From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757611Ab0E0Ogv (ORCPT ); Thu, 27 May 2010 10:36:51 -0400 Received: from mail-pw0-f46.google.com ([209.85.160.46]:56745 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755488Ab0E0Ogr (ORCPT ); Thu, 27 May 2010 10:36:47 -0400 To: Arjan van de Ven Cc: Len Brown , 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> <87ljb5l9d5.fsf@deeprootsystems.com> <20100527072207.2e783b1e@infradead.org> From: Kevin Hilman Organization: Deep Root Systems, LLC Date: Thu, 27 May 2010 07:36:40 -0700 In-Reply-To: <20100527072207.2e783b1e@infradead.org> (Arjan van de Ven's message of "Thu\, 27 May 2010 07\:22\:07 -0700") Message-ID: <87ocg1jts7.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 Arjan van de Ven writes: > On Thu, 27 May 2010 07:14:46 -0700 > Kevin Hilman wrote: > >> 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. >> > > it's really inconvenient to have such drivers hidden in the > architecture code; I'm not sure how puting architecture-specific code into an architecture-specific directory is hiding it, but maybe I'm missing something. > it's much more convenient for cpuidle developers if they're all in > one place. So should we move all the embedded SoC specific CPUidle drivers into drivers/idle too? To me that would be much less convenient as I expect to maintain my platform-specific CPUidle driver along with the rest of my platform-specific code. Kevin