Re: [PATCH] PCI PM: Restore standard config registers of all devices early (was: Re: EeePC resume failure - timers)

Rafael J. Wysocki
2009-01-16T21:11:56Z

On Friday 16 January 2009, Jesse Barnes wrote:
> On Friday, January 16, 2009 12:54 pm Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rjw@sisk.pl>
> > Subject: PCI PM: Restore standard config registers of all devices early
> >
> > There is a problem in our handling of suspend-resume of PCI devices
> > that many of them have their standard config registers restored with
> > interrupts enabled and they are put into the full power state with
> > interrupts enabled as well. This may lead to the following scenario:
> > * an interrupt vector is shared between two or more devices
> > * one device is resumed earlier and generates an interrupt
> > * the interrupt handler of another device tries to handle it and
> > attempts to access the device the config space of which hasn't
> > been restored yet and/or which still is in a low power state
> > * the system crashes as a result
> >
> > To prevent this from happening we should restore the standard
> > configuration registers of all devices with interrupts disabled and
> > we should put them into the D0 power state right after that.
> > Unfortunately, this cannot be done using the existing
> > pci_set_power_state(), because it can sleep. Also, to do it we have
> > to make sure that the config spaces of all devices were actually
> > saved during suspend.
> >
> > Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
>
> Thanks Rafael, I stuffed this one into my for-linus branch.

Thanks!

> I'd like it to go through a linux-next cycle before pushing it to Linus,

Me too.

> but if he's impatient to get it into -rc2 he can always pull sooner (there's
> only one other small fix in there atm).

Well, -rc2 is upon us already.

Thanks,
Rafael