Re: PCI PM: Restore standard config registers of all devices early

Rafael J. Wysocki
2009-02-02T22:34:19Z

On Monday 02 February 2009, Linus Torvalds wrote:
>
> On Mon, 2 Feb 2009, Rafael J. Wysocki wrote:
> >
> > I think it would be easier to make ACPI allow us to run AML with interrupts
> > off.
>
> Well, I'd agree, except I have this strong memory of us having known bugs
> with ACPI turning hard-interrupts on again. Similarly, it uses mutexes etc
> that simply don't work with interrupts off and/or may turn them on again
> thanks to scheduling.
>
> "Fixing" that seems not very easy. ACPI has a bad habit of being _really_
> hard to fix in this area.
>
> I do agree that _if_ we can just fix ACPI, we wouldn't have these issues,
> and we should just call it with interrupts disabled with our existing
> code. But my previous email was a "maybe we can do it like this" kind of
> thing, which might allow us to use ACPI with none of the irq-off issues.

Well, I think both will be difficult, this way or another. :-)

I'll have a look at the ACPI thing.

Thanks,
Rafael