linux-kernel - Re: [PATCH V5] PM / OPP: Pass opp_table to dev_pm_opp_put

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Message-ID: <20161201002548.GO3288@vireshk-i7>
Date:   Thu, 1 Dec 2016 05:55:48 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Stephen Boyd <sboyd@...eaurora.org>
Cc:     Rafael Wysocki <rjw@...ysocki.net>, jy0922.shim@...sung.com,
        Viresh Kumar <vireshk@...nel.org>, Nishanth Menon <nm@...com>,
        linaro-kernel@...ts.linaro.org, linux-pm@...r.kernel.org,
        linux-kernel@...r.kernel.org,
        Vincent Guittot <vincent.guittot@...aro.org>,
        "# v4 . 4+" <stable@...r.kernel.org>
Subject: Re: [PATCH V5] PM / OPP: Pass opp_table to dev_pm_opp_put_regulator()

On 30-11-16, 14:00, Stephen Boyd wrote:
> On 11/30, Viresh Kumar wrote:
> > From: Stephen Boyd <sboyd@...eaurora.org>
> > 
> > Joonyoung Shim reported an interesting problem on his ARM octa-core
> > Odoroid-XU3 platform. During system suspend, dev_pm_opp_put_regulator()
> > was failing for a struct device for which dev_pm_opp_set_regulator() is
> > called earlier.
> > 
> > This happened because an earlier call to
> > dev_pm_opp_of_cpumask_remove_table() function (from cpufreq-dt.c file)
> > removed all the entries from opp_table->dev_list apart from the last CPU
> > device in the cpumask of CPUs sharing the OPP.
> > 
> > But both dev_pm_opp_set_regulator() and dev_pm_opp_put_regulator()
> > routines get CPU device for the first CPU in the cpumask. And so the OPP
> > core failed to find the OPP table for the struct device.
> > 
> > This patch attempts to fix this problem by returning a pointer to the
> > opp_table from dev_pm_opp_set_regulator() and using that as the
> > parameter to dev_pm_opp_put_regulator(). This ensures that the
> > dev_pm_opp_put_regulator() doesn't fail to find the opp table.
> > 
> > Note that similar design problem also exists with other
> > dev_pm_opp_put_*() APIs, but those aren't used currently by anyone and
> > so we don't need to update them for now.
> > 
> > [Viresh]: Written commit log and tested on exynos 5250.
> > 
> > Cc: # v4.4+ <stable@...r.kernel.org>
> > Reported-by: Joonyoung Shim <jy0922.shim@...sung.com>
> > Signed-off-by: Stephen Boyd <sboyd@...eaurora.org>
> > Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
> > ---
> 
> You should have asked for my Signed-off-by instead of just adding
> it.

I was worried about the 24 hrs that gets wasted because of 12 hrs
difference in our time zones and so added you as the author and added
your sob. :)

> Here it is to make things explicit and recorded:

Thanks.

-- 
viresh