Re: [PATCH 3/3] Documentation/arm64: Update ACPI tables from BBR

[Robin Murphy <robin.murphy@arm.com>]

On 2023-05-18 13:07, Hanjun Guo wrote:
> Hi Jose,
> 
> On 2023/5/18 18:52, Jose Marinho wrote:
>> The BBR specification requires (or conditionally requires) a set of ACPI
>> tables for a proper working system.
>> This commit updates:
>> - the list of ACPI tables to reflect the contents of
>> BBR version 2.0 (see https://developer.arm.com/documentation/den0044/g).
>> - the list of ACPI tables in acpi_object_usage. This last update ensures
>> that both files remain coherent.
> 
> Thanks for the update, some comments inline.
> 
>>
>> Signed-off-by: Jose Marinho <jose.marinho@arm.com>
>> Reviewed-by: Samer El-Haj-Mahmoud <Samer.El-Haj-Mahmoud@arm.com>
>> ---
>>   Documentation/arm64/acpi_object_usage.rst | 81 +++++++++++++++++++++--
>>   Documentation/arm64/arm-acpi.rst          | 71 +++++++++++++++++---
>>   2 files changed, 139 insertions(+), 13 deletions(-)
>>
>> diff --git a/Documentation/arm64/acpi_object_usage.rst 
>> b/Documentation/arm64/acpi_object_usage.rst
>> index 484ef9676653..1da22200fdf8 100644
>> --- a/Documentation/arm64/acpi_object_usage.rst
>> +++ b/Documentation/arm64/acpi_object_usage.rst
>> @@ -17,16 +17,37 @@ For ACPI on arm64, tables also fall into the 
>> following categories:
>>          -  Recommended: BERT, EINJ, ERST, HEST, PCCT, SSDT
>> -       -  Optional: BGRT, CPEP, CSRT, DBG2, DRTM, ECDT, FACS, FPDT, 
>> IBFT,
>> -          IORT, MCHI, MPST, MSCT, NFIT, PMTT, RASF, SBST, SLIT, SPMI, 
>> SRAT,
>> -          STAO, TCPA, TPM2, UEFI, XENV
>> +       -  Optional: AGDI, BGRT, CEDT, CPEP, CSRT, DBG2, DRTM, ECDT, 
>> FACS, FPDT,
>> +          HMAT, IBFT, IORT, MCHI, MPAM, MPST, MSCT, NFIT, PMTT, PPTT, 
>> RASF, SBST,
>> +          SDEI, SLIT, SPMI, SRAT, STAO, TCPA, TPM2, UEFI, XENV
>> -       -  Not supported: BOOT, DBGP, DMAR, ETDT, HPET, IVRS, LPIT, 
>> MSDM, OEMx,
>> -          PSDT, RSDT, SLIC, WAET, WDAT, WDRT, WPBT
>> +       -  Not supported: AEST, APMT, BOOT, DBGP, DMAR, ETDT, HPET, 
>> IVRS, LPIT,
> 
> AEST is ARM Error Source Table, and it can be used for ARM platforms, so
> I thinsk AEST is not belong to "Not supportted", "Optional" instead.

Can you point to the code in Linux which does anything with AEST, 
optionally or otherwise? ;)
> and APMT is the same.
> 
>> +          MSDM, OEMx, PDTT, PSDT, RAS2, RSDT, SLIC, WAET, WDAT, WDRT, 
>> WPBT
> 
> PDTT and RAS2 are now used for ARM too, please move it to Optional :)

Ditto; as stated in arm-acpi.rst this is Linux documentation covering 
the interaction between Linux and ACPI. It is not some kind of generic 
ACPI-on-Arm guidance whitepaper. If and when Linux actually supports 
these tables in the sense of meaningfully consuming them, that is when 
we can document such support.

Thanks,
Robin.