On 15/01/2021 12:53, Sebastian Fricke wrote:
> Hello,
>
> I believe you are the creator of v4l2-compliance, right? My hope is that you might be able to lead me in the right direction.
> I am currently finishing up a sensor driver that I ported from a downstream kernel. And I try to clear up the last compliance error:
>
> ```
> info: checking control event 'User Controls' (0x00980001)
> VIDIOC_SUBSCRIBE_EVENT returned -1 (Inappropriate ioctl for device)
This returns ENOTTY, which is weird...
> fail: v4l2-test-controls.cpp(818): subscribe event for control 'User Controls' failed
> test VIDIOC_(UN)SUBSCRIBE_EVENT/DQEVENT: FAIL
> ```
>
> I notice that it calls a normal v4l2 ioctl on my subdevice. I implemented the event handling just like I was able to find in other devices like:
> imx219, imx355, ov2640 by adding:
>
> ```
> #include <media/v4l2-event.h>
> ...
> sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE |
> V4L2_SUBDEV_FL_HAS_EVENTS;
> ...
> static const struct v4l2_subdev_core_ops ov13850_core_ops = {
> ...
> .subscribe_event = v4l2_ctrl_subdev_subscribe_event,
> .unsubscribe_event = v4l2_event_subdev_unsubscribe
> ...
> ```
...since this looks exactly as it should be.
>
> Am I supposed to correct that error, or asked in another way is it actually an error when a subdevice doesn't implement VIDIOC_SUBSCRIBE_EVENT?
Yes, it is an error if subscribe_event isn't implemented, but you DO have controls in your driver.
Are you compiling v4l2-compliance from the git repo? You shouldn't use the version packages by distros since that is typically much too old.
I can't give support either if you are using an old version.
> Additionally, I noticed that the compliance check doesn't look at my VIDIOC_SUBDEV_G_SELECTION implementation but instead searches for any implementation of the VIDIOC_G_SELECTION ioctl.
It shouldn't, at least v4l2-test-subdevs.cpp only uses VIDIOC_SUBDEV_G_SELECTION.
Regards,
Hans
>
> I invoked the compliance test with:
>
> v4l2-compliance -u /dev/v4l-subdev3 -v -T
>
> My current code can be located here: https://github.com/initBasti/Linux_kernel_media_tree_fork/blob/fix_subscribe_event_user_controls/drivers/media/i2c/ov13850.c
>
> Greetings and thanks in advance,
> Sebastian
>
