Hello,
After updating from 6.8.9 to 6.9.1 I noticed a bug on my HP Envy x360 with AMD Ryzen 5 4500U.
#regzbot introduced: v6.8.9..v6.9.1
After waking up from sleep brightness is set to max level, ignoring previous value.
With the help of Arch Linux team, we was able to track bad commit to this: https://gitlab.freedesktop.org/agd5f/linux/-/commit/63d0b87213a0ba241b3fcfba...
I have tested this on latest mainline kernel:
Results after waking up:
cat /sys/class/backlight/amdgpu_bl1/{brightness,actual_brightness}
12 252
Then, on exact this commit (63d0b87213a0ba241b3fcfba3fe7b0aed0cd1cc5), result is the same.
Then, on commit just before this one (aeaf3e6cf842):
cat /sys/class/backlight/amdgpu_bl1/{brightness,actual_brightness}
12 12
I hope I included all relevant information, more info can be found here:
https://gitlab.archlinux.org/archlinux/packaging/packages/linux/-/issues/52