Okay, I just included some Debug statement into my DSDT.
Findings:

_OSI is not supported.

\_OS_ equals "Linux"

Follows:
Some sections in my DSDT (see attachment) are not executed on Linux.

This is the (decompiled and fixed) DSDT of an Acer TM630.

Isn't it a strange world where the BIOS is specific to an OS? And I
thought the OS should adapt to the hardware and not vice versa...