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[2620:137:e000::1:20]) by mx.google.com with ESMTP id j14-20020a05640211ce00b00456eaa4fb1fsi1785327edw.223.2022.11.17.13.16.26; Thu, 17 Nov 2022 13:17:13 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240580AbiKQVMG (ORCPT + 99 others); Thu, 17 Nov 2022 16:12:06 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56946 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240736AbiKQVL5 (ORCPT ); Thu, 17 Nov 2022 16:11:57 -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 7C7DE22283 for ; Thu, 17 Nov 2022 13:11:56 -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 1ovmAp-0007On-Uh; Thu, 17 Nov 2022 22:11:52 +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 1ovmAo-004v5m-6M; Thu, 17 Nov 2022 22:11:51 +0100 Received: from ukl by ptz.office.stw.pengutronix.de with local (Exim 4.94.2) (envelope-from ) id 1ovmAo-00HN0F-Dh; Thu, 17 Nov 2022 22:11:50 +0100 From: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= To: Thierry Reding Cc: linux-pwm@vger.kernel.org, Andy Shevchenko , linux-kernel@vger.kernel.org, kernel@pengutronix.de Subject: [PATCH v2 1/4] pwm: Document variables protected by pwm_lock Date: Thu, 17 Nov 2022 22:11:40 +0100 Message-Id: <20221117211143.3817381-2-u.kleine-koenig@pengutronix.de> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221117211143.3817381-1-u.kleine-koenig@pengutronix.de> References: <20221117211143.3817381-1-u.kleine-koenig@pengutronix.de> MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1336; i=u.kleine-koenig@pengutronix.de; h=from:subject; bh=gVppIEf/lpbSlfN4FOCkWayRJhongp4knJTqk4NtP9Q=; b=owEBbQGS/pANAwAKAcH8FHityuwJAcsmYgBjdqN+8HG4Bay2je5Xh/cc1bSrfdvdcwF88fPwunKV FGDfVEKJATMEAAEKAB0WIQR+cioWkBis/z50pAvB/BR4rcrsCQUCY3ajfgAKCRDB/BR4rcrsCZV5B/ 9+W4jlFDJayYkJPKxcszuItsiylo7wpidxU8YNXE9cYbwpw9aXu/eJ8gOOAjfs5i6/+QoofiLTTGkt 5CYqgvRLMpgvNir2eQKwgkINkJIvlzJQUzmnTTFJeTbpgi/RgfHDUszIXPQyEbgCXAXMDgiLo4UUBr c5kcgAICd0yyNvgELU6yXEzSvrUTNx3AXKzIhCl+Xsd81KTD/thUy6CqvlVYwEN3AAdlMs37u1lwkU cbsGobvw+yqbpoVuZ3+RHpOEZuyx+vjQ5VBsWSbLoKiFlxngfmULjIYCVWHfXVTBaLcl3ygzE/Y5ja Ieu0+bMI2x6YndkGlNKIHmqZPv+XNh 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-kernel@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=unavailable 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-kernel@vger.kernel.org X-getmail-retrieved-from-mailbox: =?utf-8?q?INBOX?= X-GMAIL-THRID: =?utf-8?q?1749779567822581624?= X-GMAIL-MSGID: =?utf-8?q?1749779567822581624?= 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. Reviewed-by: Andy Shevchenko Signed-off-by: Uwe Kleine-König --- 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;