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.