Re: [PATCH 09/10] uvcvideo: Properly report the inactive flag for inactive controls

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

Hi Hans,

Thanks for the patch.

On Sunday 25 March 2012 13:56:49 Hans de Goede wrote:
> Note the unused in this patch slave_ids addition to the mappings will get
> used in a follow up patch to generate control change events for the slave
> ctrls when their flags change due to the master control changing value.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/media/video/uvc/uvc_ctrl.c |   33 +++++++++++++++++++++++++++++++++
> drivers/media/video/uvc/uvcvideo.h |    4 ++++
>  2 files changed, 37 insertions(+)
> 
> diff --git a/drivers/media/video/uvc/uvc_ctrl.c
> b/drivers/media/video/uvc/uvc_ctrl.c index 742496f..91d9007 100644
> --- a/drivers/media/video/uvc/uvc_ctrl.c
> +++ b/drivers/media/video/uvc/uvc_ctrl.c

[snip]

> @@ -943,6 +961,8 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain
> *chain, struct uvc_control_mapping *mapping,
>  	struct v4l2_queryctrl *v4l2_ctrl)
>  {
> +	struct uvc_control_mapping *master_map;
> +	struct uvc_control *master_ctrl = NULL;
>  	struct uvc_menu_info *menu;
>  	unsigned int i;
>  	int ret = 0;
> @@ -958,6 +978,19 @@ static int __uvc_query_v4l2_ctrl(struct uvc_video_chain
> *chain, if (!(ctrl->info.flags & UVC_CTRL_FLAG_SET_CUR))
>  		v4l2_ctrl->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> 
> +	if (mapping->master_id)
> +		master_ctrl = uvc_find_control(chain, mapping->master_id,
> +					       &master_map);

As an optimization, do you think it would make sense to add a struct 
uvc_contro *master_ctrl field to struct uvc_control_mapping, and fill it in 
uvc_ctrl_init_ctrl() ? That would require a loop over the mappings at 
initialization time, but would get rid of the search operation at runtime. The 
master_ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR check would be performed at 
initialization time as well, and master_ctrl would be left NULL it the master 
control doesn't support the GET_CUR query.

> +	if (master_ctrl && (master_ctrl->info.flags & UVC_CTRL_FLAG_GET_CUR)) {
> +		s32 val;
> +		ret = __uvc_ctrl_get(chain, master_ctrl, master_map, &val);
> +		if (ret < 0)
> +			goto done;
> +
> +		if (val != mapping->master_manual)
> +				v4l2_ctrl->flags |= V4L2_CTRL_FLAG_INACTIVE;
> +	}
> +
>  	if (!ctrl->cached) {
>  		ret = uvc_ctrl_populate_cache(chain, ctrl);
>  		if (ret < 0)

-- 
Regards,

Laurent Pinchart