| Message ID | 20231030071832.2217118-2-Jun.Ma2@amd.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Enable Wifi RFI interference mitigation feature support | expand |
On Mon, 30 Oct 2023, Ma Jun wrote: > Add documentation about AMD's Wifi band RFI mitigation (WBRF) mechanism > explaining the theory and how it is used. > > Signed-off-by: Ma Jun <Jun.Ma2@amd.com> > --- > Documentation/driver-api/wbrf.rst | 76 +++++++++++++++++++++++++++++++ > 1 file changed, 76 insertions(+) > create mode 100644 Documentation/driver-api/wbrf.rst > > +Driver programming interface > +============================ > +.. kernel-doc:: drivers/platform/x86/amd/wbrf.c > + > +Sample Usage > +============= A lot better but you missed adding newlines here for this and previous section title. > +The expected flow for the producers: > +1). During probe, call `acpi_amd_wbrf_supported_producer` to check if WBRF > + can be enabled for the device. > +2). On using some frequency band, call `acpi_amd_wbrf_add_remove` with 'add' > + param to get other consumers properly notified. > +3). Or on stopping using some frequency band, call > + `acpi_amd_wbrf_add_remove` with 'remove' param to get other consumers notified. > + > +The expected flow for the consumers: > +1). During probe, call `acpi_amd_wbrf_supported_consumer` to check if WBRF > + can be enabled for the device. > +2). Call `amd_wbrf_register_notifier` to register for notification > + of frequency band change(add or remove) from other producers. > +3). Call the `amd_wbrf_retrieve_freq_band` intentionally to retrieve > + current active frequency bands considering some producers may broadcast > + such information before the consumer is up. > +4). On receiving a notification for frequency band change, run > + `amd_wbrf_retrieve_freq_band` again to retrieve the latest > + active frequency bands. > +5). During driver cleanup, call `amd_wbrf_unregister_notifier` to > + unregister the notifier. The correct kerneldoc format should be without the closing parenthesis: 1. Text here that spills to second line. 2. Second entry.
Hi llpo, Thanks for review, I'll fix the format issue in the next version. Regards, Ma Jun On 11/20/2023 7:59 PM, Ilpo Järvinen wrote: > On Mon, 30 Oct 2023, Ma Jun wrote: > >> Add documentation about AMD's Wifi band RFI mitigation (WBRF) mechanism >> explaining the theory and how it is used. >> >> Signed-off-by: Ma Jun <Jun.Ma2@amd.com> >> --- >> Documentation/driver-api/wbrf.rst | 76 +++++++++++++++++++++++++++++++ >> 1 file changed, 76 insertions(+) >> create mode 100644 Documentation/driver-api/wbrf.rst >> >> +Driver programming interface >> +============================ >> +.. kernel-doc:: drivers/platform/x86/amd/wbrf.c >> + >> +Sample Usage >> +============= > > A lot better but you missed adding newlines here for this and previous > section title. > >> +The expected flow for the producers: >> +1). During probe, call `acpi_amd_wbrf_supported_producer` to check if WBRF >> + can be enabled for the device. >> +2). On using some frequency band, call `acpi_amd_wbrf_add_remove` with 'add' >> + param to get other consumers properly notified. >> +3). Or on stopping using some frequency band, call >> + `acpi_amd_wbrf_add_remove` with 'remove' param to get other consumers notified. >> + >> +The expected flow for the consumers: >> +1). During probe, call `acpi_amd_wbrf_supported_consumer` to check if WBRF >> + can be enabled for the device. >> +2). Call `amd_wbrf_register_notifier` to register for notification >> + of frequency band change(add or remove) from other producers. >> +3). Call the `amd_wbrf_retrieve_freq_band` intentionally to retrieve >> + current active frequency bands considering some producers may broadcast >> + such information before the consumer is up. >> +4). On receiving a notification for frequency band change, run >> + `amd_wbrf_retrieve_freq_band` again to retrieve the latest >> + active frequency bands. >> +5). During driver cleanup, call `amd_wbrf_unregister_notifier` to >> + unregister the notifier. > > The correct kerneldoc format should be without the closing parenthesis: > > 1. Text here that > spills to second line. > 2. Second entry. >
diff --git a/Documentation/driver-api/wbrf.rst b/Documentation/driver-api/wbrf.rst new file mode 100644 index 000000000000..52527e76cad4 --- /dev/null +++ b/Documentation/driver-api/wbrf.rst @@ -0,0 +1,76 @@ +.. SPDX-License-Identifier: GPL-2.0-or-later + +================================= +WBRF - Wifi Band RFI Mitigations +================================= + +Due to electrical and mechanical constraints in certain platform designs +there may be likely interference of relatively high-powered harmonics of +the GPU memory clocks with local radio module frequency bands used by +certain Wifi bands. + +To mitigate possible RFI interference producers can advertise the +frequencies in use and consumers can use this information to avoid using +these frequencies for sensitive features. + +When a platform is known to have this issue with any contained devices, +the platform designer will advertise the availability of this feature via +ACPI devices with a device specific method (_DSM). +* Producers with this _DSM will be able to advertise the frequencies in use. +* Consumers with this _DSM will be able to register for notifications of +frequencies in use. + +Some general terms +================== + +Producer: such component who can produce high-powered radio frequency +Consumer: such component who can adjust its in-use frequency in + response to the radio frequencies of other components to + mitigate the possible RFI. + +To make the mechanism function, those producers should notify active use +of their particular frequencies so that other consumers can make relative +internal adjustments as necessary to avoid this resonance. + +ACPI interface +============== + +Although initially used by for wifi + dGPU use cases, the ACPI interface +can be scaled to any type of device that a platform designer discovers +can cause interference. + +The GUID used for the _DSM is 7B7656CF-DC3D-4C1C-83E9-66E721DE3070. + +3 functions are available in this _DSM: + +* 0: discover # of functions available +* 1: record RF bands in use +* 2: retrieve RF bands in use + +Driver programming interface +============================ +.. kernel-doc:: drivers/platform/x86/amd/wbrf.c + +Sample Usage +============= +The expected flow for the producers: +1). During probe, call `acpi_amd_wbrf_supported_producer` to check if WBRF + can be enabled for the device. +2). On using some frequency band, call `acpi_amd_wbrf_add_remove` with 'add' + param to get other consumers properly notified. +3). Or on stopping using some frequency band, call + `acpi_amd_wbrf_add_remove` with 'remove' param to get other consumers notified. + +The expected flow for the consumers: +1). During probe, call `acpi_amd_wbrf_supported_consumer` to check if WBRF + can be enabled for the device. +2). Call `amd_wbrf_register_notifier` to register for notification + of frequency band change(add or remove) from other producers. +3). Call the `amd_wbrf_retrieve_freq_band` intentionally to retrieve + current active frequency bands considering some producers may broadcast + such information before the consumer is up. +4). On receiving a notification for frequency band change, run + `amd_wbrf_retrieve_freq_band` again to retrieve the latest + active frequency bands. +5). During driver cleanup, call `amd_wbrf_unregister_notifier` to + unregister the notifier.
Add documentation about AMD's Wifi band RFI mitigation (WBRF) mechanism explaining the theory and how it is used. Signed-off-by: Ma Jun <Jun.Ma2@amd.com> --- Documentation/driver-api/wbrf.rst | 76 +++++++++++++++++++++++++++++++ 1 file changed, 76 insertions(+) create mode 100644 Documentation/driver-api/wbrf.rst