Re: [PATCH] media: uvcvideo: Fix custom control mapping probing

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

On Mon, Jul 22, 2024 at 01:41:14PM +0200, Ricardo Ribalda wrote:
> On Mon, 22 Jul 2024 at 13:39, Laurent Pinchart wrote:
> > On Mon, Jul 22, 2024 at 07:59:43AM +0000, Ricardo Ribalda wrote:
> > > Custom control mapping introduced a bug, where the filter function was
> > > applied to every single control.
> > >
> > > Fix it so it is only applied to the matching controls.
> > >
> > > Reported-by: Paul Menzen <pmenzel@molgen.mpg.de>
> > > Closes: https://lore.kernel.org/linux-media/518cd6b4-68a8-4895-b8fc-97d4dae1ddc4@molgen.mpg.de/T/#t
> > > Cc: stable@vger.kernel.org
> > > Fixes: 8f4362a8d42b ("media: uvcvideo: Allow custom control mapping")
> > > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> > > ---
> > > Paul, could you check if this fixes your issue, thanks!
> > > ---
> > >  drivers/media/usb/uvc/uvc_ctrl.c | 8 +++++---
> > >  1 file changed, 5 insertions(+), 3 deletions(-)
> > >
> > > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> > > index 0136df5732ba..06fede57bf36 100644
> > > --- a/drivers/media/usb/uvc/uvc_ctrl.c
> > > +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> > > @@ -2680,6 +2680,10 @@ static void uvc_ctrl_init_ctrl(struct uvc_video_chain *chain,
> > >       for (i = 0; i < ARRAY_SIZE(uvc_ctrl_mappings); ++i) {
> > >               const struct uvc_control_mapping *mapping = &uvc_ctrl_mappings[i];
> > >
> > > +             if (!(uvc_entity_match_guid(ctrl->entity, mapping->entity) &&
> > > +                 ctrl->info.selector == mapping->selector))
> > > +                     continue;
> >
> > I have a slight preference for
> >
> >                 if (!uvc_entity_match_guid(ctrl->entity, mapping->entity) ||
> >                     ctrl->info.selector != mapping->selector)
> >                         continue;
> >
> > If that's fine with you, I can handle that when applying the patch.
> 
> That looks also good. I can send a v2 if you prefer. I would also add
> the error messages to the commit message.
> Let me know what do you prefer, I have time today

If you can send a v2 with an improved commit message that would be nice.
I'll apply it right away.

> > This change means that the entity and selector test will use the
> > original mapping, not the mapping returned by the filtering function. I
> > think that's fine, both mappings should have the same entity and
> > selector, only the menu mask is meant to change.
> >
> > Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
> >
> > > +
> > >               /* Let the device provide a custom mapping. */
> > >               if (mapping->filter_mapping) {
> > >                       mapping = mapping->filter_mapping(chain, ctrl);
> > > @@ -2687,9 +2691,7 @@ static void uvc_ctrl_init_ctrl(struct uvc_video_chain *chain,
> > >                               continue;
> > >               }
> > >
> > > -             if (uvc_entity_match_guid(ctrl->entity, mapping->entity) &&
> > > -                 ctrl->info.selector == mapping->selector)
> > > -                     __uvc_ctrl_add_mapping(chain, ctrl, mapping);
> > > +             __uvc_ctrl_add_mapping(chain, ctrl, mapping);
> > >       }
> > >  }
> > >
> > >
> > > ---
> > > base-commit: 68a72104cbcf38ad16500216e213fa4eb21c4be2
> > > change-id: 20240722-fix-filter-mapping-18477dc69048

-- 
Regards,

Laurent Pinchart