SUMMARY On Plasma 6.2, setting the "Change screen brightness" slider to any value, on any power state - does not appear to have any effect on the system at any point. STEPS TO REPRODUCE 1. Make sure the laptop is connected to AC power. 2. Open Power Management KCM 3. Under "On AC Power" check the "Change screen brightness" checkbox and set the slider to some value (lets say - 75%"). 4. Under "On Battery" check the "Change screen brightness" checkbox and set the slider to some other value (lets say - 50%). 5. Unplug the AC power cable. 6. Re-plug the AC power cable. OBSERVED RESULT The laptop screen brightness does not change. EXPECTED RESULT The laptop screen brightness should change to 50% when power is disconnected, and then change to 75% when the power is reconnected (I think, regardless of what the brightness was set to before). SOFTWARE/OS VERSIONS Operating System: KDE neon Testing Edition KDE Plasma Version: 6.2.5 KDE Frameworks Version: 6.10.0 Qt Version: 6.8.1 Kernel Version: 6.8.0-51-generic (64-bit) Graphics Platform: Wayland Processors: 20 × 12th Gen Intel® Core™ i7-12700H Memory: 31.0 GiB of RAM Graphics Processor: Mesa Intel® Graphics ADDITIONAL INFORMATION It appears that all of the other "Display and Brightness" toggles in the Power Management KCM do not function either: setting "Dim automatically" doesn't dim the screen after the specified time, no "Turn off screen". I haven't played with "Change keyboard brightness" yet, so can't verify if that works.
This could be a kernel or upower bug.
I think there may have been a misunderstanding: 1. I understand "RESOLVED INTENTIONAL" to mean that the behavior described is "as intended" - which I don't understand how can that be the case: are you saying that having a bunch of UI that does nothing is intentional? 2. The comment makes more sense - is this an issue with another software lower down the stack (in which case "RESOLVED UPSTERAM" or "RESOLVED NOTABUG") may have been more suitable. Regarding the actual content of the comment: To my understanding this is not an issue with either the ability of powerdevil to control brightness (the brightness control widget works fine, as well as keyboard shortcut binding and the D-Bus API), nor with the ability of powerdevil to detect the power state: ``` $ qdbus org.kde.Solid.PowerManagement /org/kde/Solid/PowerManagement org.kde.Solid.PowerManagement.currentProfile AC ... $ qdbus org.kde.Solid.PowerManagement /org/kde/Solid/PowerManagement org.kde.Solid.PowerManagement.currentProfile Battery ``` So it doesn't seem like lack of information that is needed for PowerDevil to perform actions, nor lack of ability to perform actions - it seems that PowerDevil just fails to perform actions it promised to take, that it can take, on the basis of information that it has.
Oops, I didn't actually intent to close this, sorry.
Hi - merging this in with the existing issue report where this one is being tracked. Thanks! *** This bug has been marked as a duplicate of bug 494956 ***