AMD gpu: Some kernel versions are affected by Adaptive Backlight bug

[griffi-gh]

There seems to be a bug in some 6.12.x-line kernel versions that affects the amd7000 series fw13 laptops

The bug also affects some other laptops with AMD Vega and 6**M/7**M series integrated GPUs.

I think it has already been fixed in the latest kernel (not sure which one? has the patch been merged at all?)
But 6.12.5-6.12.8 (inclusive) are definitely affected (could be 6.12.9 as well), and I have experienced this issue randomly on my own machine.

The workaround is to disable ABM (Vari-Bright) with amdgpu.abmlevel=0 (which could result in higher power consumption on battery), or use the "Performance" power profile while on battery (which disables ABM as well);

The proper solution is of course to upgrade/downgrade the kernel, but I was wondering if a workaround could (or should?) be added here as well to prevent confusion in the future.

sources (framework forums, has a video of the issue; rapid flashing):
https://community.frame.work/t/solved-display-backlight-failing-after-resuming-from-hibernate/63306

the bug itself (+patches):
https://lore.kernel.org/all/[email protected]/
https://gitlab.freedesktop.org/drm/amd/-/issues/3853#note_2714815
https://discussion.fedoraproject.org/t/screen-blinks-blank-then-completely-black-after-updates/140523