SUMMARY Since the removal of the XRandR backend in Powerdevil (https://phabricator.kde.org/D15261), KDE cannot control my laptop brightness anymore. I already tried all /sys/class/backlight devices, and all values for the acpi_backlight kernel parameter. XRandR works because it calls directly into the NVIDIA driver, as far as I know. SOFTWARE VERSIONS KDE Plasma Version: 5.13.90 KDE Frameworks Version: 5.50 Qt Version: 5.11.2
I think easiest would just be to revert the offending commit, given it was the only change in PowerDevil this cycle, should be pretty safe?
Hmm, can you list all the sysfs interfaces you have?
$ ls /sys/class/backlight acpi_video0 If I boot with acpi_backlight=vendor, then I have: $ ls /sys/class/backlight ideapad Neither of those work.
Git commit 6b93d74675aeb8f6fad26f62f300e4ed6b155ad4 by Kai Uwe Broulik. Committed on 25/09/2018 at 13:57. Pushed by broulik into branch 'Plasma/5.14'. Revert "Remove XRandrBrightness" Apparently there's still graphics cards that rely on this :'( This was the only real change in this cycle, so just reverting it is safe, albeit technically being a dependency change. CCMAIL: kde-distro-packagers@kde.org This reverts commit 7e29869329184d9e2bae6019939e2ecb0eceac0d. M +1 -1 CMakeLists.txt M +6 -1 daemon/backends/CMakeLists.txt M +113 -59 daemon/backends/upower/powerdevilupowerbackend.cpp M +4 -0 daemon/backends/upower/powerdevilupowerbackend.h A +221 -0 daemon/backends/upower/xrandrbrightness.cpp [License: LGPL (v2)] A +51 -0 daemon/backends/upower/xrandrbrightness.h [License: LGPL (v2)] A +124 -0 daemon/backends/upower/xrandrxcbhelper.cpp [License: GPL (v2+)] A +99 -0 daemon/backends/upower/xrandrxcbhelper.h [License: GPL (v2+)] https://commits.kde.org/powerdevil/6b93d74675aeb8f6fad26f62f300e4ed6b155ad4