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

["Rafael J. Wysocki" <rjw@sisk.pl>]

On Friday, August 05, 2011, Rafael J. Wysocki wrote:
> On Friday, August 05, 2011, Alan Stern wrote:
> > 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.
> 
> You're right, sorry.  System suspend was not involved, so the problem
> was triggerend by runtime suspend alone, resulting from unplugging the
> Ethernet cable.
> 
> It looks like the crash started in pci_disable_msi().

OTOH, I'm not sure how pci_legacy_suspend_late() was called.
In theory it is only called by the system suspend code and it surely
is not called for e1000e.

Thanks,
Rafael