Version: unspecified (using KDE 4.6.2) OS: Linux I have two KDE sessions. Brightness in both are set to maximum. When I switch to the second KDE session brightness remains at the maximum. When I switch back from the second to the first KDE session, brightness sometimes is reduced to its minimum. I think the "sometimes" depends on the time. I first though it happens always but now found that it does not happen when I switch back from the second to the first session immediately. I thus think the powermanagement of the first session triggers darkening the display on switching cause the first KDE session has been inactive for some time. But it even does not brighten the display when I am active again. Reproducible: Didn't try Steps to Reproduce: - open two KDE sessions - set brightness to maximum on both sessions - on KDE session one I had "Performance" profile - on KDE session two no profile was selected (I guess due to the change of standard profiles with KDE 4.6, I now test with "Performance" profile as well) - switch to second session (Ctrl-Alt-F8) - wait a while - switch back to first session (Ctrl-Alt-F7) Actual Results: Display darkens to the minimum brightness. Expected Results: Brightness should remain at the maximum. I will test with "Performance" profile on both KDE sessions now. Then probably with "Powersafe" profile on both sides.
I think I have demystified this: - the issue also appears when switching from first KDE session to the second one as soon as I switched the second one to the new standard "Performance" profile - the issue happens whenever a profile is active that has a display darkening timeout - the issue is that powermanament daemon correctly appplies the darkening timeout on any session that is inactive, *but* - when switching to a session that has the darkening timeout exceeded powermanagement does not seem to recognize that this session is in use again - thus the display stays dark while the daemon should restore maximum brightness again This might not even be a new KDE 4.6.2 issue, but just an issue with using profiles with brightness darkening timeouts. Thus consequently a workaround should be to disable the darkening timeout on every session.
Bug 264983 - randomly changing brightness settings of display might be related to this.
*** This bug has been marked as a duplicate of bug 272438 ***
*** Bug 264333 has been marked as a duplicate of this bug. ***