linux-kernel - Re: [PATCH Resend] cpufreq: remove sysfs files for CPU which failed to come back after resume

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Message-ID: <871u14i00j.fsf@nemi.mork.no>
Date:	Mon, 23 Dec 2013 06:55:56 +0100
From:	Bjørn Mork <bjorn@...k.no>
To:	"Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:	Viresh Kumar <viresh.kumar@...aro.org>, cpufreq@...r.kernel.org,
	linux-pm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH Resend] cpufreq: remove sysfs files for CPU which failed to come back after resume

"Rafael J. Wysocki" <rjw@...ysocki.net> writes:

> Bjorn, can you please check if the pm-cpufreq branch of the linux-pm.git tree
> fixes the problem that you have reported 

I can confirm that it fixes the major regression.  With this branch, the
cpufreq directory is completely removed after a cancelled userspace
hibernate (with the acpi-cpufreq problem causing failure).  So it is
possible to restore cpufreq by manually offlining and onlining non-boot
cores.  No more leftover sysfs attributes.

But there is still a minor regression compared to the old (v3.11)
behaviour: Previously the cpufreq functionality would be automatically
restored by any completed hibernate or suspend cycle, since it would
effectively do the CPU offline/online. This automatix fixup won't happen
with the current pm-cpufreq branch.  User intervention is now required
to fix up cpufreq. Which is expected, due to the special handling of
cpufreq suspend.

So there is still a small, small regression here, making me believe that
my "fix" is better until the cpufreq suspend is properly fixed.  But
it's certainly not a major problem to me either way.  Your call.

> without causing any new breakage to happen?

I'm not going to guarantee that :-)  But I haven't noticed anything
obvious during the 15 minutes I've been testing this branch so far.

Bjørn
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