[6.9.1] Problems with brightness and contrast on apu Ryzen 5 5600h (Laptop Honor MagicBook 16)

Description:

The display brightness and colors is broken after update to Linux 6.9.1 on Honor Magicbook 16 (ryzen 5 5600h without discrete gpu) with display by BOEhydis. There is revision of this laptop with another display model.

I don't know how to show you problems with colors (or maybe it's problem with contrast, i bad in it). I just see it. For example: i didn't see any differences between white and gray on 6.9.1.

There are two problems with brightness:

1. actual_brightness isn't equal to brightness:

6.8.9:

[sergoops@arch ~]$ cat /sys/class/backlight/amdgpu_bl1/{brightness,actual_brightness} 
2
2
[sergoops@arch ~]$ cat /sys/class/backlight/amdgpu_bl1/{brightness,actual_brightness} 
62
62
[sergoops@arch ~]$ cat /sys/class/backlight/amdgpu_bl1/{brightness,actual_brightness} 
158
158
[sergoops@arch ~]$ cat /sys/class/backlight/amdgpu_bl1/{brightness,actual_brightness} 
255
255

6.9.1

[sergoops@arch ~]$ cat /sys/class/backlight/amdgpu_bl1/{brightness,actual_brightness} 
2
0
[sergoops@arch ~]$ cat /sys/class/backlight/amdgpu_bl1/{brightness,actual_brightness} 
74
50
[sergoops@arch ~]$ cat /sys/class/backlight/amdgpu_bl1/{brightness,actual_brightness} 
158
119
[sergoops@arch ~]$ cat /sys/class/backlight/amdgpu_bl1/{brightness,actual_brightness} 
255
214

2. After suspend actual_brightness becomes maximum before i press - or + brightness buttons.

Before sleep:

[sergoops@arch ~]$ cat /sys/class/backlight/amdgpu_bl1/{brightness,actual_brightness} 
63
39

After sleep:

[sergoops@arch ~]$ cat /sys/class/backlight/amdgpu_bl1/{brightness,actual_brightness} 
63
252

Logs

I take dmesg | grep amdgpu with next steps: launch laptop, suspend with power button, go out of suspend with power button:

6.8.9_dmesg.txt
6.9.1_dmesg.txt

Additional info:

• package version(s):
  • Linux 6.8.{1-9} - there are no bugs
  • Linux 6.9.1 - there are bugs (6.9.1.arch1-1)
• I will try to git bisect it soon