Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751157Ab3GaECY (ORCPT ); Wed, 31 Jul 2013 00:02:24 -0400 Received: from e23smtp02.au.ibm.com ([202.81.31.144]:48220 "EHLO e23smtp02.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750808Ab3GaECW (ORCPT ); Wed, 31 Jul 2013 00:02:22 -0400 Message-ID: <51F88BA7.7090404@linux.vnet.ibm.com> Date: Wed, 31 Jul 2013 09:29:35 +0530 From: Preeti U Murthy User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:14.0) Gecko/20120717 Thunderbird/14.0 MIME-Version: 1.0 To: Wang Dongsheng-B40534 CC: Deepthi Dharwar , "benh@kernel.crashing.org" , "daniel.lezcano@linaro.org" , "linux-kernel@vger.kernel.org" , "michael@ellerman.id.au" , "srivatsa.bhat@linux.vnet.ibm.com" , "svaidy@linux.vnet.ibm.com" , "linuxppc-dev@lists.ozlabs.org" , "rjw@sisk.pl" , "linux-pm@vger.kernel.org" Subject: Re: [PATCH V2 4/6] cpuidle/pseries: Move the pseries_idle backend driver to sysdev. References: <20130731025840.19448.24468.stgit@deepthi> <20130731025924.19448.46538.stgit@deepthi> In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-TM-AS-MML: No X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13073103-5490-0000-0000-000003E99021 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2058 Lines: 51 Hi Dongsheng, On 07/31/2013 08:52 AM, Wang Dongsheng-B40534 wrote: > > >> -----Original Message----- >> From: Deepthi Dharwar [mailto:deepthi@linux.vnet.ibm.com] >> Sent: Wednesday, July 31, 2013 10:59 AM >> To: benh@kernel.crashing.org; daniel.lezcano@linaro.org; linux- >> kernel@vger.kernel.org; michael@ellerman.id.au; >> srivatsa.bhat@linux.vnet.ibm.com; preeti@linux.vnet.ibm.com; >> svaidy@linux.vnet.ibm.com; linuxppc-dev@lists.ozlabs.org >> Cc: rjw@sisk.pl; Wang Dongsheng-B40534; linux-pm@vger.kernel.org >> Subject: [PATCH V2 4/6] cpuidle/pseries: Move the pseries_idle backend >> driver to sysdev. >> >> Move pseries_idle backend driver code to arch/powerpc/sysdev >> so that the code can be used for a common driver for powernv >> and pseries. This removes a lot of code duplicacy. >> > Why not drivers/cpuidle/? > > I think it should be move to drivers/cpuidle. Please take a look at what the cpuidle under drivers has to provide. cpuidle has two parts to it. The front end and the back end. The front end constitutes the cpuidle governors, registering of arch specific cpuidle drivers, disabling and enabling of cpuidle feature. It is this front end code which is present under drivers/cpuidle. The arch specific cpuidle drivers which decide what needs to be done to enter a specific idle state chosen by the cpuidle governor is what constitutes the back end of cpuidle. This will not be in drivers/cpuidle but in an arch/ specific code. The cpuidle under drivers/cpuidle drives the idle power management, but the low level handling of the entry into idle states should be taken care of by the architecture. Your recent patch : cpuidle: add freescale e500 family porcessors idle support IMO should hook onto the backend cpuidle driver that this patchset provides. Regards Preeti U Murthy -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/