Re: [PATCH v4] pci: prevent putting nvidia GPUs into lower device states on certain intel bridges

[Karol Herbst]

On Wed, Nov 27, 2019 at 12:49 PM Mika Westerberg
<mika.westerberg@xxxxxxxxx> wrote:
>
> On Tue, Nov 26, 2019 at 06:10:36PM -0500, Lyude Paul wrote:
> > Hey-this is almost certainly not the right place in this thread to respond,
> > but this thread has gotten so deep evolution can't push the subject further to
> > the right, heh. So I'll just respond here.
>
> :)
>
> > I've been following this and helping out Karol with testing here and there.
> > They had me test Bjorn's PCI branch on the X1 Extreme 2nd generation, which
> > has a turing GPU and 8086:1901 PCI bridge.
> >
> > I was about to say "the patch fixed things, hooray!" but it seems that after
> > trying runtime suspend/resume a couple times things fall apart again:
>
> You mean $subject patch, no?
>

no, I told Lyude to test the pci/pm branch as the runpm errors we saw
on that machine looked different. Some BAR error the GPU reported
after it got resumed, so I was wondering if the delays were helping
with that. But after some cycles it still caused the same issue, that
the GPU disappeared. Later testing also showed that my patch also
didn't seem to help with this error sadly :/

> > [  686.883247] nouveau 0000:01:00.0: DRM: suspending object tree...
> > [  752.866484] ACPI Error: Aborting method \_SB.PCI0.PEG0.PEGP.NVPO due to previous error (AE_AML_LOOP_TIMEOUT) (20190816/psparse-529)
> > [  752.866508] ACPI Error: Aborting method \_SB.PCI0.PGON due to previous error (AE_AML_LOOP_TIMEOUT) (20190816/psparse-529)
> > [  752.866521] ACPI Error: Aborting method \_SB.PCI0.PEG0.PG00._ON due to previous error (AE_AML_LOOP_TIMEOUT) (20190816/psparse-529)
>
> This is probably the culprit. The same AML code fails to properly turn
> on the device.
>
> Is acpidump from this system available somewhere?
>