Display brightness turn down on battery mode after 10 seconds (power manager settings ignored)

[Lars Volker]

On my Thinkpad T400 in battery mode, the display brightness turns considerably lower after not moving the mouse or typing anything for about 10 seconds. The problem is also described here (http://askubuntu.com/questions/65969/display-brightness-goes-two-shades-darker-if-i-am-idle-for-10-11-seconds) but in XFCE the dialog described in the solution doesn't exist.

I already tried changing the duration and the brightness in the xfce4-power-manager-settings dialog, but all changes there are effectively ignored. I also tried killing the power manager, killing upowerd, killing xscreensaver, but the behaviour persists.

I don't know where to look for the setting causing this behaviour, but nonetheless xfce4-power-manager-settings should detect, that its settings won't take effect and should warn about this.

ProblemType: Bug
DistroRelease: Ubuntu 11.10
Package: xfce4-power-manager 1.0.10-4ubuntu0.1
ProcVersionSignature: Ubuntu 3.0.0-15.24-generic 3.0.13
Uname: Linux 3.0.0-15-generic x86_64
NonfreeKernelModules: fglrx
ApportVersion: 1.23-0ubuntu4
Architecture: amd64
Date: Mon Dec 26 01:03:12 2011
InstallationMedia: Xubuntu 10.04 "Lucid Lynx" - Alpha amd64 (20100415)
ProcEnviron:
 PATH=(custom, user)
 LANG=de_DE.UTF-8
 SHELL=/bin/bash
SourcePackage: xfce4-power-manager
UpgradeStatus: Upgraded to oneiric on 2011-10-24 (62 days ago)

[Lars Volker (lv)]

I just found, that gnome-settings-daemon was running on my system and that killing it got me rid of that issue. However I still think xfce4-power-manager-settings should have told me that there was an issue with the configuration. Also, when starting gnome-settings-daemon on the command line and waiting 10 seconds, the following pops up as soon as the display backlight gets dimmed:

(gnome-settings-daemon:16612): power-plugin-WARNING **: IsInhibited failed: GDBus.Error:org.freedesktop.DBus.Error.ServiceUnknown: The name org.gnome.SessionManager was not provided by any .service files

I also found the backlight dimming options in gconf-editor in /apps/gnome-power-manager/backlight and deactivated all entries, which didn't help.

[Lars Volker (lv)]

I also just figured out here (http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=650086) that you can manually adjust the time after which the backlight gets dimmed with the following command:

gsettings set org.gnome.settings-daemon.plugins.power idle-dim-time <seconds>

[Nokir (nokir)]

xfce4-power-manager seems to work normally after i did

gsettings set org.gnome.settings-daemon.plugins.power idle-dim-time 0

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Maarten Bezemer (veger)]

Thanks for taking the time to find this bug in the upstream bug tracking system this is a tremendous help. Launchpad has the ability to watch lots of upstream bug trackers and this can be done by following the procedure documented at https://wiki.ubuntu.com/Bugs/Watches. I've added the bug watch for this bug report.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.