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References: <20220617103645.71560-1-ribalda@chromium.org> <20220617103645.71560-4-ribalda@chromium.org>
 <YqyGfFK3UXhrBLwK@pendragon.ideasonboard.com>
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From:   Ricardo Ribalda <ribalda@chromium.org>
Date:   Fri, 17 Jun 2022 15:55:52 +0200
Message-ID: <CANiDSCvOD08QD-2DKmrr2nNF+uC685tcnjBbMg0gGQc5ktR7qg@mail.gmail.com>
Subject: Re: [PATCH v7 3/8] media: uvcvideo: Support minimum for V4L2_CTRL_TYPE_MENU
To:     Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc:     Mauro Carvalho Chehab <mchehab@kernel.org>,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        tfiga@chromium.org, senozhatsky@chromium.org, yunkec@google.com
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Hi Laurent

On Fri, 17 Jun 2022 at 15:50, Laurent Pinchart
<laurent.pinchart@ideasonboard.com> wrote:
>
> Hi Ricardo,
>
> Thank you for the patch.
>
> On Fri, Jun 17, 2022 at 12:36:40PM +0200, Ricardo Ribalda wrote:
> > Currently all mappings of type V4L2_CTRL_TYPE_MENU, have a minimum of 0,
> > but there are some controls (limited powerline), that start with a value
> > different than 0.
> >
> > Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
> > ---
> >  drivers/media/usb/uvc/uvc_ctrl.c | 5 +++--
> >  drivers/media/usb/uvc/uvcvideo.h | 1 +
> >  2 files changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> > index 092decfdaa62..3b20b23abd1e 100644
> > --- a/drivers/media/usb/uvc/uvc_ctrl.c
> > +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> > @@ -1144,7 +1144,7 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain *chain,
> >
> >       switch (mapping->v4l2_type) {
> >       case V4L2_CTRL_TYPE_MENU:
> > -             v4l2_ctrl->minimum = 0;
> > +             v4l2_ctrl->minimum = mapping->menu_min;
> >               v4l2_ctrl->maximum = mapping->menu_count - 1;
> >               v4l2_ctrl->step = 1;
> >
> > @@ -1264,7 +1264,8 @@ int uvc_query_v4l2_menu(struct uvc_video_chain *chain,
> >               goto done;
> >       }
> >
> > -     if (query_menu->index >= mapping->menu_count) {
> > +     if (query_menu->index < mapping->menu_min ||
> > +         query_menu->index >= mapping->menu_count) {
> >               ret = -EINVAL;
> >               goto done;
> >       }
> > diff --git a/drivers/media/usb/uvc/uvcvideo.h b/drivers/media/usb/uvc/uvcvideo.h
> > index fff5c5c99a3d..6ceb7f7b964d 100644
> > --- a/drivers/media/usb/uvc/uvcvideo.h
> > +++ b/drivers/media/usb/uvc/uvcvideo.h
> > @@ -254,6 +254,7 @@ struct uvc_control_mapping {
> >       u32 data_type;
> >
> >       const struct uvc_menu_info *menu_info;
> > +     u32 menu_min;
> >       u32 menu_count;
>
> That's a bit of a stop-gap measure, could we turn it into a bitmask
> instead ?
Unfortunately that is uAPI :(

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/include/uapi/linux/v4l2-controls.h#n101

We have to keep the control type and its values.

Regards!
>
> >
> >       u32 master_id;
>
> --
> Regards,
>
> Laurent Pinchart


-- 
Ricardo Ribalda