Re: Thinkpad R61i : Brightness Problem with Fn keys

[Florian Reitmeir <florian@reitmeir.org>]

On Fri, 22 Aug 2008, umesh debian wrote:

> I have installed Debian Lenny on my machine(Thinkpad R61i). I am using
> custom kernel 2.6.25.6 with changes for USB modems.
> The ALSA sound module is working fine and the Volume keys are working
> with the GUI indication(volume is going up and down).

> But the Brightness keys (Fn+Pgup or Pgdwn) are not working fine. The
> GUI indication is happening but the Brightness is neither going down
> nor up.

thats ok

> But if in ROOT console i manipulate brightness through the proc file
> system, then brightness is getting changed.
>
> This brings down brightness
> echo 4 > /proc/acpi/ibm/cmos
>
> This brings up brightness
> echo 5 > /proc/acpi/ibm/cmos
>
> During this too i am getting the GUI indication from the tpb module.
>
> Any suggestions on how to debug this?? I am using KDE 3.5.9

you have some players here..

first the "thinkpad_acpi" kernel module
   - it handles all your special buttons
   - it has tweaks for varios old configs like the /proc interface
   - it allows to modify how the buttons should work

old model:
   - the kernel did nothing
   - the userspace polled with tools like tpd the state and changed it
   - not a good solution

new model:
   - the kernel handels everything
   - userspace has to tell the kernel how it should be done
   
   here is your problem. the thinkpad_acpi module per default doesn't
handle brightness, because the newer X servers in combination with hal
should do it.


so take a look at 
http://git.kernel.org/?p=linux/kernel/git/stable/linux-2.6.26.y.git;a=blob_plain;f=Documentation/laptops/thinkpad-acpi.txt;hb=HEAD
Line: 534, Compatibility notes

--
Florian Reitmeir