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