From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from e23smtp05.au.ibm.com (e23smtp05.au.ibm.com [202.81.31.147]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "e23smtp05.au.ibm.com", Issuer "GeoTrust SSL CA" (not verified)) by ozlabs.org (Postfix) with ESMTPS id A50582C00C7 for ; Wed, 31 Jul 2013 14:02:24 +1000 (EST) Received: from /spool/local by e23smtp05.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Wed, 31 Jul 2013 13:55:14 +1000 Received: from d23relay04.au.ibm.com (d23relay04.au.ibm.com [9.190.234.120]) by d23dlp02.au.ibm.com (Postfix) with ESMTP id 2CC5D2BB0053 for ; Wed, 31 Jul 2013 14:01:58 +1000 (EST) Received: from d23av01.au.ibm.com (d23av01.au.ibm.com [9.190.234.96]) by d23relay04.au.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id r6V3kQvU33357984 for ; Wed, 31 Jul 2013 13:46:26 +1000 Received: from d23av01.au.ibm.com (localhost [127.0.0.1]) by d23av01.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id r6V41u2G025838 for ; Wed, 31 Jul 2013 14:01:57 +1000 Message-ID: <51F88BA7.7090404@linux.vnet.ibm.com> Date: Wed, 31 Jul 2013 09:29:35 +0530 From: Preeti U Murthy MIME-Version: 1.0 To: Wang Dongsheng-B40534 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 Cc: Deepthi Dharwar , "linux-pm@vger.kernel.org" , "daniel.lezcano@linaro.org" , "rjw@sisk.pl" , "linux-kernel@vger.kernel.org" , "srivatsa.bhat@linux.vnet.ibm.com" , "linuxppc-dev@lists.ozlabs.org" List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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