usb/uvc/uvc_ctrl.c
> > +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> > @@ -1787,15 +1787,21 @@ int uvc_ctrl_set(struct uvc_fh *handle,
> >               if ((ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR) == 0) {
> >                       memset(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
> >                               0, ctrl->info.size);
> > +             } else if (ctrl->entity->get_cur) {
> > +                     ret = ctrl->entity->get_cur(chain->dev,
> > +                             ctrl->entity,
> > +                             ctrl->info.selector,
> > +                             uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
> > +                             ctrl->info.size);
> >               } else {
> >                       ret = uvc_query_ctrl(chain->dev, UVC_GET_CUR,
> >                               ctrl->entity->id, chain->dev->intfnum,
> >                               ctrl->info.selector,
> >                               uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
> >                               ctrl->info.size);
> > -                     if (ret < 0)
> > -                             return ret;
> >               }
> > +             if (ret < 0)
> > +                     return ret;
>
> ret may be used uninitialized here.
>
> >
> >               ctrl->loaded = 1;
>
> There's very similar code in __uvc_ctrl_get(), could it be factored out,
> maybe into a __uvc_ctrl_get_cur() function ?
>

Sounds good! I'm sending out v2.

Changelog since v1:
-Factored out common logic into __uvc_ctrl_load_cur(). (I called it
"load_cur" because I feel it's a bit more accurate)

Best,
Yunke

> >       }
>
> --
> Regards,
>
> Laurent Pinchart