Arch Linux

Niwan

Member

Registered: 2025-10-25

Posts: 3

[SOLVED] no ability to change brightness

I just did a fresh install of arch and my brightness changing is not working (neither brillo nor brightnessctl nor light) even though it was working on my previous arch install. I haven't changed anything related to udev or similar stuff like that. I already tried all the different combinations of amdgpu.backlight=... acpi_backlight=... and I also already tried with non long term support kernel, and its the same. I haven't been able to solve this by applying the solutions that other other people applied to solve it in other posts. here is all the relevant information i could think off adding, let me know if i should paste something else.

$ ls -la /sys/class/backlight/
total 0
drwxr-xr-x  2 root root 0 Oct 25 18:13 .
drwxr-xr-x 75 root root 0 Oct 25 17:49 ..

$ lspci | grep -E "VGA|3D"
01:00.0 VGA compatible controller: NVIDIA Corporation GA106M [GeForce RTX 3060 Mobile / Max-Q] (rev a1)
06:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Rembrandt [Radeon 680M] (rev c8)

$ lsmod | grep -E "video|backlight"
uvcvideo              184320  0
videobuf2_vmalloc      20480  1 uvcvideo
uvc                    12288  1 uvcvideo
videobuf2_memops       16384  1 videobuf2_vmalloc
videobuf2_v4l2         40960  1 uvcvideo
videobuf2_common       94208  4 videobuf2_vmalloc,videobuf2_v4l2,uvcvideo,videobuf2_memops
videodev              397312  2 videobuf2_v4l2,uvcvideo
mc                     90112  4 videodev,videobuf2_v4l2,uvcvideo,videobuf2_common
video                  81920  1 amdgpu
wmi                    28672  3 hp_wmi,video,wmi_bmof

$ sudo dmesg | grep -i backlight

$ cat /proc/cmdline
BOOT_IMAGE=/vmlinuz-linux-lts root=UUID=67fba9f7-1f14-49cc-8876-eeb431d3c72d rw loglevel=3 quiet

$ cat /etc/udev/rules.d/*backlight*
zsh: no matches found: /etc/udev/rules.d/*backlight*

$ cat /usr/lib/udev/rules.d/*backlight*
zsh: no matches found: /usr/lib/udev/rules.d/*backlight*

$ sudo lspci -k | grep -A 3 -E "VGA|3D"
01:00.0 VGA compatible controller: NVIDIA Corporation GA106M [GeForce RTX 3060 Mobile / Max-Q] (rev a1)
        DeviceName: NVIDIA Graphics Device
        Subsystem: Hewlett-Packard Company Device 8a43
        Kernel modules: nouveau
--
06:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] Rembrandt [Radeon 680M] (rev c8)
        DeviceName:  Onboard IGD
        Subsystem: Hewlett-Packard Company Device 8a43
        Kernel driver in use: amdgpu

$ ls /sys/class/drm/*/device/backlight/
zsh: no matches found: /sys/class/drm/*/device/backlight/

$ find /sys/devices -type d -name "*backlight*"

$ uname -r
6.12.53-1-lts

$ pacman -Q linux-firmware
linux-firmware 20251021-1

$ lsmod | grep hp_wmi
hp_wmi                 40960  0
sparse_keymap          12288  1 hp_wmi
rfkill                 40960  5 hp_wmi,bluetooth,cfg80211
platform_profile       12288  2 hp_wmi,amd_pmf
wmi                    28672  3 hp_wmi,video,wmi_bmof

$ sudo modprobe video

$ sudo modprobe acpi_video
modprobe: FATAL: Module acpi_video not found in directory /lib/modules/6.12.53-1-lts

$ sudo ddcutil detect
No /dev/i2c devices exist.
ddcutil requires module i2c-dev.

Last edited by Niwan (2025-10-31 22:27:21)

croyleje

Member

Registered: 2020-05-05

Posts: 6

Re: [SOLVED] no ability to change brightness

Do you have acpi and brightnessctl installed if so try running brightnessctl --list you should get a list of the leds and backlights that are controllable  if there not installed you may have to reboot after installing them to get the devices to show in brightnessctl.

Niwan

Member

Registered: 2025-10-25

Posts: 3

Re: [SOLVED] no ability to change brightness

I figured it out, i had to install nvidia-open drivers

seth

Member

From: Don't DM me only for attention

Registered: 2012-09-03

Posts: 70,964

Re: [SOLVED] no ability to change brightness

\o/
Please always remember to mark resolved threads by editing your initial posts subject - so others will know that there's no task left, but maybe a solution to find.
Thanks.

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Niwan

Member

Registered: 2025-10-25

Posts: 3

Re: [SOLVED] no ability to change brightness

Okay! Is the way i just did it good?

seth

Member

From: Don't DM me only for attention

Registered: 2012-09-03

Posts: 70,964

Re: [SOLVED] no ability to change brightness

Good enough
(Typically people prepend "[SOLVED] ")

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