On login ignores setting, turns off screen after idle timeout

[Jani Uusitalo]

Steps to reproduce:
1. Disable power saving
2. (Re-)boot (logoff may suffice, though I've not tested this)
3. Login and don't touch mouse or keyboard after that
4. Wait

What happens:
Within half an hour (on my system at least) the display signal is turned off (monitor reports "No signal").

What you expect to happen:
The screen to stay on as indicated by power saving settings.

Additional info:
1. Any keyboard or mouse activity seems to make it obey the setting: after that the screen won't go blank on its own (irregardless of whether or not the bug has manifested itself during the session).
2. I've disabled screensaver as well, though that probably doesn't concern this bug.
3. From bug #854624's comments I picked up this settings listing command, in case it helps:

jani@saegusa:~$ for c in `dconf list /org/gnome/settings-daemon/plugins/power/`; do echo -n "/org/gnome/settings-daemon/plugins/power/${c}="; dconf read /org/gnome/settings-daemon/plugins/power/${c}; done
/org/gnome/settings-daemon/plugins/power/sleep-display-ac=0
/org/gnome/settings-daemon/plugins/power/sleep-display-battery=0

ProblemType: Bug
DistroRelease: Ubuntu 12.04
Package: gnome-power-manager 3.2.1-1
ProcVersionSignature: Ubuntu 3.2.0-2.6-generic 3.2.0-rc3
Uname: Linux 3.2.0-2-generic x86_64
ApportVersion: 1.90-0ubuntu1
Architecture: amd64
CheckboxSubmission: 09ae689090491ca53449589269e4bfd8
CheckboxSystem: edda5d4f616ca792bf437989cb597002
Date: Sun Dec 4 17:46:51 2011
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
SourcePackage: gnome-power-manager
UpgradeStatus: Upgraded to precise on 2011-12-01 (2 days ago)

[Launchpad Janitor (janitor)]

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

[tdeering (tomdeering7)]

Confirmed on 12.10 Quantal Quetzal. This exact problem began happening to me after an upgrade from 12.04 to 12.10.

This seems to be a bug with the upgrade process screwing up power management settings.

[Jani Uusitalo (uusijani)]

IN 12.04 at least, this seems to be tied to Xorg's blanking which by default happens after 10 minutes/600 seconds. It can be unset via xset on the commandline, but I finally managed to do this via xorg.conf, like so:

jani@saegusa:~$ cat /etc/X11/xorg.conf.d/*
Section "Extensions"
 Option "DPMS" "Disable"
 Option "MIT-SCREEN-SAVER" "Disable"
EndSection

Section "Device"
   Identifier "Intel Graphics"
   Driver "intel"
   Option "DPMS" "Disable"
EndSection

Section "ServerFlags"
 Option "NoPM" "true"
EndSection

Section "ServerLayout"
 Identifier "X.org Configured"
 Option "BlankTime" "0"
        Option "StandbyTime" "0"
        Option "SuspendTime" "0"
        Option "OffTime" "0"
EndSection

It could be that just the ServerLayout section is actually required (and I'm not sure if other graphics drivers even have a DPMS option of their own like intel does), as none of the other sections by themselves nor together prevented the screen from turning off. (The most confusing one is MIT-SCREEN-SAVER, which I thought was exactly what the xset timeouts were controlling, but apparently not so, as disabling it does not prevent the issue either.)