From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755050Ab0E0OOw (ORCPT ); Thu, 27 May 2010 10:14:52 -0400 Received: from mail-pv0-f174.google.com ([74.125.83.174]:44937 "EHLO mail-pv0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753118Ab0E0OOv (ORCPT ); Thu, 27 May 2010 10:14:51 -0400 To: Len Brown Cc: x86@kernel.org, linux-pm@lists.linux-foundation.org, linux-kernel@vger.kernel.org, Len Brown Subject: Re: [PATCH 8/8] intel_idle: create a native cpuidle driver for select intel processors References: <1274928151-30919-1-git-send-email-lenb@kernel.org> <198450ec1600d9a7f55270dd4d44d6b55bc5b184.1274926772.git.len.brown@intel.com> From: Kevin Hilman Organization: Deep Root Systems, LLC Date: Thu, 27 May 2010 07:14:46 -0700 In-Reply-To: <198450ec1600d9a7f55270dd4d44d6b55bc5b184.1274926772.git.len.brown@intel.com> (Len Brown's message of "Wed\, 26 May 2010 22\:42\:31 -0400") Message-ID: <87ljb5l9d5.fsf@deeprootsystems.com> User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Len Brown writes: > From: Len Brown > > This EXPERIMENTAL driver supersedes acpi_idle > on modern Intel processors. (Nehalem and Atom Processors). > > For CONFIG_INTEL_IDLE=y, intel_idle probes before acpi_idle, > no matter if CONFIG_ACPI_PROCESSOR=y or =m. > > Boot with "intel_idle.max_cstate=0" to disable the driver > and to fall back on ACPI. > > CONFIG_INTEL_IDLE=m is not recommended unless the system > has a method to guarantee intel_idle loads before ACPI's > processor_idle. > > This driver does not yet know about cpu online/offline > and thus will not yet play well with cpu-hotplug. > > Signed-off-by: Len Brown > --- > MAINTAINERS | 7 + > drivers/Makefile | 2 +- > drivers/acpi/processor_driver.c | 6 +- > drivers/idle/Kconfig | 11 + > drivers/idle/Makefile | 1 + > drivers/idle/intel_idle.c | 446 +++++++++++++++++++++++++++++++++++++++ Any reason this arch-specific driver needs to be in drivers/idle instead of under a platform specific dir like arch/x86? On embedded SoCs that have never had ACPI, we have our platform-specific CPUidle drivers in with the rest of our platform specific code. Kevin