Brightness not auto-adjusting anymore when switched from AC to battery

.:B:. · 2008-01-13 23:54:28

I have a 6510b recently purchased, running Arch from the beginning. Everything I need works fine. Normally, when I unplug the power cord, the laptop starts using the battery and automatically dims the screen (the backlight). Since a few days that is no longer the case. I have not touched any of the ACPI settings, nor did i touch the BIOS settings (the brightness adjustment worked out of the box - automagically, if you wish). I have checked pacman's log to see if any related packages got an upgrade - nope. I am puzzled as to what could be the problem here - the ACPI log clearly shows the daemon detects the unplugging of the power cord, it clearly reports ac_adapter and battery events...

I am still able to manually adjust the brightness as I was before (using Fn + F9/F10). When using those shortcuts I see the brightness change, and the corresponding sysfs entry (/sys/class/backlight/acpi_video0/actual_brightness) also changes. However, I seem unable to change this entry directly (by using echo $number > $sysfs_entry). I already tried to work around the 'problem' by editing the ACPI handler script to run either those echo commands (which do not work) or an xbackground command (which works for a while but then mysteriously ceases to function), but after restarting the ACPI daemon or rebooting, that does not have any effect at all.

I was wondering if other 6510b owners are experiencing the same problem? I recently changed GUIs - swapped Xfce for Openbox - but I tried my old Xfce install and it exhibited exactly the same problem. This is some low-level stuff, so I don't think the software you run on top shouldn't matter either...

Last edited by B (2008-01-13 23:56:04)

.:B:. · 2008-01-15 09:31:13

* Bump *

I replaced hal-info 20071212 by hal-info 20071031 yesterday, hoping that would fix it (the hal-info package was upgraded a few days ago and since hal has a backlight interface I thought it could be involved). No luck though...

.:B:. · 2008-01-16 16:09:10

Here we go again

Arch Linux

#1 2008-01-13 23:54:28

Brightness not auto-adjusting anymore when switched from AC to battery

#2 2008-01-15 09:31:13

Re: Brightness not auto-adjusting anymore when switched from AC to battery

#3 2008-01-16 16:09:10

Re: Brightness not auto-adjusting anymore when switched from AC to battery

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