Re: [PATCH] ACPI/PPTT: use ACPI ID whenever ACPI_PPTT_ACPI_PROCESSOR_ID_VALID is set

From: Rafael J. Wysocki
Date: Mon Jul 02 2018 - 05:06:35 EST


On Fri, Jun 29, 2018 at 6:17 PM, Sudeep Holla <sudeep.holla@xxxxxxx> wrote:
> Currently we use the ACPI processor ID only for the leaf/processor nodes
> as the specification states it must match the value of ACPI processor ID
> field in the processorâs entry in the MADT.
>
> However, if a PPTT structure represents processors group, it match a
> processor container UID in the namespace and ACPI_PPTT_ACPI_PROCESSOR_ID_VALID
> flag describe whether the ACPI processor ID is valid.
>
> Lets use UID whenever ACPI_PPTT_ACPI_PROCESSOR_ID_VALID is set to be
> consistent instead of using table offset as it's currently done for non
> leaf nodes.
>
> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx>
> Signed-off-by: Sudeep Holla <sudeep.holla@xxxxxxx>
> ---
> drivers/acpi/pptt.c | 10 ++++++++--
> 1 file changed, 8 insertions(+), 2 deletions(-)
>
> Hi,
>
> There's ongoing discussion on assigning ID based in OS using simple
> counters. It can never be consistent with firmware's view. So if the
> firmware provides valid UID for non-processors node, we must use it.

OK

Do you regard this as a fix for the recently merged PPTT material? If
so, I should apply it as a fix for 4.18.

Thanks,
Rafael