http://bugzilla.opensuse.org/show_bug.cgi?id=1203084 Bug ID: 1203084 Summary: Brightness keys not working in Plasma in Panasonic CF-AX2 Classification: openSUSE Product: openSUSE Tumbleweed Version: Current Hardware: x86-64 OS: openSUSE Tumbleweed Status: NEW Severity: Minor Priority: P5 - None Component: KDE Workspace (Plasma) Assignee: opensuse-kde-bugs@opensuse.org Reporter: email@chanjp.me QA Contact: qa-bugs@suse.de Found By: --- Blocker: --- On a Panasonic CF-AX2, installed with the latest (at this time of publishing) version of Tumbleweed, the brightness keys appear to fail to work on KDE Plasma despite showing the brightness indicator on-screen. Probing with ls /sys/class/backlight/ showed two options: intel_backlight panasonic Using echo 800 | sudo tee /sys/class/backlight/intel_backlight/brightness I was able to change the brightness on my screen, but not when the options were passed to "panasonic" as the brightness keys were doing. Further investigation using the `brightnessctl -l` command to see and set brightness confirmed brightness values were being pushed to one device only (panasonic), and not the one that actually affected brightness ("intel_backlight). As an interesting aside, I installed the Enlightenment desktop environment which as part of its boot-up process, popped up a message about acpi I couldn't catch fast enough and automagically just worked for brightness control. While trying to fix this bug, I encountered this entry for Powerdevil in KDE which seems to indicate that this kind of behaviour should be fixed when encountering multiple backlight devices. https://invent.kde.org/plasma/powerdevil/-/commit/761fc8a4bf4bd70bcd9aca63fc... Fix: Adding the following to the kernel boot option resolves the issue: acpi_osi=linux acpi_backlight=video The second entry is probably the most important of the two options, but I figured I might as well play it safe with both acpi options. After confirming brightness toggle now works, ls /sys/class/backlight/ Now shows: acpi_video0 intel_backlight panasonic -- You are receiving this mail because: You are on the CC list for the bug.