In kernel 6.14 amdgpu, this change was made and this dc debug mask flag can be used to disable this by setting kernel paramater amdgpu.dcdebugmask=0x40000
I didn’t like it at first but got used to it. I ( after some time ) disabled it but then it felt a bit too bright, so I enabled it again ( removing kernel parameter )
and before you make this change, check your kernel logs ( sudo dmesg or journalctl -b -k) to see if it says something like…
amdgpu: [drm] Using custom brightness curve
if it does, that kernel parameter will disable that