From patchwork Mon Jan 11 17:35:43 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Juri Lelli X-Patchwork-Id: 8007551 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id CD037BEEE5 for ; Mon, 11 Jan 2016 17:42:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id E1C0320256 for ; Mon, 11 Jan 2016 17:42:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 07204201FE for ; Mon, 11 Jan 2016 17:42:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760036AbcAKRhQ (ORCPT ); Mon, 11 Jan 2016 12:37:16 -0500 Received: from foss.arm.com ([217.140.101.70]:57214 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758586AbcAKRhP (ORCPT ); Mon, 11 Jan 2016 12:37:15 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6126C5E9; Mon, 11 Jan 2016 09:36:40 -0800 (PST) Received: from e106622-lin.cambridge.arm.com (e106622-lin.cambridge.arm.com [10.1.208.152]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 557673F24D; Mon, 11 Jan 2016 09:37:13 -0800 (PST) From: Juri Lelli To: linux-kernel@vger.kernel.org Cc: linux-pm@vger.kernel.org, peterz@infradead.org, rjw@rjwysocki.net, viresh.kumar@linaro.org, mturquette@baylibre.com, steve.muckle@linaro.org, vincent.guittot@linaro.org, morten.rasmussen@arm.com, dietmar.eggemann@arm.com, juri.lelli@arm.com Subject: [RFC PATCH 02/19] cpufreq: merge governor lock and mutex Date: Mon, 11 Jan 2016 17:35:43 +0000 Message-Id: <1452533760-13787-3-git-send-email-juri.lelli@arm.com> X-Mailer: git-send-email 2.2.2 In-Reply-To: <1452533760-13787-1-git-send-email-juri.lelli@arm.com> References: <1452533760-13787-1-git-send-email-juri.lelli@arm.com> Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Michael Turquette Commit 95731ebb114c ("cpufreq: Fix governor start/stop race condition") introduced cpufreq_governor_lock. This was actually overkilling, as the same can be achieved by using the existing cpufreq_governor_mutex. Removing cpufreq_governor_lock cleans things up and makes deadlocks less likely to happen. Cc: "Rafael J. Wysocki" Cc: Viresh Kumar Signed-off-by: Michael Turquette Acked-by: Viresh Kumar --- drivers/cpufreq/cpufreq.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index 7bdd845..0802705 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -102,7 +102,7 @@ static LIST_HEAD(cpufreq_governor_list); static struct cpufreq_driver *cpufreq_driver; static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); static DEFINE_RWLOCK(cpufreq_driver_lock); -static DEFINE_MUTEX(cpufreq_governor_lock); +static DEFINE_MUTEX(cpufreq_governor_mutex); /* Flag to suspend/resume CPUFreq governors */ static bool cpufreq_suspended; @@ -146,7 +146,6 @@ void disable_cpufreq(void) { off = 1; } -static DEFINE_MUTEX(cpufreq_governor_mutex); bool have_governor_per_policy(void) { @@ -1963,11 +1962,11 @@ static int __cpufreq_governor(struct cpufreq_policy *policy, pr_debug("%s: for CPU %u, event %u\n", __func__, policy->cpu, event); - mutex_lock(&cpufreq_governor_lock); + mutex_lock(&cpufreq_governor_mutex); if ((policy->governor_enabled && event == CPUFREQ_GOV_START) || (!policy->governor_enabled && (event == CPUFREQ_GOV_LIMITS || event == CPUFREQ_GOV_STOP))) { - mutex_unlock(&cpufreq_governor_lock); + mutex_unlock(&cpufreq_governor_mutex); return -EBUSY; } @@ -1976,7 +1975,7 @@ static int __cpufreq_governor(struct cpufreq_policy *policy, else if (event == CPUFREQ_GOV_START) policy->governor_enabled = true; - mutex_unlock(&cpufreq_governor_lock); + mutex_unlock(&cpufreq_governor_mutex); ret = policy->governor->governor(policy, event); @@ -1987,12 +1986,12 @@ static int __cpufreq_governor(struct cpufreq_policy *policy, policy->governor->initialized--; } else { /* Restore original values */ - mutex_lock(&cpufreq_governor_lock); + mutex_lock(&cpufreq_governor_mutex); if (event == CPUFREQ_GOV_STOP) policy->governor_enabled = true; else if (event == CPUFREQ_GOV_START) policy->governor_enabled = false; - mutex_unlock(&cpufreq_governor_lock); + mutex_unlock(&cpufreq_governor_mutex); } if (((event == CPUFREQ_GOV_POLICY_INIT) && ret) ||