From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sudeep Holla Date: Thu, 24 Sep 2015 13:05:13 +0000 Subject: Re: [PATCH v2 4/5] ACPI / processor_idle : introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE Message-Id: <5603F509.1090307@arm.com> List-Id: References: <1438710406-3822-1-git-send-email-sudeep.holla@arm.com> <1442411963-14398-1-git-send-email-sudeep.holla@arm.com> <1442411963-14398-5-git-send-email-sudeep.holla@arm.com> In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Ashwin Chaugule Cc: Sudeep Holla , linux acpi , "Rafael J. Wysocki" , lkml , "linux-ia64@vger.kernel.org" , "x86@kernel.org" , Al Stone , Lorenzo Pieralisi , Mahesh Sivasubramanian On 24/09/15 11:31, Ashwin Chaugule wrote: > Hi Sudeep, > > On 16 September 2015 at 09:59, Sudeep Holla wrote: >> ACPI 6.0 adds a new method to specify the CPU idle states(C-states) >> called Low Power Idle(LPI) states. Since new architectures like ARM64 >> use only LPIs, introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE to >> encapsulate all the code supporting the old style C-states(_CST) >> >> This patch will help to extend the processor_idle module to support >> LPI. >> >> Cc: "Rafael J. Wysocki" >> Signed-off-by: Sudeep Holla [...] >> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig >> index 7aef2d52daa0..173075c48df8 100644 >> --- a/arch/x86/Kconfig >> +++ b/arch/x86/Kconfig >> @@ -34,6 +34,7 @@ config X86 >> select ARCH_MIGHT_HAVE_ACPI_PDC if ACPI >> select ARCH_MIGHT_HAVE_PC_PARPORT >> select ARCH_MIGHT_HAVE_PC_SERIO >> + select ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE if ACPI >> select ARCH_SUPPORTS_ATOMIC_RMW >> select ARCH_SUPPORTS_DEFERRED_STRUCT_PAGE_INIT >> select ARCH_SUPPORTS_INT128 if X86_64 >> diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig >> index 5d1015c26ff4..1eb0b8a84a65 100644 >> --- a/drivers/acpi/Kconfig >> +++ b/drivers/acpi/Kconfig >> @@ -48,6 +48,9 @@ config ACPI_LEGACY_TABLES_LOOKUP >> config ARCH_MIGHT_HAVE_ACPI_PDC >> bool >> >> +config ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE >> + bool >> + >> config ACPI_GENERIC_GSI >> bool >> > > Can't this be auto selected under ACPI_PROCESSOR_IDLE if X86 || IA64 > instead? It can be done. The idea was to have ACPI_PROCESSOR_IDLE selected on both x86 and ARM64. processor_idle driver will support both _CST and _LPI 1. to avoid some code duplication 2. for easy enabling of _LPI on x86 if needed in future Regards, Sudeep