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Date: Thu, 17 Jul 2014 11:05:14 +0530
Message-ID: <CAKohpongsNtEVbHL=w1fbw5tEXK=WaMcp1N03ar9Sx_CU=1O-w@mail.gmail.com>
Subject: Re: [PATCH v3 1/2] cpufreq: Don't destroy/realloc policy/sysfs on hotplug/suspend
From: Viresh Kumar <viresh.kumar@linaro.org>
To: Saravana Kannan <skannan@codeaurora.org>
Cc: "Srivatsa S. Bhat" <srivatsa@mit.edu>,
        "Rafael J . Wysocki" <rjw@rjwysocki.net>,
        Todd Poynor <toddpoynor@google.com>,
        "linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        "linux-arm-msm@vger.kernel.org" <linux-arm-msm@vger.kernel.org>,
        "linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
        Stephen Boyd <sboyd@codeaurora.org>
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On 17 July 2014 01:26, Saravana Kannan <skannan@codeaurora.org> wrote:
> On 07/16/2014 04:16 AM, Srivatsa S. Bhat wrote:

>> That is, we wanted
>> to do the kobject cleanup after releasing the hotplug lock, and POST_DEAD
>> stage was well-suited for that.

I think, this has changed in Saravana's patch, we do it in the PREPARE stage
now.

>> Commit 1aee40ac9c8 (cpufreq: Invoke __cpufreq_remove_dev_finish() after
>> releasing cpu_hotplug.lock) explains this in detail. Saravana, please take
>> a
>> look at that reasoning and ensure that your patch doesn't re-introduce
>> those
>> deadlock possibilities!
>
>
> But all of that was needed _because_ we were creating and destroying
> policies and kobjs all the time. We don't do that anymore. So, I don't think
> any of that applies. We only destroy when the cpufreq driver is
> unregistered. That's kinda of the point of this patchset.
>
> Thoughts?

See above.