[Intel-gfx] [PATCH v3 00/14] New uAPI drm properties for color management

[Werner Sembach]

I started work on my proposal for better color handling in Linux display
drivers: https://lkml.org/lkml/2021/5/12/764

In this 3rd revision everything except the generalised Broadcast RGB
implementation is included. I did however not yet include everything suggested
in the feedback for v1 and v2.

I rebased the patch series on drm-tip to have the latest changes in i915's
YCbCr420 handling and to make the intel-gfx ci not fail on merge anymore.

The read only properties are now correctly marked as immutable.

Some questions I already have:

I think Broadcast RGB is really no good name for the property as, at least in
theory, YCbCr can also be "Limited" or "Full". Should the new implementation
have a different name and make "Broadcast RGB" an alias for it? I propose
"preferred color range" as the new name.

I have not tested dp mst (both on AMD and Intel) as i have no adapter for it at
hand. If one can test it, please let me know if things break or not.

I found the DRM_MODE_PROP_ATOMIC flag and from the documentation it sounds like
"max bpc" (and "preferred color format" and "Broadcast RGB") should have it. Is
there a reason it doesn't?

I have not yet looked into dsc and dithering behaviour.

I have already submitted the first two patches separately to the lkml as they fix
potential bugs and don't introduce new uAPI.