On 02/20/18 05:44, Alexandre Courbot wrote:
> Only standard controls can be successfully cloned: handler_new_ref, used
> by v4l2_ctrl_request_clone(), forcibly calls v4l2_ctrl_new_std() which
> fails to find custom controls names, and we eventually hit the condition
> that name == NULL in v4l2_ctrl_new().
Hmm, the core reason is that handler_new_ref tries to automatically create
a new control class if it didn't exist yet. Which is OK for standard control
classes but not for non-standard control classes such as is used in vivid.
I will have to think about this.
Regards,
Hans
>
> This prevents us from using non-standard controls with requests, but
> that is enough for testing purposes.
>
> Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxxxx>
> ---
> drivers/media/v4l2-core/v4l2-ctrls.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
> index 166647817efb..7a81aa5959c3 100644
> --- a/drivers/media/v4l2-core/v4l2-ctrls.c
> +++ b/drivers/media/v4l2-core/v4l2-ctrls.c
> @@ -2772,6 +2772,11 @@ int v4l2_ctrl_request_clone(struct v4l2_ctrl_handler *hdl,
> if (filter && !filter(ctrl))
> continue;
> err = handler_new_ref(hdl, ctrl, &new_ref, false);
> + if (err) {
> + printk("%s: handler_new_ref on control %x (%s) returned %d\n", __func__, ctrl->id, ctrl->name, err);
> + err = 0;
> + continue;
> + }
> if (err)
> break;
> if (from->is_request)
>
