Arch Linux

archtnoo

Member

Registered: 2008-12-03

Posts: 9

Backlight problems with 2.6.28

Hi there

After upgrading to 2.6.28 I was thrilled to see that panasonic-laptop is now in the kernel. However all the old scripts to change backlight brightness (from the pcc-acpi Panasonic package) don't work anymore. Not too surprising I think, but how can get backlight brightness functionality again?

Hardware: Panasonic Let's Note CF-W4, Intel Mobile 915GM/GMS/910GML

Here some more specific questions that somebody might know the answer to. I could not find any documentation on how to use the new acpi infrastructure from userspace.

o why does xbacklight nothing?
o what is /proc/acpi/video/GFX0/LCD1/brightness good for? Neither can I get a value, nor set any? All I get is
  <not supported>?
o which acpi event changes screen brightness?
o which acpi event changes sound volume?
o does anybody know how to use the panasonic-laptop kernel module functionality?

Thanks for any enlightenment!

Best, tnoo

archtnoo

Member

Registered: 2008-12-03

Posts: 9

Re: Backlight problems with 2.6.28

o why does xbacklight nothing?

This is actually not true:
xbacklight -set 100

sets screen brightness to 100% using the xrandr extension. However the brightness seems less than before.

Any hints for the other quetsions?