On 7/3/2026 1:02 PM, 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,
s/later/latter
like Wayland compositors or tools like drm_info, enable the client cap on
such drivers they will be left without both color pipeline and the legacy
properties COLOR_ENCODING and COLOR_RANGE, effectively breaking YUV->RGB
conversion support.
Prevent that by only marking the cap supported if there are actually planes
with color pipelines.
Note: while the color pipeline replacement for the legacy properties is
still under review (1), we can assume that it will work as a drop-in
replacement.
This change will but a driver can also choose to export colorops like
programmable CTM_3x4 to achieve the same.
We should also perhaps document this somewhere that if a driver supports
LEGACY properties, it is imperative to implement some version of it with
the color pipeline line property.
That means any plane on any hardware currently supporting
the legacy properties will be able to offer a functionally equal color
pipeline and there will be no technical reason keep using the legacy
properties if both the driver and the client support the new API.
1:
https://lore.kernel.org/dri-devel/[email protected]/
Signed-off-by: Robert Mader <[email protected]>
---
Changes in v3:
- Move the new check behind the existing EINVAL ones
- Rebase on latest drm-misc-next
Changes in v2:
- Replace the driver feature with a simple check (suggested by Maarten
Lankhorst <[email protected]>)
Probably could use a Suggested-by: tag
Having said that, LGTM
Reviewed-by: Chaitanya Kumar Borah <[email protected]>
- Expand the commit message slightly and change the title
---
drivers/gpu/drm/drm_ioctl.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/drm_ioctl.c b/drivers/gpu/drm/drm_ioctl.c
index e2df4becce62..9039a39c4324 100644
--- a/drivers/gpu/drm/drm_ioctl.c
+++ b/drivers/gpu/drm/drm_ioctl.c
@@ -373,13 +373,25 @@ drm_setclientcap(struct drm_device *dev, void *data,
struct drm_file *file_priv)
return -EINVAL;
file_priv->supports_virtualized_cursor_plane = req->value;
break;
- case DRM_CLIENT_CAP_PLANE_COLOR_PIPELINE:
+ case DRM_CLIENT_CAP_PLANE_COLOR_PIPELINE: {
+ struct drm_plane *plane;
+ bool has_plane_with_color_pipeline = false;
+
if (!file_priv->atomic)
return -EINVAL;
if (req->value > 1)
return -EINVAL;
+ drm_for_each_plane(plane, dev) {
+ if (plane->color_pipeline_property) {
+ has_plane_with_color_pipeline = true;
+ break;
+ }
+ }
+ if (!has_plane_with_color_pipeline)
+ return -EOPNOTSUPP;
file_priv->plane_color_pipeline = req->value;
break;
+ }
default:
return -EINVAL;
}
