From patchwork Tue May 12 06:41:58 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Krzysztof Kozlowski X-Patchwork-Id: 212059 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.3 required=3.0 tests=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id B0116C54E4B for ; Tue, 12 May 2020 06:42:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 86CF720733 for ; Tue, 12 May 2020 06:42:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589265729; bh=/twyJJ9dZnGQh92dBReEWJHuGeydxSxiQp7BLmW7c7o=; h=From:To:Cc:Subject:Date:List-ID:From; b=qxtPI7E3UfvQ4PSC324pDmTEXbcx/83MsPOkj6TwouXIVXL9rDAGRhvA3eIuTqB5Z ATi1YtwMXgns2xU45t3/bwPAYfWEVa/M0fbD26RORYoiH0oNwJUnPf7kIMKSYf2iXv sk80spFcP234fP+oplCbMpOliUmVs34tP3b+DZIc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725933AbgELGmI (ORCPT ); Tue, 12 May 2020 02:42:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:45632 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725536AbgELGmI (ORCPT ); Tue, 12 May 2020 02:42:08 -0400 Received: from kozik-lap.mshome.net (unknown [194.230.155.237]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AE03B20575; Tue, 12 May 2020 06:42:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589265728; bh=/twyJJ9dZnGQh92dBReEWJHuGeydxSxiQp7BLmW7c7o=; h=From:To:Cc:Subject:Date:From; b=taEzXckUt0vlcJ9f68oz31J364YSwNW5+KCBizpQ4D4/vsC34fDLCcLBk7STZEc/F HyNU4ON4ZTdftIASirnYBNZHzkM0WcuNsi5YP3/kUJbMLARc3piOna09c6+XrbeLTM gahpFbWGga3D8ejRHtplh60Zq23alEdJbzz/+yWk= From: Krzysztof Kozlowski To: MyungJoo Ham , Kyungmin Park , Chanwoo Choi , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Krzysztof Kozlowski Subject: [PATCH] devfreq: Use lockdep asserts instead of manual checks for locked mutex Date: Tue, 12 May 2020 08:41:58 +0200 Message-Id: <20200512064158.7957-1-krzk@kernel.org> X-Mailer: git-send-email 2.17.1 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Instead of warning when mutex_is_locked(), just use the lockdep framework. The code is smaller and checks could be disabled for production environments (it is useful only during development). Put asserts at beginning of function, even before validating arguments. The behavior of update_devfreq() is now changed because lockdep assert will only print a warning, not return with EINVAL. Signed-off-by: Krzysztof Kozlowski --- drivers/devfreq/devfreq.c | 17 +++++++---------- 1 file changed, 7 insertions(+), 10 deletions(-) diff --git a/drivers/devfreq/devfreq.c b/drivers/devfreq/devfreq.c index ef3d2bc3d1ac..52b9c3e141f3 100644 --- a/drivers/devfreq/devfreq.c +++ b/drivers/devfreq/devfreq.c @@ -60,12 +60,12 @@ static struct devfreq *find_device_devfreq(struct device *dev) { struct devfreq *tmp_devfreq; + lockdep_assert_held(&devfreq_list_lock); + if (IS_ERR_OR_NULL(dev)) { pr_err("DEVFREQ: %s: Invalid parameters\n", __func__); return ERR_PTR(-EINVAL); } - WARN(!mutex_is_locked(&devfreq_list_lock), - "devfreq_list_lock must be locked."); list_for_each_entry(tmp_devfreq, &devfreq_list, node) { if (tmp_devfreq->dev.parent == dev) @@ -258,12 +258,12 @@ static struct devfreq_governor *find_devfreq_governor(const char *name) { struct devfreq_governor *tmp_governor; + lockdep_assert_held(&devfreq_list_lock); + if (IS_ERR_OR_NULL(name)) { pr_err("DEVFREQ: %s: Invalid parameters\n", __func__); return ERR_PTR(-EINVAL); } - WARN(!mutex_is_locked(&devfreq_list_lock), - "devfreq_list_lock must be locked."); list_for_each_entry(tmp_governor, &devfreq_governor_list, node) { if (!strncmp(tmp_governor->name, name, DEVFREQ_NAME_LEN)) @@ -289,12 +289,12 @@ static struct devfreq_governor *try_then_request_governor(const char *name) struct devfreq_governor *governor; int err = 0; + lockdep_assert_held(&devfreq_list_lock); + if (IS_ERR_OR_NULL(name)) { pr_err("DEVFREQ: %s: Invalid parameters\n", __func__); return ERR_PTR(-EINVAL); } - WARN(!mutex_is_locked(&devfreq_list_lock), - "devfreq_list_lock must be locked."); governor = find_devfreq_governor(name); if (IS_ERR(governor)) { @@ -392,10 +392,7 @@ int update_devfreq(struct devfreq *devfreq) int err = 0; u32 flags = 0; - if (!mutex_is_locked(&devfreq->lock)) { - WARN(true, "devfreq->lock must be locked by the caller.\n"); - return -EINVAL; - } + lockdep_assert_held(&devfreq->lock); if (!devfreq->governor) return -EINVAL;