hybrid-graphics-linux team mailing list archive

[Lekensteyn <lekensteyn@xxxxxxxxx>]

Hi all,

I'd like to know what the current knowledge level is on desktops with
Synergy switching
technology. It is a solution for desktops which is called Optimus on
laptops. I first
encountered it with
https://bugs.launchpad.net/lpbugreporter/+bug/752542/comments/466

These machines have the same _DSM UUID and function that is found on Optimus
machines. This calls a NVOP function which is found on some machines as
well. This
Optimus UUID needs the next sequence on Optimus laptops for turning the
device off:

- _DSM ...
- _PS3
After that, the PCI configuration space cannot be read anymore because the
device is off
(yielding all bits enabled, ff ff ff ...)

On the desktop I've analyzed, this did not happen.

# modprobe bbswitch
Jan 12 01:05:40 vostro360 kernel: [ 1796.494370] bbswitch: Found discrete
VGA device 0000:01:00.0: \_SB_.PCI0.P0P1.VGA_
Jan 12 01:05:40 vostro360 kernel: [ 1796.494845] bbswitch: detected an
Optimus _DSM function
Jan 12 01:05:40 vostro360 kernel: [ 1796.494853] bbswitch: Succesfully
loaded. Discrete card 0000:01:00.0 is on

# tee /proc/acpi/bbswitch <<<OFF
Jan 12 01:07:06 vostro360 kernel: [ 1882.279130] bbswitch: disabling
discrete graphics
Jan 12 01:07:06 vostro360 kernel: [ 1882.279622] bbswitch: Result of
Optimus _DSM call: 00000019
Jan 12 01:07:06 vostro360 kernel: [ 1882.299240] pci 0000:01:00.0: Refused
to change power state, currently in D0
Jan 12 01:07:06 vostro360 kernel: [ 1882.299276] pci 0000:01:00.0: power
state changed by ACPI to D3

$ cat /proc/acpi/bbswitch
0000:01:00.0 ON

# tee /proc/acpi/bbswitch <<<OFF
Jan 12 01:07:15 vostro360 kernel: [ 1891.686455] bbswitch: disabling
discrete graphics
Jan 12 01:07:15 vostro360 kernel: [ 1891.686923] bbswitch: Result of
Optimus _DSM call: 00000019
Jan 12 01:07:15 vostro360 kernel: [ 1891.697091] pci 0000:01:00.0: power
state changed by ACPI to D3

$ cat /proc/acpi/bbswitch
0000:01:00.0 ON


If you have a Synergy machine, please submit your machine on
https://bugs.launchpad.net/lpbugreporter/+bug/752542. If you've knowledge,
please share it :)

Regards,
Lekensteyn