Re: [edk2-devel] [edk2-platforms PATCH 2/7] Marvell: Armada7k8k/OcteonTx: Add missing _STA methods in ACPI tables

["Ard Biesheuvel" <ardb@kernel.org>]

On Tue, 10 Aug 2021 at 16:36, Samer El-Haj-Mahmoud
<samer.el-haj-mahmoud@arm.com> wrote:
>
> Apologies for the tardiness in replying to this. Please see my comments below.
>
> > -----Original Message-----
> > From: Marcin Wojtas <mw@semihalf.com>
> > Sent: Friday, July 30, 2021 5:57 AM
> > To: Ard Biesheuvel <ardb@kernel.org>
> > Cc: Samer El-Haj-Mahmoud <Samer.El-Haj-Mahmoud@arm.com>; edk2-
> > devel-groups-io <devel@edk2.groups.io>; Leif Lindholm
> > <leif@nuviainc.com>; Ard Biesheuvel <ardb+tianocore@kernel.org>;
> > Grzegorz Jaszczyk <jaz@semihalf.com>; Grzegorz Bernacki
> > <gjb@semihalf.com>; upstream@semihalf.com; Jon (jon@solid-run.com)
> > <jon@solid-run.com>
> > Subject: Re: [edk2-platforms PATCH 2/7] Marvell: Armada7k8k/OcteonTx:
> > Add missing _STA methods in ACPI tables
> >
> > Hi Ard,
> >
> > czw., 29 lip 2021 o 11:58 Ard Biesheuvel <ardb@kernel.org> napisał(a):
> > >
> > > On Thu, 29 Jul 2021 at 11:46, Marcin Wojtas <mw@semihalf.com> wrote:
> > > >
> > > > Hi Ard,
> > > >
> > > > pon., 19 lip 2021 o 17:06 Marcin Wojtas <mw@semihalf.com> napisał(a):
> > > > >
> > > > > Hi Ard,
> > > > >
> > > > > pon., 19 lip 2021 o 11:54 Ard Biesheuvel <ardb@kernel.org> napisał(a):
> > > > > >
> > > > > > On Mon, 19 Jul 2021 at 11:31, Marcin Wojtas <mw@semihalf.com>
> > wrote:
> > > > > > >
> > > > > > > BBR 1.0 spec says that _STA is required for each device in DSDT or
> > SSDT.
> > > > > > > Fix that for all platforms with the Marvell SoC's.
> > > > > > >
> > > > > >
> > > > > > Can we fix the BBR instead? If ACPI itself does not require _STA, BBR
> > > > > > should not require it either.
> > > > > >
> > > > > >
> > > > >
> > > > > I consulted with ARM on the matter. SBBR has requirements of things
> > > > > that are otherwise optional in UEFI/ACPI/SMBIOS. Also some OS's may
> > > > > require that and I can see those methods in most of the other ACPI
> > > > > source files in the edk2-platfoms tree. I think the BBR requirements
> > > > > discussions can follow, but it would be great if this change can be
> > > > > applied, so that no to block other development.
> > > > >
> > > >
> > > > Do you have any feedback to the patchset and the _STA methods
> > concerns?
> > > >
> > >
> > > Yes. I would like to understand why _STA methods are now mandated by
> > BBR.
> > >
> >
> > Understood. Providing an answer may not be immediate and may possibly
> > require further discussion on the SystemArchAC level.
> > How about we withdraw this single patch for now and process the
> > remaining ones? We would come back to the _STA subject, as soon as
> > there's more information available.
> >
> > Best regards,
> > Marcin
> >
>
> _STA has been required in SBBR since ver 1.0 (published 2016, with the 0.9 draft since 2014)
> https://developer.arm.com/documentation/den0044/b/?lang=en
>
> I do not have the history on why SBBR 1.0+ requires _STA, but it most likely has to do wit the Windows strong use case for it: https://docs.microsoft.com/en-us/windows-hardware/drivers/bringup/device-management-namespace-objects#device-status-changes . Windows is a key OS targeted by SBBR.
>

OK, I stand corrected again :-)

Marcin,

I won't object further to these additions -please respin the patch on
top of current edk2-platform and I will apply it right away.