Hi,
On Wed, 2018-07-04 at 17:38 +0200, Hans Verkuil wrote:
> If a driver needs to find/inspect the controls set in a request then
> it can use these functions.
>
> E.g. to check if a required control is set in a request use this in the
> req_validate() implementation:
>
> int res = -EINVAL;
>
> hdl = v4l2_ctrl_request_hdl_find(req, parent_hdl);
> if (hdl) {
> if (v4l2_ctrl_request_hdl_ctrl_find(hdl, ctrl_id))
> res = 0;
> v4l2_ctrl_request_hdl_put(hdl);
> }
> return res;
Thanks again for pulling this off, that's definitely what I neeeded!
I was able to test the patch and get it to work with sunxi-cedrus, with
one modification highlighted below.
Note that for my use case, I need to have access to the driver's private
data (context) to get the parent hdl. I'm iterating over request objects
and getting the context from a buffer object (checked via
vb2_request_object_is_buffer), a bit like it's done in
vb2_m2m_request_queue.
> Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx>
> ---
> Paul, please test this. This should be what you need.
>
> Regards,
>
> Hans
> ---
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
> index 3ff17c87b3c8..03fd140736fd 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
> @@ -2976,6 +2976,31 @@ static const struct media_request_object_ops req_ops = {
> .release = v4l2_ctrl_request_release,
> };
>
> +struct v4l2_ctrl_handler *v4l2_ctrl_request_hdl_find(struct media_request *req,
> + struct v4l2_ctrl_handler *parent)
> +{
> + struct media_request_object *obj;
> +
> + if (WARN_ON(req->state != MEDIA_REQUEST_STATE_VALIDATING &&
> + req->state != MEDIA_REQUEST_STATE_QUEUED))
> + return NULL;
> +
> + obj = media_request_object_find(req, &req_ops, parent);
> + if (obj)
> + return container_of(obj, struct v4l2_ctrl_handler, req_obj);
> + return NULL;
> +}
> +EXPORT_SYMBOL_GPL(v4l2_ctrl_request_hdl_find);
> +
> +struct v4l2_ctrl *
> +v4l2_ctrl_request_hdl_ctrl_find(struct v4l2_ctrl_handler *hdl, u32 id)
> +{
> + struct v4l2_ctrl_ref *ref = find_ref_lock(hdl, id);
> +
> + return (ref && ref->req == ref) ? ref : NULL;
When req && ref->req == ref, ref->ctrl should be returned instead of
ref.
Cheers,
Paul
--
Paul Kocialkowski, Bootlin (formerly Free Electrons)
Embedded Linux and kernel engineering
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