This bug seems to had make a comeback since driver 475, where brightness could not be changed and was stuck on a low value. Now, the opposite occurs, where brightness is stuck on a high value instead.
OS: Fedora 39
Running Wayland, but also happens on X11.
I am running Ubuntu 23.10 on an nVIDIA GeForce RTX 2060 laptop.
I just installed the New Feature Branch driver 545.29.02 from
I still use following configuration
cat /etc/default/grub
GRUB_CMDLINE_LINUX=ânvidia-drm.modeset=1 acpi_backlight=native nvidia.NVreg_RegistryDwords=EnableBrightnessControl=1â
With driver 535.113.01 this was working fine.
With 545 I have no brightness control at all, not in Ubuntu settings, not with the keys Fn-F5/F6.
This is still with X11, I donât use Wayland.
In the BIOS I have chosen for discrete graphics meaning only nVIDIA and not Intel.
I have experienced the same, it seems to be a regresshion, /sys/class/backlight/nvidia_0/actual_brightness contains the correct brightness value but the actual screen brightness doesnât get changed.
Backlight issues frequently are specific to particular notebook system designs: @BertRAMAerts@Moody.Liu could you please provide detailed information about what notebook systems you are observing these symptoms on?
Thanks. Some of the Legion 5 notebooks have âAdvanced Optimusâ and should be using the nvidia_wmi_ec_backlight driver. Do you have a /sys/class/backlight/nvidia_wmi_ec_backlight device in sysfs?
I notice that you are setting âacpi_backlight=nativeâ on your kernel command line, so perhaps youâve already come to the determination that your system is supposed to be using the NVIDIA dGPU driver for backlight control rather than the in-tree EC backlight driver. (Some notebooks have firmware bugs where ACPI reports the wrong backlight control method, which the âacpi_backlightâ option is meant to work around.)
Oops, I didnât scroll up far enough to see the actual OP of this thread. @robotta2, same question to you: could you please provide detailed information about the notebook system you are observing the symptom on?
Iâve switched the laptop to nvidia only mode in BIOS which disables the integrated gpu and switches the laptop screen to be connected to the nvidia gpu
Thanks, everybody. I was able to reproduce the symptom on a Lenovo Legion laptop in discrete-GPU-only mode: with a 545 driver, I can observe that the value in /sys/class/brightness/nvidia_0/brightness changes when I hit the brightness hotkeys, but the screenâs actual brightness remains unchanged. (I suspect itâs at the maximum level.) With 535, the physical brightness level changes as expected when manipulating the brightness controls. I filed NVIDIA bug #4364327 to track the issue internally.
I also see this regression on an Alienware 17 R4 with a 1070. Bug report attached.
I also find these in the /var/log/messages:
Nov 2 20:32:59 alice audit[1]: SERVICE_START pid=1 uid=0 auid=4294967295 ses=4294967295 subj=system_u:system_r:init_t:s0 msg=âunit=systemd-backlight@backlight:nvidia_0 comm=âsystemdâ exe=â/usr/lib/systemd/systemdâ hostname=? addr=? terminal=? res=failedâ
Nov 2 20:32:59 alice systemd[1]: Starting systemd-backlight@backlight:nvidia_0.service - Load/Save Screen Backlight Brightness of backlight:nvidia_0âŚ
Nov 2 20:32:59 alice systemd-backlight[1020]: nvidia_0: Failed to write system âbrightnessâ attribute: Invalid argument
Nov 2 20:32:59 alice systemd[1]: systemd-backlight@backlight:nvidia_0.service: Main process exited, code=exited, status=1/FAILURE
Nov 2 20:32:59 alice systemd[1]: systemd-backlight@backlight:nvidia_0.service: Failed with result âexit-codeâ.
Nov 2 20:32:59 alice systemd[1]: Failed to start systemd-backlight@backlight:nvidia_0.service - Load/Save Screen Backlight Brightness of backlight:nvidia_0.
Me too. And I suspect more will be affected, since 545 was just moved out of testing in Arch.
Operating System: Arch Linux
Device: Lenovo Legion 5 Pro
Product Name: NVIDIA GeForce RTX 3070 Ti Laptop GPU
The brightness is very glaring⌠Iâm thinking to change to âSwitchable Graphicsâ as a workaround though that is not optimal.
Any chance there is a workaround with NVidia? May be some obscure commandline parameters?
For what itâs worth, I am also afflicted with this, also on Arch Linux. I updated my system today and am now stuck with 100% brightness using driver 545.29.02.
Prior to that, I was able to set brightness by calling xbacklight and also having set EnableBrightnessControl=1 and "Option "Backlight" "acpi_video0" in xorg.conf. See the output of nvidia-bug-report.sh attached.
Currently, I only have one entry (symlink) /sys/class/backlight/nvidia_0, containing files brightness, actual_brightness, etc.
If I xbacklight -set 50 or xbacklight -set 10, both brightness and actual_brightness remain at 100.
I also tried replacing acpi_video0with nvidia_0, and afterwards re-running nvidia-xconfig, just to see if maybe something would change.
Having a similar issue on an HP OMEN Laptop 15-ek018ca running Arch Linux though the brightness is stuck at 50% instead of 100%. Unsure if itâs the same issue, but it did start after upgrading to 545.23.06 and persists on 545.29.02-4
To confirm in case somebody else looks at this thread due to a similar issue, this was fixed with 545.29.06-1 as packaged on arch linux at least for myself