linux-kernel - Re: [PATCH] cpufreq: Report if CPU doesn't report boost technologies

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Date:   Wed, 20 Feb 2019 11:41:11 +0100
From:   "Rafael J. Wysocki" <rafael@...nel.org>
To:     Erwan Velu <erwanaliasr1@...il.com>
Cc:     Erwan Velu <e.velu@...teo.com>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        "open list:CPU FREQUENCY SCALING FRAMEWORK" 
        <linux-pm@...r.kernel.org>,
        open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] cpufreq: Report if CPU doesn't report boost technologies

On Wed, Feb 20, 2019 at 11:11 AM Erwan Velu <erwanaliasr1@...il.com> wrote:
>
> There is some rare cases where CPB (and possibly IDA) are missing on processors.
> This is the case fixed by commit f7f3dc00f612 ("x86/cpu/AMD: Fix erratum 1076 (CPB bit)") and following.
>
> In such context, the boost status isn't reported by /sys/devices/system/cpu/cpufreq/boost.

So I'm not really sure why the extra message is needed.  It looks like
this message will always be printed (with debug output enabled) if the
current cpufreq driver is acpi-cpufreq and the boost attribute is not
present in sysfs, which only is the case if CPB/IDA aren't there.

Does it provide any additional information, then?