[Nouveau] Acer Aspire V7-582PG (Haswell, GTX 750M) fails to power off GPU via Power Resources

[Zheng, Lv]

Hi, Mika

> From: Mika Westerberg [mailto:mika.westerberg at linux.intel.com]
> Subject: Re: Acer Aspire V7-582PG (Haswell, GTX 750M) fails to power off GPU via Power Resources
> 
> On Thu, Oct 27, 2016 at 06:06:48PM +0200, Peter Wu wrote:
> > On Thu, Oct 27, 2016 at 12:55:08PM +0300, Mika Westerberg wrote:
> > > On Thu, Oct 27, 2016 at 09:42:28AM +0000, Rick Kerkhof wrote:
> > > >    No, there are not. Here is the recursive directory listing:
> > >
> > > Are you able to try the following patch and send me dmesg (or attach it
> > > to that bug)? It should show if the ACPI core even tries to add those
> > > power resources.
> >
> > So Rick has tested this patch now on top of 4.8.4 (mainline fails to
> > boot due to a kbuild issue which I reported elsewhere), but the output
> > is empty. That seems to indicate that flags.power_resources is unset.
> 
> Is it completely empty or is it empty just for RP05? It should print out
> all devices with power resources.
> 
> > Given that _PS3 exists and is indeed a package with some elements, it
> > seems that acpi_extract_power_resources is failing. Note that in the
> > SSDT, the power resource NVP3 was referenced before it was defined,
> > could that result in this enumeration failure? Relevant SSDT excerpt:
> >
> >     Scope (\_SB.PCI0.RP05)
> >     {
> >         Name (_PR3, Package (0x01)  // _PR3: Power Resources for D3hot
> >         {
> >             NVP3
> >         })
> >         // ...
> >     }
> >
> >     PowerResource (NVP3, 0x00, 0x0000)

Looks wrong order to me.

However, _PR3 is a package, for AML opcode that contains PkgLength grammar primitive, forward reference may be OK (for example Method).
DefPackage := PackageOp PkgLength NumElements PackageElementList
DefMethod := MethodOp PkgLength NameString MethodFlags TermList
As when it is encountered, AML interpreter may only saves entire packaged object.

I need to test behaviors around Package with qemu but I don't have environment now.
Can you help to give it a try?
By adding customize an ssdt with the above code putting under root scope,
DefinitionBlock ("ssdt-package.aml", "SSDT", 2, "INTEL ", "PACKAGE ", 0x00003000)
{
    Scope (\)
    {
        Name (_PR3, Package (0x01) { NVP3 })
    }
    PowerResource (NVP3, 0x00, 0x0000) {}
}
Running Windows images on qemu with this ssdt appended "-acpitable file=ssdt-package.aml".
To see if blue screen can be resulted.

Thanks
Lv

> 
> That and the fact that they come from an SSDT instead of DSDT may cause
> this. However, I'm not expert in ACPICA so adding Bob and Lv if they
> have ideas.
> 
> Bob, Lv, the bug in question is: https://bugs.freedesktop.org/show_bug.cgi?id=98398