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From:   Pratyush Yadav <ptyadav@amazon.de>
To:     "Rafael J. Wysocki" <rafael@kernel.org>
CC:     <linux-pm@vger.kernel.org>, Len Brown <lenb@kernel.org>,
        "Srinivas Pandruvada" <srinivas.pandruvada@linux.intel.com>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        Robert Moore <robert.moore@intel.com>,
        <linux-acpi@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
        <devel@acpica.org>
Subject: Re: [PATCH 1/2] acpi: processor: allow fixing up the frequency for
 a performance state
References: <20221221155203.11347-1-ptyadav@amazon.de>
        <20221221155203.11347-2-ptyadav@amazon.de>
        <CAJZ5v0i-mrt57=2ROywn4Na_N3YVk+3D869QpHWqp9eo2NtGAw@mail.gmail.com>
Date:   Thu, 22 Dec 2022 23:18:04 +0100
In-Reply-To: <CAJZ5v0i-mrt57=2ROywn4Na_N3YVk+3D869QpHWqp9eo2NtGAw@mail.gmail.com>       (Rafael
 J. Wysocki's message of "Thu, 22 Dec 2022 17:23:41 +0100")
Message-ID: <mafs0edsrdqw3.fsf_-_@amazon.de>
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On Thu, Dec 22 2022, Rafael J. Wysocki wrote:
> On Wed, Dec 21, 2022 at 4:52 PM Pratyush Yadav <ptyadav@amazon.de> wrote:
>>
>> In some cases the ACPI table can have an incorrect frequency populated
>> for a performance state. For example, in Intel platforms, the Turbo
>> frequency is just listed as +1 MHz above the max non-turbo frequency.
>
> Which is a known convention based on compatibility with some older OSes.

Interesting. I did not know that.

>
>> The frequency can actually go much higher based on various factors like
>> temperature, voltage, etc.
>
> It can.
>
>> Allow drivers like intel_pstate to fix up performance state frequencies
>> with the actual maximum value.
>
> Why do you want to do that?

To be able to use my processors at the full frequency they are capable
of. See [0] for more details.

[0] https://lore.kernel.org/linux-pm/mafs0k02jd8oh.fsf_-_@dev-dsk-ptyadav-1c-37607b33.eu-west-1.amazon.com/

>
[...]

-- 
Regards,
Pratyush Yadav


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