Re: [PATCH v1 1/4] drm: Guard DRM_CLIENT_CAP_PLANE_COLOR_PIPELINE behind driver feature

[Robert Mader <robert.mader@collabora.com>]

On 30.06.26 10:42, Robert Mader wrote:
> The client cap is currently advertised unconditionally, even for drivers that do
> not support plane color pipelines. If clients supporting the later, like Wayland
> compositors and drm_info, enable the client cap on sich drivers they will be
> left without both color pipeline and the legacy properties COLOR_ENCODING and
> COLOR_RANGE, effectively breaking YUV->RGB conversion support.
>
> Add a new driver feature and guard the client cap behind it, allowing
> plane color pipeline and legacy YUV->RGB support to co-exist.
>
> Signed-off-by: Robert Mader <robert.mader@collabora.com>
> ---
>   drivers/gpu/drm/drm_ioctl.c | 2 ++
>   include/drm/drm_drv.h       | 6 ++++++
>   2 files changed, 8 insertions(+)
>
> diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
> index ff193155129e..96fda92e31b9 100644
> --- a/drivers/gpu/drm/drm_ioctl.c
> +++ b/drivers/gpu/drm/drm_ioctl.c
> @@ -374,6 +374,8 @@ drm_setclientcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
>   		file_priv->supports_virtualized_cursor_plane = req->value;
>   		break;
>   	case DRM_CLIENT_CAP_PLANE_COLOR_PIPELINE:
> +		if (!drm_core_check_feature(dev, DRIVER_PLANE_COLOR_PIPELINE))
> +			return -EOPNOTSUPP;
>   		if (!file_priv->atomic)
>   			return -EINVAL;
>   		if (req->value > 1)
> diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
> index e09559495c5b..108ddd2c8d30 100644
> --- a/include/drm/drm_drv.h
> +++ b/include/drm/drm_drv.h
> @@ -116,6 +116,12 @@ enum drm_driver_feature {
>   	 * the cursor planes to work correctly).
>   	 */
>   	DRIVER_CURSOR_HOTSPOT           = BIT(9),
> +	/**
> +	 * @DRIVER_PLANE_COLOR_PIPELINE:
> +	 *
> +	 * Driver supports PLANE_COLOR_PIPELINE.

Sorry, forgot to append a change here. This would be

* Driver supports plane color pipelines.

in v2 (unless somebody requests another change).

> +	 */
> +	DRIVER_PLANE_COLOR_PIPELINE	= BIT(10),
>   
>   	/* IMPORTANT: Below are all the legacy flags, add new ones above. */
>   

-- 
Robert Mader
Consultant Software Developer

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