Re: [PATCH V4 1/8] drivers/acpi: Add support for Wifi band RF mitigations

Andrew Lunn
2023-06-21T15:39:27Z

On Wed, Jun 21, 2023 at 01:45:56PM +0800, Evan Quan 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.

Do only ACPI based systems have:

interference of relatively high-powered harmonics of the (G-)DDR
memory clocks with local radio module frequency bands used by
Wifi 6/6e/7."

Could Device Tree based systems not experience this problem?

> +/**
> + * APIs needed by drivers/subsystems for contributing frequencies:
> + * During probe, check `wbrf_supported_producer` to see if WBRF is supported.
> + * If adding frequencies, then call `wbrf_add_exclusion` with the
> + * start and end points specified for the frequency ranges added.
> + * If removing frequencies, then call `wbrf_remove_exclusion` with
> + * start and end points specified for the frequency ranges added.
> + */
> +bool wbrf_supported_producer(struct acpi_device *adev);
> +int wbrf_add_exclusion(struct acpi_device *adev,
> + struct wbrf_ranges_in *in);
> +int wbrf_remove_exclusion(struct acpi_device *adev,
> + struct wbrf_ranges_in *in);

Could struct device be used here, to make the API agnostic to where
the information is coming from? That would then allow somebody in the
future to implement a device tree based information provider.

Andrew