From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754784AbbIXNFU (ORCPT ); Thu, 24 Sep 2015 09:05:20 -0400 Received: from foss.arm.com ([217.140.101.70]:38379 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753294AbbIXNFR (ORCPT ); Thu, 24 Sep 2015 09:05:17 -0400 Subject: Re: [PATCH v2 4/5] ACPI / processor_idle : introduce ARCH_SUPPORTS_ACPI_PROCESSOR_CSTATE To: Ashwin Chaugule 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> Cc: Sudeep Holla , linux acpi , "Rafael J. Wysocki" , lkml , "linux-ia64@vger.kernel.org" , "x86@kernel.org" , Al Stone , Lorenzo Pieralisi , Mahesh Sivasubramanian From: Sudeep Holla Message-ID: <5603F509.1090307@arm.com> Date: Thu, 24 Sep 2015 14:05:13 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.2.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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