Hi Ricardo,
Thank you for the patch.
On Fri, Mar 12, 2021 at 01:48:26PM +0100, Ricardo Ribalda wrote:
> If an error is found when validating the list of controls passed with
> VIDIOC_G_EXT_CTRLS, then error_idx shall be set to ctrls->count to
> indicate
> to userspace that no actual hardware was touched.
>
> It would have been much nicer of course if error_idx could point to the
> control index that failed the validation, but sadly that's not how the
> API was designed.
>
> Fixes v4l2-compliance:
> Control ioctls (Input 0):
> fail: v4l2-test-controls.cpp(645): invalid error index write
> only control
> test VIDIOC_G/S/TRY_EXT_CTRLS: FAIL
>
> Signed-off-by: Ricardo Ribalda <riba...@chromium.org>
> Reviewed-by: Hans Verkuil <hverkuil-ci...@xs4all.nl>
Still pending discussions in v2.
> ---
> drivers/media/usb/uvc/uvc_v4l2.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/media/usb/uvc/uvc_v4l2.c
> b/drivers/media/usb/uvc/uvc_v4l2.c
> index 157310c0ca87..36eb48622d48 100644
> --- a/drivers/media/usb/uvc/uvc_v4l2.c
> +++ b/drivers/media/usb/uvc/uvc_v4l2.c
> @@ -1073,7 +1073,8 @@ static int uvc_ioctl_g_ext_ctrls(struct file *file,
> void *fh,
> ret = uvc_ctrl_get(chain, ctrl);
> if (ret < 0) {
> uvc_ctrl_rollback(handle);
> - ctrls->error_idx = i;
> + ctrls->error_idx = (ret == -EACCES) ?
> + ctrls->count : i;
> return ret;
> }
> }
--
Regards,
Laurent Pinchart
