Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758790AbcC3IlP (ORCPT ); Wed, 30 Mar 2016 04:41:15 -0400 Received: from mail-wm0-f41.google.com ([74.125.82.41]:34679 "EHLO mail-wm0-f41.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753892AbcC3IlM (ORCPT ); Wed, 30 Mar 2016 04:41:12 -0400 Subject: Re: [PATCH 1/2] ARM: cpuidle: fix !cpuidle_ops[cpu].init case during init To: Jisheng Zhang , Lorenzo Pieralisi , Catalin Marinas References: <1458796269-6158-1-git-send-email-jszhang@marvell.com> <1458796269-6158-2-git-send-email-jszhang@marvell.com> <56F52502.3060308@linaro.org> <20160330151629.0b338365@xhacker> <56FB89A8.90209@linaro.org> <20160330161745.7afd6e48@xhacker> Cc: linux@arm.linux.org.uk, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org From: Daniel Lezcano Message-ID: <56FB9125.10507@linaro.org> Date: Wed, 30 Mar 2016 10:41:09 +0200 User-Agent: Mozilla/5.0 (X11; Linux i686; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <20160330161745.7afd6e48@xhacker> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1500 Lines: 44 On 03/30/2016 10:17 AM, Jisheng Zhang wrote: > On Wed, 30 Mar 2016 10:09:12 +0200 Daniel Lezcano wrote: > >> On 03/30/2016 09:16 AM, Jisheng Zhang wrote: >>> Hi Daniel, >> >> [ ... ] >> >> Added Lorenzo and Catalin. >> >>>> Hi Jisheng, >>>> >>>> this should be handled in the arm_cpuidle_read_ops function. >>>> >>> >>> Thanks for reviewing. After some consideration, I think this patch isn't correct >>> There may be platforms which doesn't need the init member at all, although >>> currently I don't see such platforms in mainline, So I'll drop this patch >>> and send out one v2 only does the optimization. >> >> There is an inconsistency between ARM and ARM64. The 'cpu_get_ops', the >> arm_cpuidle_read_ops from the ARM64 side, returns -EOPNOTSUPP when the >> init function is not there for cpuidle. > > yes. > arm64's arm_cpuidle_init() returns -EOPNOTSUPP if init callback isn't defined > >> >> I don't think it is a problem, but as ARM/ARM64 are sharing the same >> cpuidle-arm.c driver it would make sense to unify the behavior between >> both archs. > > yes, agree with you. From "unify" point of view, could I move back the suspend > callback check and init callback check into arm_cpuidle_init() for arm as V1 does? Why ? To be consistent with ARM64 ? -- Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog