From patchwork Mon Aug 1 22:01:32 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Robert Jarzmik X-Patchwork-Id: 9254927 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 6F5A86077C for ; Mon, 1 Aug 2016 22:03:45 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 5CF4428466 for ; Mon, 1 Aug 2016 22:03:45 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4FC30284A6; Mon, 1 Aug 2016 22:03:45 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00,FREEMAIL_FROM, RCVD_IN_DNSWL_MED autolearn=unavailable version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id CB46D28466 for ; Mon, 1 Aug 2016 22:03:44 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bULHi-00042x-Mb; Mon, 01 Aug 2016 22:02:06 +0000 Received: from smtp13.smtpout.orange.fr ([80.12.242.135] helo=smtp.smtpout.orange.fr) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bULHf-0003ze-AD for linux-arm-kernel@lists.infradead.org; Mon, 01 Aug 2016 22:02:04 +0000 Received: from belgarion.home ([86.199.194.242]) by mwinf5d74 with ME id Ry1b1t00A5EFnam03y1bZm; Tue, 02 Aug 2016 00:01:40 +0200 X-ME-Helo: belgarion.home X-ME-Date: Tue, 02 Aug 2016 00:01:40 +0200 X-ME-IP: 86.199.194.242 From: Robert Jarzmik To: Daniel Mack , Haojian Zhuang , Robert Jarzmik , Russell King Subject: [PATCH v4] ARM: pxa: fix GPIO double shifts Date: Tue, 2 Aug 2016 00:01:32 +0200 Message-Id: <1470088892-31373-1-git-send-email-robert.jarzmik@free.fr> X-Mailer: git-send-email 2.1.4 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160801_150203_812326_EEF491EF X-CRM114-Status: GOOD ( 15.07 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Joe Perches , linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP The commit 9bf448c66d4b ("ARM: pxa: use generic gpio operation instead of gpio register") from Oct 17, 2011, leads to the following static checker warning: arch/arm/mach-pxa/spitz_pm.c:172 spitz_charger_wakeup() warn: double left shift '!gpio_get_value(SPITZ_GPIO_KEY_INT) << (1 << ((SPITZ_GPIO_KEY_INT) & 31))' As Dan reported, the value is shifted three times : - once by gpio_get_value(), which returns either 0 or BIT(gpio) - once by the shift operation '<<' - a last time by GPIO_bit(gpio) which is BIT(gpio) Therefore the calculation lead to a chained or operator of : - (1 << gpio) << (1 << gpio) = (2^gpio)^gpio = 2 ^ (gpio * gpio) It is be sheer luck the former statement works, only because each gpio used is strictly smaller than 6, and therefore 2^(gpio^2) never overflows a 32 bits value, and because it is used as a boolean value to check a gpio activation. As the xxx_charger_wakeup() functions are used as a true/false detection mechanism, take that opportunity to change their prototypes from integer return value to boolean one. Fixes: 9bf448c66d4b ("ARM: pxa: use generic gpio operation instead of gpio register") Reported-by: Dan Carpenter Cc: Joe Perches Signed-off-by: Robert Jarzmik --- Since v1: replaced binary ORs with logical ORs after assembly comparison Since v2: changed charger_wakeup prototype to bool foo() Since v3: direct return statements in xxx_charger_wakeup() --- arch/arm/mach-pxa/corgi_pm.c | 13 ++++--------- arch/arm/mach-pxa/sharpsl_pm.c | 2 +- arch/arm/mach-pxa/sharpsl_pm.h | 2 +- arch/arm/mach-pxa/spitz_pm.c | 9 +++------ 4 files changed, 9 insertions(+), 17 deletions(-) diff --git a/arch/arm/mach-pxa/corgi_pm.c b/arch/arm/mach-pxa/corgi_pm.c index d9206811be9b..c71c483f410e 100644 --- a/arch/arm/mach-pxa/corgi_pm.c +++ b/arch/arm/mach-pxa/corgi_pm.c @@ -131,16 +131,11 @@ static int corgi_should_wakeup(unsigned int resume_on_alarm) return is_resume; } -static unsigned long corgi_charger_wakeup(void) +static bool corgi_charger_wakeup(void) { - unsigned long ret; - - ret = (!gpio_get_value(CORGI_GPIO_AC_IN) << GPIO_bit(CORGI_GPIO_AC_IN)) - | (!gpio_get_value(CORGI_GPIO_KEY_INT) - << GPIO_bit(CORGI_GPIO_KEY_INT)) - | (!gpio_get_value(CORGI_GPIO_WAKEUP) - << GPIO_bit(CORGI_GPIO_WAKEUP)); - return ret; + return !gpio_get_value(CORGI_GPIO_AC_IN) || + !gpio_get_value(CORGI_GPIO_KEY_INT) || + !gpio_get_value(CORGI_GPIO_WAKEUP); } unsigned long corgipm_read_devdata(int type) diff --git a/arch/arm/mach-pxa/sharpsl_pm.c b/arch/arm/mach-pxa/sharpsl_pm.c index b80eab9993c5..249b7bd5fbc4 100644 --- a/arch/arm/mach-pxa/sharpsl_pm.c +++ b/arch/arm/mach-pxa/sharpsl_pm.c @@ -744,7 +744,7 @@ static int sharpsl_off_charge_battery(void) time = RCNR; while (1) { /* Check if any wakeup event had occurred */ - if (sharpsl_pm.machinfo->charger_wakeup() != 0) + if (sharpsl_pm.machinfo->charger_wakeup()) return 0; /* Check for timeout */ if ((RCNR - time) > SHARPSL_WAIT_CO_TIME) diff --git a/arch/arm/mach-pxa/sharpsl_pm.h b/arch/arm/mach-pxa/sharpsl_pm.h index 905be6755f04..fa75b6df8134 100644 --- a/arch/arm/mach-pxa/sharpsl_pm.h +++ b/arch/arm/mach-pxa/sharpsl_pm.h @@ -34,7 +34,7 @@ struct sharpsl_charger_machinfo { #define SHARPSL_STATUS_LOCK 5 #define SHARPSL_STATUS_CHRGFULL 6 #define SHARPSL_STATUS_FATAL 7 - unsigned long (*charger_wakeup)(void); + bool (*charger_wakeup)(void); int (*should_wakeup)(unsigned int resume_on_alarm); void (*backlight_limit)(int); int (*backlight_get_status) (void); diff --git a/arch/arm/mach-pxa/spitz_pm.c b/arch/arm/mach-pxa/spitz_pm.c index ea9f9034cb54..4e64a140252e 100644 --- a/arch/arm/mach-pxa/spitz_pm.c +++ b/arch/arm/mach-pxa/spitz_pm.c @@ -165,13 +165,10 @@ static int spitz_should_wakeup(unsigned int resume_on_alarm) return is_resume; } -static unsigned long spitz_charger_wakeup(void) +static bool spitz_charger_wakeup(void) { - unsigned long ret; - ret = ((!gpio_get_value(SPITZ_GPIO_KEY_INT) - << GPIO_bit(SPITZ_GPIO_KEY_INT)) - | gpio_get_value(SPITZ_GPIO_SYNC)); - return ret; + return !gpio_get_value(SPITZ_GPIO_KEY_INT) || + gpio_get_value(SPITZ_GPIO_SYNC); } unsigned long spitzpm_read_devdata(int type)