Hello,
I have an asus P31SD laptop. It has two LCD brightness modules which can control LCD backlight asus-nb-wmi and intel_brightness. Problem is that Fn+F5 and Fn+F6 keys control LCD brightness using asus-nb-wmi module and kde power management uses intel_brightness to control it. That results in the problem that brightness set up by Fn keys is not reflected in the power management settings and every time I click on the battery icon in the system notification area the brightness pops to the level set up by the slider in the tooltip.

1. Is it possible to tell kde power management which backlight module to use to avoid this inconsistent and annoying behavior?

2. Is there a way to disable and enable power management trough a script using dbus or something smilar? It should disable complete kde power management and screensaver just like it is done when the checkbox enable power management in the tooltip of the notification area power management icon is unchecked.

As far as I am aware, there is no configuration to control which backlight module is used.

The first question I have is why there is two backlight modules - there should only be one in use for a given display.

The "Enable Power Management" checkbox causes a D-Bus call to be made I believe...

Quick thought... try adding acpi_backlight=vendor to the kernel boot parameters in /etc/default/grub. Do you know how to do this, or do you need step-by-step instructions?

Thanks for the replies!
I have already set acpi_backlight=vendor option in my grub. I have also already tried to put acpi_backlight=video but still both backlight modules are active. Is there a way to disable one of the modules I have searched for intel_brightness module via lsmod but I can't find any module named like that.

On my ThinkPad X1 with Intel HD 3000 graphics, intel_backlight is created in /sys/class/backlight by the i915 driver module.

I Googled around a bit and found a couple things that might be of interest...

http://hircus.wordpress.com/2011/07/14/ ... t-control/
https://gist.github.com/1082058

Not having an Asus, I can't offer a prediction of expected behavior, but perhaps these will lead you closer to a solution.