From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Gleixner <tglx@linutronix.de>
Subject: Re: kerneloops.org report for the week of June 14 2009
Date: Tue, 23 Jun 2009 18:58:43 +0200 (CEST)
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References: <20090614173331.18f01123@infradead.org> <alpine.LFD.2.00.0906231201430.2767@localhost.localdomain> <20090623115510.GC9497@elte.hu> <200906231856.24959.rjw@sisk.pl>
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To: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Ingo Molnar <mingo@elte.hu>, Peter Zijlstra <a.p.zijlstra@chello.nl>, Arjan van de Ven <arjan@infradead.org>, LKML <linux-kernel@vger.kernel.org>, Linus Torvalds <torvalds@linux-foundation.org>, Andrew Morton <akpm@linux-foundation.org>, Venki Pallipadi <venkatesh.pallipadi@intel.com>, Len Brown <lenb@kernel.org>, Benjamin Herrenschmidt <benh@kernel.crashing.org>, ACPI Devel Maling List <linux-acpi@vger.kernel.org>

On Tue, 23 Jun 2009, Rafael J. Wysocki wrote:
> The long term solution for the issue at hand is to clean up the suspend-resume
> support in cpufreq so that it doesn't do stupid things like calling
> smp_call_function_single() with interrupts disabled, but that requires someone
> (I can do it, but I need to dig through the cpufreq code for this purpose) to
> figure out how to fix it.
> 
> I'm not quite sure if there's an acceptable short term solution, though.
> 
> In principle we can do
> 
> local_irq_save()
> ...
> local_irq_restore()
> 
> around each sysdevs ->susend() and ->resume() in addition to checking the
> status of interrupts.  Would that work?

Well not really, if the function enables interrupts you run into the
same issue (interrupt service routine calls ktime_get()) again.

Thanks,

	tglx