From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754204Ab3KZGtX (ORCPT ); Tue, 26 Nov 2013 01:49:23 -0500 Received: from mga02.intel.com ([134.134.136.20]:24925 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752117Ab3KZGtV (ORCPT ); Tue, 26 Nov 2013 01:49:21 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.93,772,1378882800"; d="scan'208";a="414901710" Message-ID: <529441B7.90505@intel.com> Date: Tue, 26 Nov 2013 14:37:43 +0800 From: Lan Tianyu User-Agent: Mozilla/5.0 (X11; Linux i686; rv:14.0) Gecko/20120714 Thunderbird/14.0 MIME-Version: 1.0 To: Viresh Kumar CC: rjw@rjwysocki.net, linaro-kernel@lists.linaro.org, patches@linaro.org, cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, nm@ti.com, swarren@wwwdotorg.org, kgene.kim@samsung.com, linux-samsung-soc@vger.kernel.org, linux-tegra@vger.kernel.org, jinchoi@broadcom.com, sebastian.capella@linaro.org, jhbird.choi@samsung.com Subject: Re: [PATCH V3 0/6] cpufreq: suspend early/resume late References: In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2013年11月25日 22:11, Viresh Kumar wrote: > This patchset adds cpufreq callbacks to dpm_{suspend|resume}() for handling > suspend/resume of cpufreq governors and core. This is required for early suspend > and late resume of governors and cpufreq core. > > There are multiple problems that are fixed by this patch: > - Nishanth Menon (TI) found an interesting problem on his platform, OMAP. His board > wasn't working well with suspend/resume as calls for removing non-boot CPUs > was turning out into a call to drivers ->target() which then tries to play > with regulators. But regulators and their I2C bus were already suspended and > this resulted in a failure. Many platforms have such problems, samsung, tegra, > etc.. They solved it with driver specific PM notifiers where they used to > disable their driver's ->target() routine. Most of these are updated in this > patchset to use new infrastructure. > > - Lan Tianyu (Intel) & Jinhyuk Choi (Broadcom) found another issue where > tunables configuration for clusters/sockets with non-boot CPUs was getting > lost after suspend/resume, as we were notifying governors with > CPUFREQ_GOV_POLICY_EXIT on removal of the last cpu for that policy and so > deallocating memory for tunables. This is also fixed with this patch as don't > allow any operation on Governors during suspend/resume now. > > > So to solve these issues we introduce early suspend and late resume callbacks > which would remove need of cpufreq drivers to implement PM notifiers to disable > transition after suspend and before resume. > > @Nishanth: Can you please test V2 as well and confirm that suspend_noirq() > doesn't work for you. I am sure it will not, but would be better if you confirm > that. > > Viresh Kumar (6): > cpufreq: suspend governors on system suspend/hibernate > cpufreq: call driver's suspend/resume for each policy > cpufreq: Implement cpufreq_generic_suspend() > cpufreq: exynos: Use cpufreq_generic_suspend() > cpufreq: s5pv210: Use cpufreq_generic_suspend() > cpufreq: Tegra: Use cpufreq_generic_suspend() > Patch 1-2, Tested-by: Lan Tianyu > drivers/base/power/main.c | 5 ++ > drivers/cpufreq/cpufreq.c | 133 +++++++++++++++++++++----------------- > drivers/cpufreq/exynos-cpufreq.c | 97 ++------------------------- > drivers/cpufreq/s5pv210-cpufreq.c | 49 +------------- > drivers/cpufreq/tegra-cpufreq.c | 54 ++-------------- > include/linux/cpufreq.h | 6 ++ > 6 files changed, 99 insertions(+), 245 deletions(-) > -- Best regards Tianyu Lan