amd64/181357: LCD Brightness Control not working on Lenovo X121e (ACPI issue?)

[Matthias Petermann]

Am 24.08.2013 20:02, schrieb Dominic Fandrey:
> My LCD brightness control stopped working when I switched to NEW_XORG 
> with Intel KMS (on stable/9). 

It's the same issue when I run in console only mode (without Xorg, 
without KMS kernel module loaded).
What Lenovo model are you using?