From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757151Ab0E0OTz (ORCPT ); Thu, 27 May 2010 10:19:55 -0400 Received: from casper.infradead.org ([85.118.1.10]:46979 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755339Ab0E0OTw (ORCPT ); Thu, 27 May 2010 10:19:52 -0400 Date: Thu, 27 May 2010 07:22:07 -0700 From: Arjan van de Ven To: Kevin Hilman 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 Message-ID: <20100527072207.2e783b1e@infradead.org> In-Reply-To: <87ljb5l9d5.fsf@deeprootsystems.com> References: <1274928151-30919-1-git-send-email-lenb@kernel.org> <198450ec1600d9a7f55270dd4d44d6b55bc5b184.1274926772.git.len.brown@intel.com> <87ljb5l9d5.fsf@deeprootsystems.com> Organization: Intel X-Mailer: Claws Mail 3.7.5 (GTK+ 2.16.6; i586-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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; it's much more convenient for cpuidle developers if they're all in one place. Think of it this way: you're not putting the NIC driver for your SOC in a architecture directory either... -- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org