From patchwork Tue Apr 23 12:51:41 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Daniel Lezcano X-Patchwork-Id: 2477471 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork1.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork1.kernel.org (Postfix) with ESMTP id 49A023FCA5 for ; Tue, 23 Apr 2013 12:51:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755872Ab3DWMvr (ORCPT ); Tue, 23 Apr 2013 08:51:47 -0400 Received: from mail-ee0-f54.google.com ([74.125.83.54]:33997 "EHLO mail-ee0-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755463Ab3DWMvr (ORCPT ); Tue, 23 Apr 2013 08:51:47 -0400 Received: by mail-ee0-f54.google.com with SMTP id e51so249528eek.13 for ; Tue, 23 Apr 2013 05:51:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=x-received:message-id:date:from:user-agent:mime-version:to:cc :subject:references:in-reply-to:content-type :content-transfer-encoding:x-gm-message-state; bh=jQVHYdcfvFnCqECv8biSlFGGCesr4EU/ovxXi4QOxdw=; b=M5odyuifY0dfe6fYM93WsdGHpRQ85QjZBn4I3O63N1vPtPtIS+DvGYnXZdZmXOVS0M oSLqdwzR69W8przPFimEGI9g/0KYE1YNKNkTjQ1MBxZGUdBnQaEDzfBCp9dTdmy3X2l3 q1OLUKMBSZ7TTsdt8Jzm5BMCKocTTpIeylcGWWq7yJKAPbxP/jPUUhaCUv74sA8SKKYF Sk3FXRqxWnlEFm531RtUx1iEGOppvqh7WV1z2iEzR3nzdvsUY58YzZLqhUfoQfxbknKJ GRmMTONdEMb9OYR05Jacl2znslWD2IdLZH0s8kmPp7TChZcKk0mE9uXgi6e5EXGCLGGT lRSg== X-Received: by 10.15.31.197 with SMTP id y45mr51039716eeu.18.1366721505551; Tue, 23 Apr 2013 05:51:45 -0700 (PDT) Received: from [192.168.1.150] (AToulouse-654-1-479-219.w86-201.abo.wanadoo.fr. [86.201.194.219]) by mx.google.com with ESMTPS id b5sm46755056eew.16.2013.04.23.05.51.42 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Tue, 23 Apr 2013 05:51:44 -0700 (PDT) Message-ID: <517683DD.6060805@linaro.org> Date: Tue, 23 Apr 2013 14:51:41 +0200 From: Daniel Lezcano User-Agent: Mozilla/5.0 (X11; Linux i686; rv:17.0) Gecko/20130329 Thunderbird/17.0.5 MIME-Version: 1.0 To: Santosh Shilimkar CC: rjw@sisk.pl, andrew@lunn.ch, kgene.kim@samsung.com, jason@lakedaemon.net, horms@verge.net.au, patches@linaro.org, khilman@deeprootsystems.com, magnus.damm@gmail.com, linux-pm@vger.kernel.org, swarren@wwwdotorg.org, nsekhar@ti.com, rob.herring@calxeda.com, deepthi@linux.vnet.ibm.com, tony@atomide.com, lethal@linux-sh.org, linaro-kernel@lists.linaro.org, kernel@pengutronix.de, josephl@nvidia.com, jkosina@suse.cz, plagnioj@jcrosoft.com, linux@maxim.org.za, linux-arm-kernel@lists.infradead.org Subject: Re: [V4 patch 03/15] cpuidle: make a single register function for all References: <1366707285-12179-1-git-send-email-daniel.lezcano@linaro.org> <1366707285-12179-4-git-send-email-daniel.lezcano@linaro.org> <51767F57.7060809@ti.com> In-Reply-To: <51767F57.7060809@ti.com> X-Gm-Message-State: ALoCoQnsKotBEIyjKRjdpQFxAqaRlReFyomhlVg/39u/f2Mo2NMd/jLs/tGrNKqSQ4gHa1I3SZtT Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On 04/23/2013 02:32 PM, Santosh Shilimkar wrote: > On Tuesday 23 April 2013 02:24 PM, Daniel Lezcano wrote: >> The usual scheme to initialize a cpuidle driver on a SMP is: >> >> cpuidle_register_driver(drv); >> for_each_possible_cpu(cpu) { >> device = &per_cpu(cpuidle_dev, cpu); >> cpuidle_register_device(device); >> } >> >> This code is duplicated in each cpuidle driver. >> >> On UP systems, it is done this way: >> >> cpuidle_register_driver(drv); >> device = &per_cpu(cpuidle_dev, cpu); >> cpuidle_register_device(device); >> >> On UP, the macro 'for_each_cpu' does one iteration: >> >> #define for_each_cpu(cpu, mask) \ >> for ((cpu) = 0; (cpu) < 1; (cpu)++, (void)mask) >> >> Hence, the initialization loop is the same for UP than SMP. >> >> Beside, we saw different bugs / mis-initialization / return code unchecked in >> the different drivers, the code is duplicated including bugs. After fixing all >> these ones, it appears the initialization pattern is the same for everyone. >> >> Please note, some drivers are doing dev->state_count = drv->state_count. This is >> not necessary because it is done by the cpuidle_enable_device function in the >> cpuidle framework. This is true, until you have the same states for all your >> devices. Otherwise, the 'low level' API should be used instead with the specific >> initialization for the driver. >> >> Let's add a wrapper function doing this initialization with a cpumask parameter >> for the coupled idle states and use it for all the drivers. >> >> That will save a lot of LOC, consolidate the code, and the modifications in the >> future could be done in a single place. Another benefit is the consolidation of >> the cpuidle_device variable which is now in the cpuidle framework and no longer >> spread accross the different arch specific drivers. >> >> Signed-off-by: Daniel Lezcano >> --- > > I don't see you have addressed the comment on V3 [1] i gave for the subject patch > Any reason ? Yes, sorry for not answering. This modification should be handled in the __cpuidle_register_device function. per_cpu(cpuidle_devices, dev->cpu) = dev; Thus, the cpuidle_register function is not impacted by this as it will always do cpuidle_register_driver, followed by cpuidle_register_device. -- Daniel diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 49e8d30..936d862 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -372,7 +372,7 @@ static int __cpuidle_register_device(struct cpuidle_device *dev) int ret; struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); - if (!try_module_get(drv->owner)) + if (!drv || !try_module_get(drv->owner)) return -EINVAL;