Hi Ricardo,
Thank you for the patch.
On Fri, Dec 02, 2022 at 06:08:17PM +0100, Ricardo Ribalda wrote:
> Devices with Metadata output (like uvc), create two video devices, one
> for the data itself and another one for the metadata.
>
> Add a "Meta: " to the beginning of the device name, as suggested by Mauro,
> to avoid having multiple devices with the same name.
>
> Fixes v4l2-compliance:
> Media Controller ioctls:
> fail: v4l2-test-media.cpp(205): v2_entity_names_set.find(key) != v2_entity_names_set.end()
> test MEDIA_IOC_G_TOPOLOGY: FAIL
> fail: v4l2-test-media.cpp(394): num_data_links != num_links
> test MEDIA_IOC_ENUM_ENTITIES/LINKS: FAIL
>
> Suggested-by: Mauro Carvalho Chehab <mchehab+huawei@xxxxxxxxxx>
> Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
> ---
> drivers/media/v4l2-core/v4l2-dev.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> diff --git a/drivers/media/v4l2-core/v4l2-dev.c b/drivers/media/v4l2-core/v4l2-dev.c
> index 397d553177fa..5c2c9ebb6b96 100644
> --- a/drivers/media/v4l2-core/v4l2-dev.c
> +++ b/drivers/media/v4l2-core/v4l2-dev.c
> @@ -901,6 +901,15 @@ int __video_register_device(struct video_device *vdev,
> if (WARN_ON(type != VFL_TYPE_SUBDEV && !vdev->device_caps))
> return -EINVAL;
>
> + /* Add Meta: to metadata device names */
> + if (vdev->device_caps &
> + (V4L2_CAP_META_CAPTURE | V4L2_CAP_META_OUTPUT)) {
> + char aux[sizeof(vdev->name)];
> +
> + snprintf(aux, sizeof(aux), "Meta: %s", vdev->name);
This will break userspace I'm afraid. libcamera looks up video devices
by entity names for multiple platforms. I wouldn't be surprised if other
userspace applications did something similar.
> + strscpy(vdev->name, aux, sizeof(aux));
> + }
> +
> /* v4l2_fh support */
> spin_lock_init(&vdev->fh_lock);
> INIT_LIST_HEAD(&vdev->fh_list);
>
--
Regards,
Laurent Pinchart
