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[Bug 283871] Re: gnome-brightness-applet fails to change brightness

 

[Expired for linux (Ubuntu) because there has been no activity for 60
days.]

** Changed in: linux (Ubuntu)
       Status: Incomplete => Expired

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https://bugs.launchpad.net/bugs/283871

Title:
  gnome-brightness-applet fails to change brightness

Status in “linux” package in Ubuntu:
  Expired

Bug description:
  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

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