Re: [PATCH] Quirk to fix suspend/resume on Lenovo Edge 11,13,14,15

[Thomas Gleixner]

On Thu, 13 Jan 2011, Borislav Petkov wrote:

> On Thu, Jan 13, 2011 at 08:13:42PM +0100, Thomas Gleixner wrote:
> > > Well, Andreas did boot with 'hpet=verbose' on an affected machine here
> > > and did a suspend/resume and the hpet config registers looked ok before
> > > suspend and after resume. It might be that the HPET is temporarily
> > > "insane" while resume lasts but we don't have any hard facts confirming
> > 
> > And you have no explanation at all why applying the irq pin routing
> > quirk makes HPETs temporal insanity go away magically :)
> 
> But after the HPET counter wraps around, the machine is alive again.
> Which means that the IRQ0 pin2 override is only temporarily needed after
> resume... Strange.

Thinking more about it:

Case 1:	IRQ0 pin2 override applied

     Resume hangs until HPET wraps around and issues another interrupt

Case 2: IRQ0 pin2 override ignored via quirk

     Resume just works

So the question is what is restored _AFTER_ the HPET is reprogrammed
in the resume path ?

The HPET reprogramming happens via timekeeping_resume() which is in
the sysdev part of resume. ioapic, apic, iommus etc. are also resumed
via the sysdev_class. So what makes sure that the ordering of these is
correct?

AFAICT nothing :)

We need information about the resume order of sysdev_class and the
difference of the pin routings in the quirk non/quirk case.

Thanks,

	tglx
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/