Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756998Ab3GKWTS (ORCPT ); Thu, 11 Jul 2013 18:19:18 -0400 Received: from e23smtp07.au.ibm.com ([202.81.31.140]:41766 "EHLO e23smtp07.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756887Ab3GKWTQ (ORCPT ); Thu, 11 Jul 2013 18:19:16 -0400 From: "Srivatsa S. Bhat" Subject: [PATCH 1/8] cpufreq: Revert commit a66b2e to fix cpufreq regression during suspend/resume To: rjw@sisk.pl, viresh.kumar@linaro.org, toralf.foerster@gmx.de, robert.jarzmik@intel.com, durgadoss.r@intel.com, tianyu.lan@intel.com, lantianyu1986@gmail.com, dirk.brandewie@gmail.com Cc: stern@rowland.harvard.edu, "Srivatsa S. Bhat" , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Date: Fri, 12 Jul 2013 03:45:37 +0530 Message-ID: <20130711221527.547.46447.stgit@srivatsabhat.in.ibm.com> In-Reply-To: <20130711221419.547.69781.stgit@srivatsabhat.in.ibm.com> References: <20130711221419.547.69781.stgit@srivatsabhat.in.ibm.com> User-Agent: StGIT/0.14.3 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit X-Content-Scanned: Fidelis XPS MAILER x-cbid: 13071122-0260-0000-0000-0000034C43C9 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3161 Lines: 82 commit a66b2e (cpufreq: Preserve sysfs files across suspend/resume) has unfortunately caused several things in the cpufreq subsystem to break subtly after a suspend/resume cycle. The intention of that patch was to retain the file permissions of the cpufreq related sysfs files across suspend/resume. To achieve that, the commit completely removed the calls to cpufreq_add_dev() and __cpufreq_remove_dev() during suspend/resume transitions. But the problem is that those functions do 2 kinds of things: 1. Low-level initialization/tear-down that are critical to the correct functioning of cpufreq-core. 2. Kobject and sysfs related initialization/teardown. Ideally we should have reorganized the code to cleanly separate these two responsibilities, and skipped only the sysfs related parts during suspend/resume. Since we skipped the entire callbacks instead (which also included some CPU and cpufreq-specific critical components), cpufreq subsystem started behaving erratically after suspend/resume. So revert the commit to fix the regression. We'll revisit and address the original goal of that commit separately, since it involves quite a bit of careful code reorganization and appears to be non-trivial. (While reverting the commit, note that another commit f51e1eb "cpufreq: Fix cpufreq regression after suspend/resume" already reverted part of the original set of changes. So revert only the remaining ones). Cc: stable@vger.kernel.org Signed-off-by: Srivatsa S. Bhat --- drivers/cpufreq/cpufreq.c | 4 +++- drivers/cpufreq/cpufreq_stats.c | 6 ++---- 2 files changed, 5 insertions(+), 5 deletions(-) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 6a015ad..ccc6eab 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -1941,13 +1941,15 @@ static int __cpuinit cpufreq_cpu_callback(struct notifier_block *nfb, if (dev) { switch (action) { case CPU_ONLINE: + case CPU_ONLINE_FROZEN: cpufreq_add_dev(dev, NULL); break; case CPU_DOWN_PREPARE: - case CPU_UP_CANCELED_FROZEN: + case CPU_DOWN_PREPARE_FROZEN: __cpufreq_remove_dev(dev, NULL); break; case CPU_DOWN_FAILED: + case CPU_DOWN_FAILED_FROZEN: cpufreq_add_dev(dev, NULL); break; } diff --git a/drivers/cpufreq/cpufreq_stats.c b/drivers/cpufreq/cpufreq_stats.c index cd9e817..12225d1 100644 --- a/drivers/cpufreq/cpufreq_stats.c +++ b/drivers/cpufreq/cpufreq_stats.c @@ -353,13 +353,11 @@ static int __cpuinit cpufreq_stat_cpu_callback(struct notifier_block *nfb, cpufreq_update_policy(cpu); break; case CPU_DOWN_PREPARE: + case CPU_DOWN_PREPARE_FROZEN: cpufreq_stats_free_sysfs(cpu); break; case CPU_DEAD: - cpufreq_stats_free_table(cpu); - break; - case CPU_UP_CANCELED_FROZEN: - cpufreq_stats_free_sysfs(cpu); + case CPU_DEAD_FROZEN: cpufreq_stats_free_table(cpu); break; } -- 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/