Re: [PATCH v2] media: uvcvideo: user entity get_cur in uvc_ctrl_set

[Ricardo Ribalda <ribalda@xxxxxxxxxxxx>]

Hi Yunke

Thanks for your patch

Another way to do it could be:

__uvc_ctrl_load_cur() {
if (loaded)
   return
   if ((ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR) {
       memset
       loaded = true;
       return
  }
...
}

int __uvc_ctrl_get() {
if ((ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR) == 0)
return -EACCES;
....
}

Then you could even simplify more the code in uvc_ctrl_set, and limit
the m handling of the loaded flag.


if ( (ctrl->info.size * 8) != mapping->size)
 ___uvc_ctrl_load_cur()


But It is probably just a matter of taste ;). It is up to you and
Laurent to pick what do you prefer.

Regards!


On Tue, 21 Jun 2022 at 08:15, Yunke Cao <yunkec@xxxxxxxxxx> 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@xxxxxxxxxx>
Reviewed-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
> ---
> Changelog since v1:
> -Factored out common logic into __uvc_ctrl_load_cur().
>
>  drivers/media/usb/uvc/uvc_ctrl.c | 62 ++++++++++++++++++--------------
>  1 file changed, 35 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_ctrl.c b/drivers/media/usb/uvc/uvc_ctrl.c
> index 0e78233fc8a0..e25177c95571 100644
> --- a/drivers/media/usb/uvc/uvc_ctrl.c
> +++ b/drivers/media/usb/uvc/uvc_ctrl.c
> @@ -963,36 +963,48 @@ static s32 __uvc_ctrl_get_value(struct uvc_control_mapping *mapping,
>         return value;
>  }
>
> -static int __uvc_ctrl_get(struct uvc_video_chain *chain,
> -       struct uvc_control *ctrl, struct uvc_control_mapping *mapping,
> -       s32 *value)
> +static int __uvc_ctrl_load_cur(struct uvc_video_chain *chain,
> +                              struct uvc_control *ctrl)
>  {
> -       int ret;
> +       int ret = 0;
nit :  why do you init to 0?
>
>         if ((ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR) == 0)
>                 return -EACCES;
>
> -       if (!ctrl->loaded) {
> -               if (ctrl->entity->get_cur) {
nit: is this spaced properly?
> -                       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 (ctrl->loaded)
> +               return 0;
>
> -               ctrl->loaded = 1;
> +       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;
> +
> +       ctrl->loaded = 1;
> +
> +       return ret;
> +}
> +
> +static int __uvc_ctrl_get(struct uvc_video_chain *chain,
> +       struct uvc_control *ctrl, struct uvc_control_mapping *mapping,
> +       s32 *value)
> +{
nit: Is the alignment correct here?
> +       int ret = __uvc_ctrl_load_cur(chain, ctrl);
> +
> +       if (ret < 0)
> +               return ret;
> +
>         *value = __uvc_ctrl_get_value(mapping,
>                                 uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT));
>
> @@ -1788,11 +1800,7 @@ int uvc_ctrl_set(struct uvc_fh *handle,
>                         memset(uvc_ctrl_data(ctrl, UVC_CTRL_DATA_CURRENT),
>                                 0, 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);
> +                       ret = __uvc_ctrl_load_cur(chain, ctrl);
>                         if (ret < 0)
>                                 return ret;
>                 }
> --
> 2.37.0.rc0.104.g0611611a94-goog



-- 
Ricardo Ribalda