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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Fri, 23 Jun 2023 16:52:55 +0200
Message-ID: <CAJZ5v0iqy0yMJP5H7ub67R8R6i42=TcS_6+VF-+fWrM-9tYFQA@mail.gmail.com>
Subject: Re: [PATCH V4 1/8] drivers/acpi: Add support for Wifi band RF mitigations
To:     Evan Quan <evan.quan@amd.com>
Cc:     rafael@kernel.org, lenb@kernel.org, alexander.deucher@amd.com,
        christian.koenig@amd.com, Xinhui.Pan@amd.com, airlied@gmail.com,
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        edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
        mario.limonciello@amd.com, mdaenzer@redhat.com,
        maarten.lankhorst@linux.intel.com, tzimmermann@suse.de,
        hdegoede@redhat.com, jingyuwang_vip@163.com, lijo.lazar@amd.com,
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On Wed, Jun 21, 2023 at 7:47 AM Evan Quan <evan.quan@amd.com> wrote:
>
> From: Mario Limonciello <mario.limonciello@amd.com>
>
> Due to electrical and mechanical constraints in certain platform designs
> there may be likely interference of relatively high-powered harmonics of
> the (G-)DDR memory clocks with local radio module frequency bands used
> by Wifi 6/6e/7.
>
> To mitigate this, AMD has introduced an ACPI based mechanism that
> devices can use to notify active use of particular frequencies so
> that devices can make relative internal adjustments as necessary
> to avoid this resonance.
>
> In order for a device to support this, the expected flow for device
> driver or subsystems:
>
> Drivers/subsystems contributing frequencies:
>
> 1) During probe, check `wbrf_supported_producer` to see if WBRF supported

The prefix should be acpi_wbrf_ or acpi_amd_wbrf_ even, so it is clear
that this uses ACPI and is AMD-specific.

Whether or not there needs to be an intermediate library wrapped
around this is a different matter.