linux-kernel - Re: [PATCH] cpufreq: Avoid unnecessary frequency updates due to mismatch

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Date:   Thu, 5 May 2022 13:58:01 +0530
From:   Viresh Kumar <viresh.kumar@...aro.org>
To:     Vincent Guittot <vincent.guittot@...aro.org>
Cc:     Rafael Wysocki <rjw@...ysocki.net>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        Matthias Brugger <matthias.bgg@...il.com>,
        linux-pm@...r.kernel.org, Rex-BC Chen <rex-bc.chen@...iatek.com>,
        linux-kernel@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
        linux-mediatek@...ts.infradead.org
Subject: Re: [PATCH] cpufreq: Avoid unnecessary frequency updates due to
 mismatch

On 05-05-22, 10:21, Vincent Guittot wrote:
> Part of your problem is that cpufreq use khz whereas clock uses hz

Not in this case at least as the value mentioned in OPP table DT is in
Hz.

> Would it be better to do something like below in cpufreq_generic_get
> 
> (clk_get_rate(policy->clk) + 500) / 1000
> 
> so you round to closest instead of always floor rounding

That would be a fine thing to do anyway, though I am not sure if it
will fix the problem at hand.

If the hardware returns 499,999,499 Hz, we will still have the
problem.

-- 
viresh