Re: [PATCH] ACPI / PM: Hold acpi_scan_lock over system PM transitions

From: Rafael J. Wysocki
Date: Tue Aug 20 2013 - 08:14:14 EST


On Tuesday, August 20, 2013 02:08:33 PM Mika Westerberg wrote:
> On Tue, Aug 20, 2013 at 01:47:57AM +0200, Rafael J. Wysocki wrote:
> > From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
> >
> > Bad things happen if ACPI hotplug events are handled during system
> > PM transitions, especially if devices are removed as a result.
> > To prevent those bad things from happening, acquire acpi_scan_lock
> > when a transition is started and release it when that transition
> > is complete or has been aborted.
> >
> > This fixes resume lockup on my test-bed Acer Aspire S5 that happens
> > when Thunderbolt devices are disconnected from the machine while
> > suspended.
> >
> > Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
>
> I tested this on Intel DZ77RE-75K and after the patch is applied the
> machine didn't hang anymore once resuming.
>
> Feel free to add my tested-by.

I will, thanks!

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