screen brightness can't be controlled

[blacktree]

Hi

I am using debian 12 on HP victus with two graphics card Nvidia 3050 and amd radeon (integrated). I dual booted debian on this laptop but I am not being able to control the brightness. I am using KDE plamsa. During shutdown, it takes a lot of time to shutdown and after checking the logs, backlighthelper is not shutting down properly. I tried to change desktop environment to cinnamon but I am facing same problem but with different service that controls the brightness in cinnamon. I have updated both nvidia drivers and amd drivers but nothing is working.
the output for
ls /sys/class/backlight/ is amdgpu_bl1

I am new to debian please help

[bbbhltz]

Could you try launching an X11 session of one of those Desktop Environments? It may be that Wayland and Nvidia (or AMD) work poorly together in your case.

Update: Sorry, I just saw that Cinnamon is X11, you can ignore this suggestion I think

[blacktree]

I tried those steps, but they didn't resolve the issue. In Wayland, I can see the brightness control slider, but it doesn't actually change the brightness. In X11, the brightness control slider isn't visible at all.

[ajgreeny]

Have you tried putting the cursor on the battery or power icon in the panel and using the scroll-wheel or touchpad scroll (assuming there is such an icon in KDE which I don't use).
That works in two laptops that I use, not HP I accept but brightness changes simply by scrolling, no button presses needed.

[bbbhltz]

This post may help

https://forums.debian.net/viewtopic.php ... 38#p801438

[blacktree]

This post may help

https://forums.debian.net/viewtopic.php ... 38#p801438

I tried this

Code: Select all

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash acpi_osi=! idle=nomwait acpi_backlight=native"

but then debian didn't boot. I then pressed e and edited to remove those lines and then revered that to default that is "quiet"

Have you tried putting the cursor on the battery or power icon in the panel and using the scroll-wheel or touchpad scroll (assuming there is such an icon in KDE which I don't use).
That works in two laptops that I use, not HP I accept but brightness changes simply by scrolling, no button presses needed.

Code: Select all

[FAILED] Failed to start systemd-backlight@backlight:amdgpu_bl0.service - Load/Save Screen Backlight Brightness of backlight:amdgpu_bl0.

This is the message I am getting when I am starting it or shutting it down and it is taking a lot of time to shutdown as well (dbus.service)

[bbbhltz]

Code: Select all

systemctl status systemd-backlight@backlight:amdgpu_bl0.service

Will give you some info including Main PID.

Then do

Code: Select all

journalctl -b _PID=###

Where ### is the PID. What is the output of that command?

...

Another idea would be to change your kernel arguments to

Code: Select all

GRUB_CMDLINE_LINUX_DEFAULT="quiet acpi_backlight=vendor"

[blacktree]

Code: Select all

systemctl status systemd-backlight@backlight:amdgpu_bl0.service

Will give you some info including Main PID.

Then do

Code: Select all

journalctl -b _PID=###

Where ### is the PID. What is the output of that command?

...

Another idea would be to change your kernel arguments to

Code: Select all

GRUB_CMDLINE_LINUX_DEFAULT="quiet acpi_backlight=vendor"

Here is the output when checking the status:

Code: Select all

systemctl status systemd-backlight@backlight:amdgpu_bl0.service
systemd-backlight@backlight:amdgpu_bl0.service - Load/Save Screen Backlight Brightness of backlight:amdgpu_bl0
     Loaded: loaded (/lib/systemd/system/systemd-backlight@.service; static)
     Active: inactive (dead)
       Docs: man:systemd-backlight@.service(8)

When I started the service using this command:

Code: Select all

systemctl start systemd-backlight@backlight:amdgpu_bl0.service

and then checked its log using journalctl, it showed no entries.

I also updated the kernel arguments as suggested, but now the brightness control scrollbar is not visible, and the keyboard is not showing any pop-up when adjusting brightness. After updating the kernel arguments, I checked the service again, but the results remained the same.

