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Date:   Thu, 14 Feb 2019 08:59:47 -0800
From:   Matthias Kaehlcke <mka@chromium.org>
To:     Chanwoo Choi <cwchoi00@gmail.com>
Cc:     MyungJoo Ham <myungjoo.ham@samsung.com>,
        Kyungmin Park <kyungmin.park@samsung.com>,
        Chanwoo Choi <cw00.choi@samsung.com>,
        Thierry Reding <thierry.reding@gmail.com>,
        Jonathan Hunter <jonathanh@nvidia.com>,
        Linux PM list <linux-pm@vger.kernel.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        linux-tegra@vger.kernel.org,
        Lukasz Luba <l.luba@partner.samsung.com>
Subject: Re: [PATCH 1/4] PM / devfreq: Track overall load monitor state
 instead of 'stop_polling'
Message-ID: <20190214165947.GY117604@google.com>
References: <20190214013042.254790-1-mka@chromium.org>
 <20190214013042.254790-2-mka@chromium.org>
 <CAGTfZH3E+RetMzKxzZNEgYw6=kocdfgRcKSbmP5GfZ4k1j0Cuw@mail.gmail.com>
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Hi Chanwoo,

On Thu, Feb 14, 2019 at 11:25:52PM +0900, Chanwoo Choi wrote:
> Hi Matthias,
> 
> 2019년 2월 14일 (목) 오후 7:16, Matthias Kaehlcke <mka@chromium.org>님이 작성:
> >
> > The field ->stop_polling indicates whether load monitoring should be/is
> > stopped, it is set in devfreq_monitor_suspend(). Change the variable to
> > hold the general state of load monitoring (stopped, running, suspended).
> > Besides improving readability of conditions involving the field and this
> > prepares the terrain for moving some duplicated code from the governors
> > into the devfreq core.
> >
> > Hold the devfreq lock in devfreq_monitor_start/stop() to ensure proper
> > synchronization.
> 
> IMHO, I'm not sure that there are any benefits changing
> from 'stop_polling' to 'monitor_state'. I have no objections
> if Myungjoo confirms it.

I agree that as an isolated change there isn't a clear benefit.
However in the context of the series the change is needed to
avoid resuming a load monitor that wasn't even started.

In case this series isn't accepted I'd still suggest to change the
name from 'stop_polling' to 'suspended'. I read 'stop_polling' as a
call for action, while 'suspended' is a state. IMO at least in some
contexts conditions using a state is clearer.

Cheers

Matthias