From patchwork Tue Nov 15 21:15:12 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= X-Patchwork-Id: 1704240 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=linux-pwm-owner@vger.kernel.org; receiver=) Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by legolas.ozlabs.org (Postfix) with ESMTP id 4NBf974L6Lz20KC for ; Wed, 16 Nov 2022 08:15:39 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231356AbiKOVPg (ORCPT ); Tue, 15 Nov 2022 16:15:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42796 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231159AbiKOVPf (ORCPT ); Tue, 15 Nov 2022 16:15:35 -0500 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 12C98D2C4 for ; Tue, 15 Nov 2022 13:15:35 -0800 (PST) Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ov3HJ-0005Bm-2P; Tue, 15 Nov 2022 22:15:33 +0100 Received: from [2a0a:edc0:0:900:1d::77] (helo=ptz.office.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtp (Exim 4.94.2) (envelope-from ) id 1ov3HH-004WcK-0s; Tue, 15 Nov 2022 22:15:31 +0100 Received: from ukl by ptz.office.stw.pengutronix.de with local (Exim 4.94.2) (envelope-from ) id 1ov3HH-00Guk2-30; Tue, 15 Nov 2022 22:15:31 +0100 From: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= To: Thierry Reding Cc: Andy Shevchenko , linux-pwm@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@pengutronix.de Subject: [PATCH 1/4] pwm: Document variables protected by pwm_lock Date: Tue, 15 Nov 2022 22:15:12 +0100 Message-Id: <20221115211515.3750209-2-u.kleine-koenig@pengutronix.de> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221115211515.3750209-1-u.kleine-koenig@pengutronix.de> References: <20221115211515.3750209-1-u.kleine-koenig@pengutronix.de> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1270; i=u.kleine-koenig@pengutronix.de; h=from:subject; bh=mqv6t9UGVbAo+3D4RTnRLJH+fYTyOfUpbMDUQ3lKzxk=; b=owEBbQGS/pANAwAKAcH8FHityuwJAcsmYgBjdAFWIm6NA6nU04xY7TzqbfgU2WSxJpL3FVVw23km z0yS0eCJATMEAAEKAB0WIQR+cioWkBis/z50pAvB/BR4rcrsCQUCY3QBVgAKCRDB/BR4rcrsCTxHB/ 9vZtRKS7LBMrGXgzFQUembNvZGGIrWV43Jdms8msbvx3Zzf2T/Doh7Cs63zbJootocGvc0Kb6D+/Zp FtnoFymGBV9PVk7j3qZuvG4TcjSu2VWLBicAWIy3VUcAsb4xcPZoSBVZwHiR6ZP+nHp3BoFanz1Pyr PkHVhG4TtkZa7Mv82kZmjdyyj2MRlUL/HQBostGvNxWe/8fuDVtsZJUtI/rS0BW6eY3wUymSRTTQ/M JMxmDWrOAylJ+OttJEyZD/by9pQ9gZrdl7LkYwgKSKGUCdVM8gUXb0lTpacEN8FwlvAas/8HIb1En3 vQsVPBZG9NgkX1e6y6Utaek0PXbquS X-Developer-Key: i=u.kleine-koenig@pengutronix.de; a=openpgp; fpr=0D2511F322BFAB1C1580266BE2DCDD9132669BD6 X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-pwm@vger.kernel.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00,RCVD_IN_DNSWL_MED, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-pwm@vger.kernel.org To simplify validation of the used locking, document for the global pwm mutex what it actually protects against concurrent access. Also note for two functions modifying these that pwm_lock is held by the caller. Signed-off-by: Uwe Kleine-König Reviewed-by: Andy Shevchenko --- drivers/pwm/core.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index d333e7422f4a..ebe06efe9de5 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -27,7 +27,10 @@ static DEFINE_MUTEX(pwm_lookup_lock); static LIST_HEAD(pwm_lookup_list); + +/* protects access to pwm_chips, allocated_pwms, and pwm_tree */ static DEFINE_MUTEX(pwm_lock); + static LIST_HEAD(pwm_chips); static DECLARE_BITMAP(allocated_pwms, MAX_PWMS); static RADIX_TREE(pwm_tree, GFP_KERNEL); @@ -37,6 +40,7 @@ static struct pwm_device *pwm_to_device(unsigned int pwm) return radix_tree_lookup(&pwm_tree, pwm); } +/* Called with pwm_lock held */ static int alloc_pwms(unsigned int count) { unsigned int start; @@ -50,6 +54,7 @@ static int alloc_pwms(unsigned int count) return start; } +/* Called with pwm_lock held */ static void free_pwms(struct pwm_chip *chip) { unsigned int i;