https://bugs.freedesktop.org/show_bug.cgi?id=107482
--- Comment #9 from Leo Li sunpeng.li@amd.com --- Michel's right about xgamma leaving 0 and max per-channel values unmodified, so the original issue is not-a-bug. Although I'm not sure why there's a difference between amdgpu and dc, I'll have to look into it.