[v2] drm: Document requirements for driver-specific KMS props in new drivers

Commit Message

Sebastian Wick April 10, 2024, 12:20 p.m. UTC

When extending support for a driver-specific KMS property to additional
drivers, we should apply all the requirements for new properties and
make sure the semantics are the same and documented.

v2: devs of the driver which introduced property shall help and ack

Signed-off-by: Sebastian Wick <[e-mail]>
Acked-by: Maxime Ripard <[e-mail]>
Acked-by: Daniel Vetter <[e-mail]>
---
 Documentation/gpu/drm-kms.rst | 7 +++++++
 1 file changed, 7 insertions(+)

Comments

Maxime Ripard April 15, 2024, 8:13 a.m. UTC | #1

On Wed, 10 Apr 2024 14:20:06 +0200, Sebastian Wick wrote:
> When extending support for a driver-specific KMS property to additional
> drivers, we should apply all the requirements for new properties and
> make sure the semantics are the same and documented.
> 
> v2: devs of the driver which introduced property shall help and ack
> 
> 
> [...]

Applied to misc/kernel.git (drm-misc-next).

Thanks!
Maxime

Patch

diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst
index 13d3627d8bc0..b98b98359c90 100644
--- a/Documentation/gpu/drm-kms.rst
+++ b/Documentation/gpu/drm-kms.rst
@@ -496,6 +496,13 @@  addition to the one mentioned above:
 
 * An IGT test must be submitted where reasonable.
 
+For historical reasons, non-standard, driver-specific properties exist. If a KMS
+driver wants to add support for one of those properties, the requirements for
+new properties apply where possible. Additionally, the documented behavior must
+match the de facto semantics of the existing property to ensure compatibility.
+Developers of the driver that first added the property should help with those
+tasks and must ACK the documented behavior if possible.
+
 Property Types and Blob Property Support
 ----------------------------------------