[blacktree]

Update,

I installed these packages

Code: Select all

sudo apt-get install xserver-xorg-video-amdgpu
sudo apt-get install firmware-amd-graphics
sudo apt-get install libdrm-amdgpu1
sudo apt-get install libdrm-amdgpu-amdgpu1

after that my screen brightness is reduced to min and when I try to increase it using brightness control, it is getting slightly darker.
on checking the status of service that is responsible

Code: Select all

systemctl status systemd-backlight@backlight:amdgpu_bl1.service
● systemd-backlight@backlight:amdgpu_bl1.service - Load/Save Screen Backlight Brightness of backlight:amdgpu_bl1
     Loaded: loaded (/lib/systemd/system/systemd-backlight@.service; static)
     Active: active (exited) since Sat 2024-08-31 18:31:48 IST; 30min ago
       Docs: man:systemd-backlight@.service(8)
    Process: 468 ExecStart=/lib/systemd/systemd-backlight load backlight:amdgpu_bl1 (code=exited, status=0/SUCCESS)
   Main PID: 468 (code=exited, status=0/SUCCESS)
        CPU: 13ms

Aug 31 18:31:48 alpha5 systemd[1]: Starting systemd-backlight@backlight:amdgpu_bl1.service - Load/Save Screen Backlight Brightness of backlight:amdgpu_bl1...
Aug 31 18:31:48 alpha5 systemd-backlight[468]: amdgpu_bl1: Saved brightness 0 is too low; increasing to 12.
Aug 31 18:31:48 alpha5 systemd[1]: Finished systemd-backlight@backlight:amdgpu_bl1.service - Load/Save Screen Backlight Brightness of backlight:amdgpu_bl1.

and for journalctl

Code: Select all

journalctl _PID=468
Aug 31 06:06:46 alpha5 systemd-fsck[468]: fsck.fat 4.2 (2021-01-31)
Aug 31 06:06:46 alpha5 systemd-fsck[468]: /dev/nvme0n1p1: 218 files, 17934/65536 clusters
-- Boot 1be1c458000941b28eda91af29680ab9 --
Aug 31 18:31:48 alpha5 systemd-backlight[468]: amdgpu_bl1: Saved brightness 0 is too low; increasing to 12.

If I tries to control brightness, at 50% the brightness is more than at 100% but none at maximum. When I checked /sys/class/backlight/amdgpu_bl1/brightness file it is working the same way 255 is max brightness and at 128 it is more bright than 255. Trying different package to control brightness is giving the same result.

these are some missing packages that is being shown. I tried to copy drivers from official repo but still these are missing.

Code: Select all

sudo update-initramfs -u
update-initramfs: Generating /boot/initrd.img-6.1.0-25-amd64
W: Possible missing firmware /lib/firmware/amdgpu/ip_discovery.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/vega10_cap.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/sienna_cichlid_cap.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/navi12_cap.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/aldebaran_cap.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/gc_11_0_0_toc.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/sienna_cichlid_mes1.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/sienna_cichlid_mes.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/navi10_mes.bin for module amdgpu
W: Possible missing firmware /lib/firmware/amdgpu/gc_11_0_3_mes.bin for module amdgpu

[Lumipyry]

I had no brightness control in my fresh Debian 12 KDE Plasma install (at 20th of October 2024).

$ sudo journalctl -k | grep -i "brightness\|backlight\|pwm"
gave:

Code: Select all

$ mac kernel: radeon 0000:01:00.0: [drm] Skipping radeon atom DIG backlight registration

The machine is a mid 2011 iMac which has Intel CPU.
And apparently both Intel and and AMD GPUs:

$ inxi -G

Code: Select all

Graphics:
  Device-1: Intel 2nd Generation Core Processor Family Integrated Graphics
    driver: i915 v: kernel
  Device-2: AMD Whistler [Radeon HD 6630M/6650M/6750M/7670M/7690M]
    driver: radeon v: kernel
  Device-3: Apple FaceTime HD Camera (Built-in) type: USB driver: uvcvideo
  Display: wayland server: X.Org v: 1.22.1.9 with: Xwayland v: 22.1.9
    compositor: kwin_wayland driver: X: loaded: modesetting,radeon
    unloaded: fbdev,vesa dri: r600 gpu: radeon resolution: 1: 1920x1080~60Hz
    2: 1920x1080~60Hz
  API: OpenGL v: 4.5 Mesa 22.3.6 renderer: AMD TURKS (DRM 2.50.0 /
    6.10.11+bpo-amd64 LLVM 15.0.6)

Solution

was to install new kernel from backports, as @blackbird suggests in [Solved] Brightness controls change but actual brightness does not.

$ sudo journalctl -k | grep -i "brightness\|backlight\|pwm" after new kernel

Code: Select all

mac kernel: [drm] radeon atom DIG backlight initialized

The current default kernel in Debian 12 is 6.1.0.26-amd64 and with backports comes kernel 6.10.11+bpo-amd64.

P.S. @sunrat has written a fantastic guide of [HowTo] Install a kernel from Backports