From patchwork Mon Jan 11 17:35:57 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Juri Lelli X-Patchwork-Id: 8007331 Return-Path: X-Original-To: patchwork-linux-pm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 6B5FD9F1C0 for ; Mon, 11 Jan 2016 17:38:46 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 8AF9D20256 for ; Mon, 11 Jan 2016 17:38:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7E43F201EC for ; Mon, 11 Jan 2016 17:38:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761294AbcAKRhr (ORCPT ); Mon, 11 Jan 2016 12:37:47 -0500 Received: from foss.arm.com ([217.140.101.70]:57295 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761293AbcAKRhp (ORCPT ); Mon, 11 Jan 2016 12:37:45 -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 364205EE; Mon, 11 Jan 2016 09:37:10 -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 2C99E3F24D; Mon, 11 Jan 2016 09:37:43 -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 16/19] cpufreq: hold policy->rwsem across CPUFREQ_GOV_POLICY_EXIT Date: Mon, 11 Jan 2016 17:35:57 +0000 Message-Id: <1452533760-13787-17-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 There are no good reasons why policy->rwsem cannot be hold across calls to __cpufreq_governor with CPUFREQ_GOV_POLICY_EXIT event. Remove {up,down}_write across such call sites. This also verify assertion that policy->rwsem is always hold when calling into __cpufreq_governor. Cc: "Rafael J. Wysocki" Cc: Viresh Kumar Signed-off-by: Juri Lelli --- drivers/cpufreq/cpufreq.c | 4 ---- include/linux/cpufreq.h | 4 ---- 2 files changed, 8 deletions(-) diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index d58a622..797bfae 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -2182,9 +2182,7 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, return ret; } - up_write(&policy->rwsem); ret = __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); - down_write(&policy->rwsem); if (ret) { pr_err("%s: Failed to Exit Governor: %s (%d)\n", @@ -2201,9 +2199,7 @@ static int cpufreq_set_policy(struct cpufreq_policy *policy, if (!ret) goto out; - up_write(&policy->rwsem); __cpufreq_governor(policy, CPUFREQ_GOV_POLICY_EXIT); - down_write(&policy->rwsem); } /* new governor failed, so re-start old one */ diff --git a/include/linux/cpufreq.h b/include/linux/cpufreq.h index 88a4215..79b87ce 100644 --- a/include/linux/cpufreq.h +++ b/include/linux/cpufreq.h @@ -100,10 +100,6 @@ struct cpufreq_policy { * - Any routine that will write to the policy structure and/or may take away * the policy altogether (eg. CPU hotplug), will hold this lock in write * mode before doing so. - * - * Additional rules: - * - Lock should not be held across - * __cpufreq_governor(data, CPUFREQ_GOV_POLICY_EXIT); */ struct rw_semaphore rwsem;