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

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Message-ID: <af5d30f36092f387e4de7e4c09ca09f9de0478ba.camel@mediatek.com>
Date:   Wed, 4 May 2022 20:06:38 +0800
From:   Rex-BC Chen <rex-bc.chen@...iatek.com>
To:     Viresh Kumar <viresh.kumar@...aro.org>,
        Rafael Wysocki <rjw@...ysocki.net>,
        "Rafael J. Wysocki" <rafael@...nel.org>,
        "Matthias Brugger" <matthias.bgg@...il.com>
CC:     <linux-pm@...r.kernel.org>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        <linux-kernel@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-mediatek@...ts.infradead.org>, <jia-wei.chang@...iatek.com>
Subject: Re: [PATCH] cpufreq: Avoid unnecessary frequency updates due to
 mismatch

On Wed, 2022-05-04 at 13:51 +0530, Viresh Kumar wrote:
> For some platforms, the frequency returned by hardware may be
> slightly
> different from what is provided in the frequency table. For example,
> hardware may return 499 MHz instead of 500 MHz. In such cases it is
> better to avoid getting into unnecessary frequency updates, as we may
> end up switching policy->cur between the two and sending unnecessary
> pre/post update notifications, etc.
> 
> This patch has chosen allows the hardware frequency and table
> frequency
> to deviate by 1 MHz for now, we may want to increase it a bit later
> on
> if someone still complains.
> 
> Reported-by: Rex-BC Chen <rex-bc.chen@...iatek.com>
> Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
> ---
> 

Hello Viresh,

Thanks for your help!
Jia-wei verified this patch in his device, and I help him to add this.

Tested-by: Jia-wei Chang <jia-wei.chang@...iatek.com>

BRs,
Rex