[PATCH] drm: document userspace expectations around the Colorspace connector property

[Xaver Hugl]

Signed-off-by: Xaver Hugl <xaver.hugl at kde.org>
---
 drivers/gpu/drm/drm_connector.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index b0516505f7ae..01e13984629b 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -2158,6 +2158,14 @@ EXPORT_SYMBOL(drm_mode_create_aspect_ratio_property);
  *     one supported. Sink supported colorspaces should be retrieved by
  *     userspace from EDID and driver will not explicitly expose them.
  *
+ *     As userspace can't currently know whether or not the output is using
+ *     RGB or YCC signalling, the driver must translate properties to their
+ *     relevant RGB or YCC counterparts, depending on the actually used
+ *     signalling. Property values that are only valid for either YCC or RGB
+ *     and have no equivalent for the other signalling type must not be
+ *     exposed as supported, unless the driver can guarantee it never uses
+ *     the signalling that doesn't match the property.
+ *
  *     Basically the expectation from userspace is:
  *      - Set up CRTC DEGAMMA/CTM/GAMMA to convert to some sink
  *        colorspace
-- 
2.43.0