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Binary package hint: gnome-power-manager

I am using ubuntu-bug in Intrepid beta (upgraded to most recent). I hope
all the deep details are being automatically reported. ubuntu-bug was
called right after the applet failed to change the brightness after the
slider had been moved.

I want to append this report to Bug #222171, "[Hardy] Backlight low on
Asus x57 laptop (M50sa)" as a response to a request by
https://bugs.launchpad.net/~leannogasawara there to check this problem
against the then new Intrepid versions of the kernel. The kernel is now
beyond the version mentioned in the request. The problem persists.
However, the bug tracker did not offer the above bug to be added to.

The Intrepid install is into an Asus M70vm. This machine has a light
sensor, as do all of the machines reported in  Bug #222171, I believe.

Here's my take on the problem. The kernel driver that controls the
backlight has two variables in /sys/devices/platform/asus-laptop/,
ls_switch and ls_level. Even though ls_switch is presumed to turn OFF
the light sensor, it in fact turns all control of the backlight. So
ls_switch must be left at a value of 1. ls_level sets the floor to the
brightnes, and is initialized to 0. The brightness control FN keys do
not work, and so the user is literally left in the dark towards the end
of a day when the brightness drops to the floor of 0.

The gnome applet gives two error conditions upon attempts to set the brightness 
1) unable to read the brightness (no exact words)
2) cannot connect to gnome-power-manager

This asus comes with their "express gate" OS, which I understand is
Gnu/Linux. In "express gate", the light sensor is overriden, and all FN
keys work. I wonder why their driver has not been contributed back to
Gnu/Linux, and why there is no information offered as to how to find
information about either their driver or hardware information.


My crude workaround is to chmod go+w at end of boot, because the files in /sys/devices/platform/asus-laptop/ are re-created afresh on each boot. Then set up custom launches on the gnome to set the higher levels.

ProblemType: Bug
Architecture: amd64
DistroRelease: Ubuntu 8.10
ExecutablePath: /usr/lib/gnome-power-manager/gnome-brightness-applet
NonfreeKernelModules: nvidia
Package: gnome-power-manager 2.24.0-0ubuntu4
ProcEnviron:
 LANG=en_US.UTF-8
 PATH=/home/username/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin:/usr/games
 SHELL=/bin/bash
SourcePackage: gnome-power-manager
Uname: Linux 2.6.27-7-generic x86_64

** Affects: linux (Ubuntu)
     Importance: Undecided
         Status: Incomplete


** Tags: applet apport-bug brightness gnome manager power
-- 
gnome-brightness-applet fails to change brightness
https://bugs.launchpad.net/bugs/283871
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