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Date:   Thu, 12 May 2022 13:16:29 +0530
From:   Viresh Kumar <viresh.kumar@linaro.org>
To:     Pierre Gondois <pierre.gondois@arm.com>
Cc:     linux-kernel@vger.kernel.org, Ionela.Voinescu@arm.com,
        Dietmar.Eggemann@arm.com, "Rafael J. Wysocki" <rafael@kernel.org>,
        Len Brown <lenb@kernel.org>,
        Robert Moore <robert.moore@intel.com>,
        linux-acpi@vger.kernel.org, linux-pm@vger.kernel.org,
        devel@acpica.org
Subject: Re: [PATCH v1 4/5] cpufreq: CPPC: Enable fast_switch
Message-ID: <20220512074629.3cewdk4pu3oydlfg@vireshk-i7>
References: <20220511134559.1466925-1-pierre.gondois@arm.com>
 <20220511134559.1466925-4-pierre.gondois@arm.com>
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On 11-05-22, 15:45, Pierre Gondois wrote:
> From: Pierre Gondois <Pierre.Gondois@arm.com>
> 
> The communication mean of the _CPC desired performance can be
> PCC, System Memory, System IO, or Functional Fixed Hardware.
> 
> commit b7898fda5bc7 ("cpufreq: Support for fast frequency switching")
> fast_switching is 'for switching CPU frequencies from interrupt
> context'.
> Writes to SystemMemory and SystemIo are fast and suitable this.
> This is not the case for PCC and might not be the case for FFH.
> 
> Enable fast_switching for the cppc_cpufreq driver in above cases.
> 
> Add cppc_allow_fast_switch() to check the desired performance
> register address space and set fast_switching accordingly.
> 
> Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
> ---
>  drivers/acpi/cppc_acpi.c       | 17 +++++++++++++++++
>  drivers/cpufreq/cppc_cpufreq.c | 24 ++++++++++++++++++++++++
>  include/acpi/cppc_acpi.h       |  5 +++++
>  3 files changed, 46 insertions(+)

Acked-by: Viresh Kumar <viresh.kumar@linaro.org>

-- 
viresh