sibgat
(Sibgat Ul Islam)
January 20, 2025, 9:10am
1
Hello people, I have nvidia gpu on my current workstation and have installed the drivers for it. But the problem i am facing is on wayland i dont see any brightness control or whatsoever. I am pretty much clue less at this point and in need of your help.
Here are some logs:
> nvidia-smi -L
GPU 0: NVIDIA GeForce RTX 3060 (UUID: GPU-46d15a39-51ae-2a5d-14a4-d3858a07abad)
> lspci | grep "VGA"
2b:00.0 VGA compatible controller: NVIDIA Corporation GA104 [GeForce RTX 3060] (rev a1)
> dmesg | grep -i acpi_backlight
[ 0.000000] Command line: BOOT_IMAGE=(hd0,gpt3)/vmlinuz-6.12.9-200.fc41.x86_64 root=UUID=10ed4754-95be-484c-a418-0e3296b0cf2f ro rootflags=subvol=root rhgb quiet rd.driver.blacklist=nouveau modprobe.blacklist=nouveau acpi_backlight=vendor
[ 0.033745] Kernel command line: BOOT_IMAGE=(hd0,gpt3)/vmlinuz-6.12.9-200.fc41.x86_64 root=UUID=10ed4754-95be-484c-a418-0e3296b0cf2f ro rootflags=subvol=root rhgb quiet rd.driver.blacklist=nouveau modprobe.blacklist=nouveau acpi_backlight=vendor
Trying to start the system service throws error. Also tried brightnessctl and xrandr none of them changes the brightness.
> sudo systemctl status systemd-backlight@backlight.service
× systemd-backlight@backlight.service - Load/Save Screen Backlight Brightness of backlight
Loaded: loaded (/usr/lib/systemd/system/systemd-backlight@.service; static)
Drop-In: /usr/lib/systemd/system/service.d
└─10-timeout-abort.conf, 50-keep-warm.conf
Active: failed (Result: exit-code) since Mon 2025-01-20 15:06:56 +06; 5s ago
Invocation: b547833638ab41d1a9e96628d7fd236a
Docs: man:systemd-backlight@.service(8)
Process: 66747 ExecStart=/usr/lib/systemd/systemd-backlight load backlight (code=exited, status=1/FA>
Main PID: 66747 (code=exited, status=1/FAILURE)
Mem peak: 5M
CPU: 9ms
Jan 20 15:06:56 fedora systemd[1]: Starting systemd-backlight@backlight.service - Load/Save Screen Backl>
Jan 20 15:06:56 fedora systemd-backlight[66747]: Requires a subsystem and sysname pair specifying a back>
Jan 20 15:06:56 fedora systemd[1]: systemd-backlight@backlight.service: Main process exited, code=exited>
Jan 20 15:06:56 fedora systemd[1]: systemd-backlight@backlight.service: Failed with result 'exit-code'.
Jan 20 15:06:56 fedora systemd[1]: Failed to start systemd-backlight@backlight.service - Load/Save Scree>
lines 1-17/17 (END)
Please let me know if you need anymore infos, thanks.
I sometimes use ‘light’ as brightness control.
sudo dnf install light
man light
sibgat
(Sibgat Ul Islam)
January 20, 2025, 12:53pm
3
does not works, and on the list, there are no driver or anything to control the screen brightness, maybe it will work on x11, its the same situation i am facing with every other brightness control app
Works for me on Wayland. It is a command line interface.
To decrease brightness by 10%
light -U 10
to increase brightness by 10%
light -A 10
sibgat
(Sibgat Ul Islam)
January 21, 2025, 6:09am
5
well there are no backlight controller and the backlight service does not runs at all.
can you show me the output of
sudo systemctl status systemd-backlight@backlight.service
please?
Ok, so I can see now that your systemd-backlight@backlight.service is failing to load.
1 Like
What is the contents of your /etc/default/grub ?
A similar issue was solved on the Arch forums by adding acpi_backlight=vendor to
GRUB_CMDLINE_LINUX_DEFAULT
https://bbs.archlinux.org/viewtopic.php?id=211967
1 Like
sibgat
(Sibgat Ul Islam)
January 21, 2025, 12:03pm
9
I have set it to vendor before, but no results.
I have tried most of the solutions i found online but none of them works (and it is with every fedora wayland i tried from, 38 with nvidia gpu)
What monitor are you using? Or are you on a laptop?
Also, just to check as I see you have tried many things, that your system is up to date?
Are you running Gnome on Fedora 41?
And what Nvidia driveres are you using?
sibgat
(Sibgat Ul Islam)
January 21, 2025, 12:13pm
11
yes, gnome on fedora 41, updated, on a desktop.
Monitor: Phillips 226E.
Brightness control works on x11 ( i had the same issue with previous fedora + wayland so had to switch to x11)
1 Like
Has the problem only occurred recently? I have recently seen some issues on the forums with mesa drivers that have been solved by downgrading, but I would have to look into whether that could be the case. Hopefully someone else will chime in soon.
Not the answer you are looking for, but can the monitor control its own brightness?
1 Like
I think this is the key problem but I don’t know how or where to specify the subsystem and sysname pair.
systemd-backlight[66747]: Requires a subsystem and sysname pair specifying a back>
Here is the github page for backlight.c
Well I am learning a lot about the backlight system!
What is the contents of your /sys/class/backlight/ ?
This Arch page is interesting Backlight - ArchWiki
I think we need to know the name of your interface, with reference to the above link section 1,1
sibgat
(Sibgat Ul Islam)
January 21, 2025, 1:01pm
15
yup it has, thats why i still have my eye sight XD
1 Like
sibgat
(Sibgat Ul Islam)
January 21, 2025, 1:02pm
16
yea i have been trying to find that sysname pair thing on the internet, but had no luck, did not see the source code tho
sibgat
(Sibgat Ul Islam)
January 21, 2025, 1:04pm
17
I was digging into this, my backlight has no files or folders or whatsover, could not figure out why, thought of creating them manually but if it breaks the OS…
> ls /sys/class/backlight/
**nothing**
sibgat
(Sibgat Ul Islam)
January 21, 2025, 1:05pm
18
I have also tried with diff values,
acpi_backlight=video
acpi_backlight=vendor
acpi_backlight=native
but still no luck.
sibgat
(Sibgat Ul Islam)
January 21, 2025, 1:09pm
19
i know one thing that the gpu is working and identified across the system except for the brightness part
With no entry at /sys/class/backlight nothing (well nothing ACPI) is managing your backlight.
Which Nvidia drivers are you using, and how did you install them?