Re: [linux-pm] Crash when suspending Lenovo T510 laptop (2.6.39.3)

From: Alan Stern
Date: Fri Aug 05 2011 - 16:21:45 EST


On Fri, 5 Aug 2011, Rafael J. Wysocki wrote:

> > > I don't know how to fix it yet, but I think I know what the problem is.
> > > Namely, a runtime suspend of the Ethernet adapter as occured in parallel with
> > > the system-wide suspend and they clashed. The runtime suspend has probably
> > > been provoked by detaching the Ethernet cable from the box.
> >
> > For them to clash in that way would mean that the PM workqueue didn't
> > get frozen.
>
> Not necessarily, I think. It's sufficient that system suspend is started
> while the runtime PM operation is in progress.

How so? The system suspend doesn't call down to the subsystems or
drivers until after all the threads are frozen. In this case the stack
dump shows that the runtime PM operation was asynchronous, running in a
workqueue thread (pm_runtime_work is one of the routines near the end
of the stack dump). The thread wouldn't have frozen until the runtime
PM operation was complete.

Alan Stern

--
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/