From patchwork Wed Jan 25 22:31:34 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Arnd Bergmann X-Patchwork-Id: 719906 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3v80DH2SNdz9s2Q for ; Thu, 26 Jan 2017 09:32:31 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752136AbdAYWca (ORCPT ); Wed, 25 Jan 2017 17:32:30 -0500 Received: from mout.kundenserver.de ([212.227.126.135]:53894 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752106AbdAYWc3 (ORCPT ); Wed, 25 Jan 2017 17:32:29 -0500 Received: from wuerfel.lan ([78.43.21.235]) by mrelayeu.kundenserver.de (mreue002 [212.227.15.129]) with ESMTPA (Nemesis) id 0LmzQD-1c0VCV1sqr-00hOQO; Wed, 25 Jan 2017 23:31:58 +0100 From: Arnd Bergmann To: Thierry Reding Cc: Arnd Bergmann , Maxime Coquelin , Alexandre Torgue , Lee Jones , Benjamin Gaignard , linux-pwm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: [PATCH] pwm: fix undefined behavior in stm32_pwm_apply Date: Wed, 25 Jan 2017 23:31:34 +0100 Message-Id: <20170125223155.1388582-1-arnd@arndb.de> X-Mailer: git-send-email 2.9.0 X-Provags-ID: V03:K0:FO6OllYl//we314xcIoe94bZUcy99Y1WeusiHks8rbqJvYX6Nz4 z8O58wbuVT2hmlr6IVw1j9HoLsPFiSYN6pQYWK9MKrBKPqZz+1M1hbwoymyz93DBAmU4vXj vJ3sjU3NHOLVEZFaWlxojcUW9gx18e14OPqdjsjJQ3CRwvEOAlAvUZKF0jBEImeo8K7Me+f 1jxxFKBlBS2VnHE6A7SMw== X-UI-Out-Filterresults: notjunk:1; V01:K0:3uZbC36bKug=:ypmg8+858abkPbNE4wa+lU KfsGTd3DEOaXcZyhZeqOZ1lkQgNiRCwJD1Mh8qkbljFeIhiEje6/SmO7AzhjXeot0bDGsHAQS IPgHMrp7bExFPdLBGhLVmejQqzDclF63jTgi+AGkhkv/4EubgDwnYwURgF8JwmNopIyZ+7CQ/ I8yWCyaaGlFN4DLR9ClCAKjgD+ioxoD63VVxBwoZFgXB/U8JJv+ZnAddoriNrUORK8TFnrSRq j2f9zd8+Q2NqV1sCfPW6sr2e52kr8JXpS6nBRKYxXc8BJbvfFWK+62zhJVsoSW42NNAcnVrZe 1q0RLalQEKSMl47o+Fq0k8pCXv8DIbmLrkesGQxEV59/DT0/DnsrTp58G3olKZj0aERZcNUiK Gt8bwR5Lutbax/MbmDdZiRlnsryFk9A6/binz5I4DKftC4A0aEKo46XYappyYFiFlJid0fCnM AiEdnGk+V/aQsqp12P+NKd6G6hlVIXE+HbJZsY2RNqTKgzvKvkyW4hqS7//hbqxWFB8ItVMrs 096bcud/Q+Y5zb0bz4SAfLveK6DoWvXq0zJL9HrmmcVUpyOz+oQePZfaMRODEFRwLoUJQF7Gc 5la0Kcyi0zLuOc1mZCEsGCMsINXyPaxHE2ofpeLmDeMF18yNwUnc0hQy3g0mum3enruL/zHB4 g4Bd17txY44u9kvNHuUHFk06prfxpKSF7SCqbJNdej0s4YTCl/O3OGbkbroqjLNnrAVg= Sender: linux-pwm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pwm@vger.kernel.org The stm32_pwm_apply randomly sets the polarity or doesn't, as pointed out by this gcc warning: drivers/pwm/pwm-stm32.c: In function 'stm32_pwm_apply': drivers/pwm/pwm-stm32.c:204:33: error: 'curstate.polarity' may be used uninitialized in this function [-Werror=maybe-uninitialized] I assume it was meant to compare the new state to the current state rather than an uninitialized stack variable, so let's do that instead. Fixes: bafffb6e7bd1 ("pwm: Add driver for STM32 plaftorm") Signed-off-by: Arnd Bergmann --- drivers/pwm/pwm-stm32.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/pwm/pwm-stm32.c b/drivers/pwm/pwm-stm32.c index ce6232ebefe1..6139512aab7b 100644 --- a/drivers/pwm/pwm-stm32.c +++ b/drivers/pwm/pwm-stm32.c @@ -189,7 +189,6 @@ static void stm32_pwm_disable(struct stm32_pwm *priv, int ch) static int stm32_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, struct pwm_state *state) { - struct pwm_state curstate; bool enabled; struct stm32_pwm *priv = to_stm32_pwm_dev(chip); int ret; @@ -201,7 +200,7 @@ static int stm32_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, return 0; } - if (state->polarity != curstate.polarity) + if (state->polarity != pwm->state.polarity) stm32_pwm_set_polarity(priv, pwm->hwpwm, state->polarity); ret = stm32_pwm_config(priv, pwm->hwpwm,