[lucid regression] laptop thinks it is running on battery after resume from suspend to RAM

[Per Ångström]

Binary package hint: gnome-power-manager

I am having trouble after resuming from suspend to RAM on one of my laptops. This is on Lucid - it used to work perfectly on Jaunty.

This bug, which is a spin-off from bug #510004, concerns the power manager: after resume from suspend it seems to think that the laptop is now running on battery power, so it dims the screen, even though the machine is still connected to the mains.

This is reproducible on one of my laptop machines. On the second one, I have not observed this behavior.

How to reproduce:
0) Make sure you are logged in to Gnome.
1) Make sure your computer is connected to the mains.
2) Suspend to RAM.
3) Resume.

Expected behavior: The display should retain the same brightness level as before.
Actual behavior: The display is dimmed.

ProblemType: Bug
Architecture: amd64
Date: Wed Jan 20 15:06:03 2010
DistroRelease: Ubuntu 10.04
EcryptfsInUse: Yes
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
NonfreeKernelModules: nvidia
Package: gnome-power-manager 2.29.1-0ubuntu1
ProcVersionSignature: Ubuntu 2.6.32-11.15-generic
SourcePackage: gnome-power-manager
Tags: lucid
Uname: Linux 2.6.32-11-generic x86_64

[Per Ångström (autark)]

Attaching output of gnome-power-manager, as per instructions in bug #510004, comment #5.
> 1. Kill gnome-power-manager (command: killall gnome-power-manager)
> 2. Run `gnome-power-manager --verbose` in a terminal, suspend and resume

[Per Ångström (autark)]

I'm only seeing this on either of my two laptops. This makes me think it's a lower-level issue. Tentatively assigning to acpid package.

[Per Ångström (autark)]

No improvement with kernel 2.6.32-12-generic.

[Per Ångström (autark)]

Reassigning to gnome-power-manager. The dimming of the screen does not occur when I run KDE.

[Per Ångström (autark)]

I have updated the bug description to remove all mention of the battery icon.

[Per Ångström (autark)]

No improvement with gnome-power-manager 2.29.2-0ubuntu1.