[REGRESSION] Brightness at max level after waking up from sleep on AMD Laptop

[Hamza Mahfooz]

On 7/31/24 02:38, Linux regression tracking (Thorsten Leemhuis) wrote:
> [+amd-glx, +lkml, +dri-devel]
> 
> On 27.07.24 18:52, serg.partizan at gmail.com wrote:
>>
>> After updating from 6.8.9 to 6.9.1 I noticed a bug on my HP Envy x360
>> with AMD Ryzen 5 4500U.
>>
>> [...]
>> 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/63d0b87213a0ba241b3fcfba3fe7b0aed0cd1cc5
> 
> Hamza Mahfooz, in case you missed it, that is a patch of yours:
> 63d0b87213a0ba ("drm/amd/display: add panel_power_savings sysfs entry to
> eDP connectors") [v6.9-rc1].

Um, for the time being you should be able to set `amdgpu.abmlevel=0` in
the kernel's cmdline to avoid the issue.

> 
>> 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
> 
> Ciao, Thorsten (wearing his 'the Linux kernel's regression tracker' hat)
> --
> Everything you wanna know about Linux kernel regression tracking:
> https://linux-regtracking.leemhuis.info/about/#tldr
> If I did something stupid, please tell me, as explained on that page.
> 
> P.S.:
> 
> #regzbot introduced: 63d0b87213a0ba241
-- 
Hamza