[Bug 2148630] Re: Brightness control does not work at all on ROG Zephyrus G14 GA403WP laptop

Thanks for the report, and don't worry about filing against gnome- control-center — it's a natural first guess since brightness settings live in the Settings app. That said, on Ubuntu the actual backlight control is handled by the kernel (ACPI/WMI drivers like asus-wmi) which expose interfaces under /sys/class/backlight/ or /sys/class/iio/, and then by gnome-settings-daemon and mutter to make the controls work on the desktop side. The Settings panel itself just reads what those layers provide. Because this is on a daily build with kernel 7.0-rc7, it's quite possible the kernel hasn't yet created the right backlight interfaces for your OLED panel. To figure out which layer is responsible, could you run the following on the same system (or a later daily build if one is available): 1. Check whether the kernel sees any backlight devices: ls /sys/class/backlight/ 2. If that directory is empty or shows nothing relevant, check for IIO-based sensors instead: ls /sys/class/iio/device/ 3. Look for asus_wmi or ACPI video driver messages in dmesg: dmesg | grep -i "asus_wmi\|acpi_video\|oled_backlight\|backlight" 4. Check the journal for any errors when you try to change brightness (press a brightness key, wait a moment, then run): journalctl --since "10 minutes ago" | grep -i "brightness\|backlight\|asus_wmi\|g-s-d-power" If step 1 shows a device (for example asw_backlight or oled_backlight), the kernel sees it and the issue may be in gnome-settings-daemon or mutter. If the directory is empty, the kernel driver likely hasn't initialized support for your panel yet, which would be a kernel-side fix. Also, could you confirm whether the Fn+F5/F6 (or whatever) brightness keys produce any on-screen indicator at all? Even if brightness doesn't change, seeing the OSD would help narrow things down. I've noted that bug #2085359 as a related report — different model but same symptom class. If you can share the output of the commands above, I can help determine whether this should be refiled against the linux kernel package. Thanks for your patience with this and your input helps push the support forward. ** Changed in: linux (Ubuntu) Status: New => Incomplete -- You received this bug notification because you are subscribed to linux in Ubuntu. Matching subscriptions: Bgg, Bmail, Nb https://bugs.launchpad.net/bugs/2148630 Title: Brightness control does not work at all on ROG Zephyrus G14 GA403WP laptop Status in linux package in Ubuntu: Incomplete Status in linux source package in Resolute: New Bug description: I am not sure if this is the right package to raise this bug on. The brightness control for the built in display on this laptop does not work at all, booted into the Resolute daily live distro. Ubuntu 26.04 "Resolute Raccoon" - Daily amd64 (20260415) Happy to pull logs once I can work out which package is actually responsible for display control. This is an OLED so it's pretty critical for dimming to work. ProblemType: Bug DistroRelease: Ubuntu 26.04 Package: gnome-control-center 1:50.0-0ubuntu4 ProcVersionSignature: Ubuntu 7.0.0-13.13-generic 7.0.0-rc7 Uname: Linux 7.0.0-13-generic x86_64 NonfreeKernelModules: zfs ApportVersion: 2.34.0-0ubuntu2 Architecture: amd64 CasperMD5CheckResult: pass CasperVersion: 26.04.2 CloudArchitecture: x86_64 CloudID: nocloud CloudName: unknown CloudPlatform: nocloud CloudSubPlatform: seed-dir (/var/lib/cloud/seed/nocloud) CurrentDesktop: ubuntu:GNOME Date: Fri Apr 17 01:20:53 2026 LiveMediaBuild: Ubuntu 26.04 "Resolute Raccoon" - Daily amd64 (20260415) ProcEnviron: LANG=C.UTF-8 PATH=(custom, no user) SHELL=/bin/bash TERM=xterm-256color XDG_RUNTIME_DIR=<set> SourcePackage: gnome-control-center UpgradeStatus: No upgrade log present (probably fresh install) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2148630/+subscriptions