gnome-brightness-applet fails to change brightness

[t_e_r]

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

[penalvch (penalvch)]

t_e_r, this bug was reported a while ago and there hasn't been any activity in it recently. We were wondering if this is still an issue? If so, could you please test for this with the latest development release of Ubuntu? ISO images are available from http://cdimage.ubuntu.com/daily-live/current/ .

If it remains an issue, could you please run the following command in the development release from a Terminal (Applications->Accessories->Terminal), as it will automatically gather and attach updated debug information to this report:

apport-collect -p linux <replace-with-bug-number>

Also, could you please test the latest upstream kernel available following https://wiki.ubuntu.com/KernelMainlineBuilds ? It will allow additional upstream developers to examine the issue. Please do not test the daily folder, but the one all the way at the bottom. Once you've tested the upstream kernel, please comment on which kernel version specifically you tested. If this bug is fixed in the mainline kernel, please add the following tags:
kernel-fixed-upstream
kernel-fixed-upstream-VERSION-NUMBER

where VERSION-NUMBER is the version number of the kernel you tested. For example:
kernel-fixed-upstream-v3.11

This can be done by clicking on the yellow circle with a black pencil icon next to the word Tags located at the bottom of the bug description. As well, please remove the tag:
needs-upstream-testing

If the mainline kernel does not fix this bug, please add the following tags:
kernel-bug-exists-upstream
kernel-bug-exists-upstream-VERSION-NUMBER

As well, please remove the tag:
needs-upstream-testing

Once testing of the upstream kernel is complete, please mark this bug's Status as Confirmed. Please let us know your results. Thank you for your understanding.

[Launchpad Janitor (janitor)]

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