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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Fri, 18 Oct 2019 11:26:52 +0200
Message-ID: <CAJZ5v0hZc5g+AUDSJUkaGSA92mKNSXGyHLd5Qxuf88wP1i4AdA@mail.gmail.com>
Subject: Re: [RFT][PATCH 0/3] cpufreq / PM: QoS: Introduce frequency QoS and
 use it in cpufreq
To:     Viresh Kumar <viresh.kumar@linaro.org>
Cc:     "Rafael J. Wysocki" <rafael@kernel.org>,
        Sudeep Holla <sudeep.holla@arm.com>,
        "Rafael J. Wysocki" <rjw@rjwysocki.net>,
        Linux PM <linux-pm@vger.kernel.org>,
        Linux ACPI <linux-acpi@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Dmitry Osipenko <digetx@gmail.com>
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On Fri, Oct 18, 2019 at 11:24 AM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> On 18-10-19, 10:30, Rafael J. Wysocki wrote:
> > On Fri, Oct 18, 2019 at 10:27 AM Viresh Kumar <viresh.kumar@linaro.org> wrote:
> > >
> > > On 18-10-19, 10:24, Rafael J. Wysocki wrote:
> > > > On Fri, Oct 18, 2019 at 7:44 AM Viresh Kumar <viresh.kumar@linaro.org> wrote:
> > > > >
> > > > > On 17-10-19, 18:34, Rafael J. Wysocki wrote:
> > > > > > [BTW, Viresh, it looks like cpufreq_set_policy() should still ensure
> > > > > > that the new min is less than the new max, because the QoS doesn't do
> > > > > > that.]
> > > > >
> > > > > The ->verify() callback does that for us I believe.
> > > >
> > > > It does in practice AFAICS, but in theory it may assume the right
> > > > ordering between the min and the max and just test the boundaries, may
> > > > it not?
> > >
> > > I think cpufreq_verify_within_limits() gets called for sure from
> > > within ->verify() for all platforms
> >
> > That's why I mean by "in practice". :-)
>
> Hmm, I am not sure if we should really add another min <= max check in
> cpufreq_set_policy() as in practice it will never hit :)

Fair enough, but adding a comment regarding that in there would be prudent IMO.


>
> --
> viresh