hybrid-graphics-linux team mailing list archive

[George Shearer <george@xxxxxxxxxxxxxxxxxxxx>]

All,

  I've been tinkering with my Alienware M11X R2, trying to figure out what
ACPI methods to call (and how) to shut off the nVidia GPU. I finally figured
it out how to do just that.

  First off, the relevant ACPI methods are contained in an SSDT. A method
called NVOP must be called first, followed by _PS3.

  NVOP requires four arguments:

  1. This doesn't appear to be used for anything, but I send integer 0.
  2. This must be integer 0x0100
  3. This must be integer 0x1A
  4. This must be acpi_object type 'buffer', and it appears to require 26
bytes, but I send 32. I set all bits to 1 (255,255,255,255).

  If _PS3 is called with no arguments immediately following, my power usage
drops from 17000 mW to about 12000 mW. Also noticed that my laptop runs
cooler.

  I hacked the original acpi_call.c to do this, but it's currently very ugly
:) I'm going to do more tinkering to see if I can manage to turn the GPU on
and actually use it.  When I get time, I'll try to make a new kernel module
for controlling this. It could probably be used for other laptops with
slight modifications.

  Has Nvidia released any documentation on their ACPI facilities? That'd be
really helpful. More information:
http://forums.fedoraforum.org/showthread.php?t=248837&highlight=alienware

-G