On 6 January 2015 at 13:50, Hanjun Guo <hanjun.guo@xxxxxxxxxx> wrote: > On 2015年01月06日 19:29, Catalin Marinas wrote: >> >> On Tue, Jan 06, 2015 at 11:11:07AM +0000, Hanjun Guo wrote: >>> >>> On 2015年01月05日 19:05, Catalin Marinas wrote: >>>> >>>> On Sun, Jan 04, 2015 at 09:39:24AM +0000, Hanjun Guo wrote: >>>>> >>>>> On 2014年12月25日 01:18, Catalin Marinas wrote: >>>>> [...] >>>>>> >>>>>> >>>>>> In addition to the above and _DSD requirements/banning, I would also >>>>>> add >>>>>> some clear statements around: >>>>>> >>>>>> _OSC: only global/published capabilities are allowed. For >>>>>> device-specific _OSC we need a process or maybe we can ban them >>>>>> entirely >>>>>> and rely on _DSD once we clarify the process. >>>>>> >>>>>> _OSI: firmware must not check for certain _OSI strings. Here I'm not >>>>>> sure what we would have to do for ARM Linux. Reporting "Windows" does >>>>>> not make any sense but not reporting anything can, as Matthew Garrett >>>>>> pointed out, can be interpreted by firmware as "Linux". In addition to >>>>>> any statements in this document, I suggest you patch >>>>>> drivers/acpi/acpica/utosi.c accordingly, maybe report "Linux" for ARM >>>>>> and print a kernel warning so that we notice earlier. >>>>>> >>>>>> ACPI_OS_NAME: this is globally defined as "Microsoft Windows NT". It >>>>>> doesn't make much sense in the ARM context. Could we change it to >>>>>> "Linux" when CONFIG_ARM64? >>> >>> >>> I think we can introduce a Kconfig such as CONFIG_ACPI_OS_NAME_LINUX, >>> selected by ARM64 and change ACPI_OS_NAME to "Linux" when >>> CONFIG_ACPI_OS_NAME_LINUX defined. (we can not add CONFIG_ARM64 in >>> ACPICA code directly since it will be used by windows too) >>> >>> some code like below: >> >> >> This looks fine for me (with some minor comments below) but I'm not an >> ACPI expert to say there wouldn't be any issues. >> >>> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig >>> index b1f9a20..de567a3 100644 >>> --- a/arch/arm64/Kconfig >>> +++ b/arch/arm64/Kconfig >>> @@ -1,5 +1,6 @@ >>> config ARM64 >>> def_bool y >>> + select ACPI_OS_NAME_LINUX if ACPI >>> select ARCH_BINFMT_ELF_RANDOMIZE_PIE >>> select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE >>> select ARCH_HAS_GCOV_PROFILE_ALL >>> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig >>> index 8951cef..11a10ac 100644 >>> --- a/drivers/acpi/Kconfig >>> +++ b/drivers/acpi/Kconfig >>> @@ -369,6 +369,10 @@ config ACPI_REDUCED_HARDWARE_ONLY >>> >>> If you are unsure what to do, do not enable this option. >>> >>> +config ACPI_OS_NAME_LINUX >>> + bool "Using Linux for _OS method" if EXPERT >>> + def_bool n >> >> >> No need for a default n, it is off by default. Alternatively you could >> say: >> >> default y if ARM64 > > > ok. > >> >>> + >>> source "drivers/acpi/apei/Kconfig" >>> >>> config ACPI_EXTLOG >>> diff --git a/include/acpi/acconfig.h b/include/acpi/acconfig.h >>> index 5a0a3e5..db5e13e 100644 >>> --- a/include/acpi/acconfig.h >>> +++ b/include/acpi/acconfig.h >>> @@ -69,7 +69,11 @@ >>> * code that will not execute the _OSI method unless _OS matches the >>> string >>> * below. Therefore, change this string at your own risk. >>> */ >>> +#ifndef ACPI_OS_NAME_USING_LINUX >>> #define ACPI_OS_NAME "Microsoft Windows NT" >>> +#else >>> +#define ACPI_OS_NAME "Linux" >>> +#endif >> >> >> Can you not use CONFIG_ACPI_OS_NAME_LINUX directly here without >> introducing another macro? > > > acconfig.h is part of ACPICA core and will be shared by windows and > other OS, so use CONFIG from Linux in this file is not allowed I think. > We could just propse #ifndef ACPI_OS_NAME #define ACPI_OS_NAME "Microsoft Windows NT" #endif to acpica maintainers. This will not alter Windows or other software usage but we can then override it in Linux when/if we want to. Graeme -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
