-----Original Message----- From: Catalin Marinas [mailto:catalin.marinas@arm.com] Sent: 06 January 2015 14:17 To: Arnd Bergmann Cc: linux-arm-kernel@lists.infradead.org; hanjun.guo@linaro.org; Mark Rutland; linaro-acpi@lists.linaro.org; Will Deacon; Lv Zheng; Rob Herring; Lorenzo Pieralisi; Al Stone; Daniel Lezcano; Robert Moore; linux-acpi@vger.kernel.org; jcm@redhat.com; grant.likely@linaro.org; Charles Garcia-Tobin; Robert Richter; Jason Cooper; Marc Zyngier; Liviu Dudau; Mark Brown; Bjorn Helgaas; graeme.gregory@linaro.org; Kangkang.Shen@huawei.com; Randy Dunlap; Rafael J. Wysocki; linux- kernel@vger.kernel.org; Sudeep Holla; Olof Johansson Subject: Re: [PATCH v5 18/18] Documentation: ACPI for ARM64
On Tue, Jan 06, 2015 at 02:05:12PM +0000, Arnd Bergmann wrote:
On Tuesday 06 January 2015 11:29:29 Catalin Marinas wrote:
We will work on this both on ASWG and linux ACPI driver side,
as Dong
and Charles pointed out, _OSI things can be solved in ACPI
spec, when
that is done, we can modify the kernel driver to fix the
problems above.
Which driver?
the ACPICA core driver as you suggested, sorry for the confusion.
What about ACPI_OS_NAME? Would you suggest it is fine to report "Microsoft Windows NT" on an ARM system? That _OS_ not _OSI.
No, not at all. I prefer "Linux" In include/acpi/acconfig.h, when ACPI_OS_NAME defined, it says: "OS name, used for the _OS object. The _OS object is essentially obsolete,..." for some legacy reasons, we needed "Microsoft Windows NT", but
ACPI
for ARM64 on linux is totally new, I think we can change it to "Linux" when CONFIG_ARM64 as you suggested.
We could ignore this change for now if we don't expect the _OS
object to
be used at all. But do we have any other way to check the AML code
for
this? Would FWTS catch such obsolete cases?
How about just leaving it out? It's clearly not used for anything good, so I don't see the point in passing either Linux or "Microsoft Windows NT" here.
Do you mean defining it to NULL (so it ends up as NULL in acpi_gbl_pre_defined_names) or removing "_OS_" entirely from that array? I really can't tell what the implications are.
To me, given that we don't want to use it in ARM64, it would make sense to have some method to configurably: 0. Leave as is 1. Warn for usage 2. Panic With a configurability method that allows FWTS to make use of it, and therefore catch usages of the method.
Cheers
Charles
-- Catalin