Arch Linux

roobre

Member

From: Spain

Registered: 2010-10-10

Posts: 34

How to *disable* or change behavior of brightness keys

Hi there!
I own a HP laptop with a dual Nvidia/Intel graphic card, with propietary drivers & bumblebee installed, and everything works perfect but brightness buttons.

In fact, they work, but not as they should. When I press the brightness up button, it raises, but it does it a lot. If I press it again, the brightness sets to its maximum value when the progress bar it shows is on ~20%

This is my theory of what's going on:
I have 3 folders on  `/sys/class/backlight`:

[root@Archpv3 backlight]# ls
acpi_video0  acpi_video1  intel_backlight

`acpi_video{0,1}` are, if not identical, equivalent: All the files inside them are equal. `intel_backlight` is different.
`acpi_video{0,1}/max_brightness` is 100. But, experimentally, I have ensured that the actual max_brightness of my screen is 20.

My theory is that, the thing listening on brightness buttons (and not, its not acpid), gets the maximum value from `acpi_video{0,1}/max_brightness`, and when I press a brighness button, it raises it to `acpi_video{0,1}/max_brightness`/10.
There may be three solutions to this: Change the `max_brightness` to 20 by machete, or change the step by machete too. Other solution will be to tell the thing I want it to use `intel_backlight`.

I dont' know how to do anyone of these because I still don't know what the hell is listening that events :\
So, finally, and sorry for such a big intro, does anyone knows?

Regards, and thanks in advance ^^

EDIT: I though backticks ` will make the in-line code effect, but they didn't. Sorry if they annoy you xD

Last edited by roobre (2013-06-21 16:08:52)