I started work on my proposal for better color handling in Linux display drivers: https://lkml.org/lkml/2021/5/12/764
In this 2nd revision the first two read-only properties are now implemented for amdgpu and i915. I post it here to collect collect some additional feedback, if someone sees an improvement opportunity.
I have already commited the first patch in this series independently as it fixes a function already in use.
Some of the feedback from the first post is already implemented.
The actual update of the values is implemented in patch three and four and six and seven in the atomic_commit_tail() function of amdgpu and atomic_commit() function of i915 respectively. They do get updated more often than needed with the current approach, but without harm since just the same value is written again. A check if the update is required would be the same amount of computation.