From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752679AbaIGUng (ORCPT ); Sun, 7 Sep 2014 16:43:36 -0400 Received: from mout.kundenserver.de ([212.227.17.13]:61599 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751911AbaIGUne (ORCPT ); Sun, 7 Sep 2014 16:43:34 -0400 From: Arnd Bergmann To: Alessandro Zummo Cc: rtc-linux@googlegroups.com, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Subject: [PATCH] rtc: pcf8563: fix uninitialized use warning Date: Sun, 07 Sep 2014 22:42:43 +0200 Message-ID: <3640058.m4Rfp1dmTJ@wuerfel> User-Agent: KMail/4.11.5 (Linux/3.16.0-10-generic; KDE/4.11.5; x86_64; ; ) MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V02:K0:vyIvX/pu5ooSPjgADPg8g+ryeGD9DlqJkLTz1fKjGPP ZTv5erWPLGlhbFXL+qnXJCLkn5bmvqeUOTu+MTjIbZqIJiaW0e LZXMnDNKGA3lVilkybmVsGnaQOW8cmhbfWrFT6f841yFtws3nQ E6kc84paCOqgFhsYMnuDMeo5OqGrEpaXLVVCXG2PIgzchINqZe bVIQUb4DaN+USRXbLSbAZIH5KUF3IOXEe9kAV6ENlIyoal+Enq Uc1HsOmCFF0obgMXjOlKpxA6MRuoQjwc//KHXVNUzQnHhFapSi Gxm4o8WfH3F21H3Ut0XPwnWCCW4Bhjo/RsFwdEIBGf8z+w5H82 kq//uQx4cOvQQ7VbJZQY= X-UI-Out-Filterresults: notjunk:1; Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org gcc-4.9 found a potential condition under which the 'pending' variable may be used uninitialized: drivers/rtc/rtc-pcf8563.c: In function 'pcf8563_irq': drivers/rtc/rtc-pcf8563.c:173:5: warning: 'pending' may be used uninitialized in this function [-Wmaybe-uninitialized] This is because in the pcf8563_get_alarm_mode() function, we check any nonzero return of pcf8563_read_block_data, but in the irq function we only check for negative values, so a possible positive value does not get detected if the compiler chooses not to inline the entire call chain. Checking for any non-zero value in the interrupt handler as well is just as correct and lets the compiler know what we are doing, without needing a bogus initialization. Signed-off-by: Arnd Bergmann diff --git a/drivers/rtc/rtc-pcf8563.c b/drivers/rtc/rtc-pcf8563.c index 5a197d9dc7e7..3a6f994c4da8 100644 --- a/drivers/rtc/rtc-pcf8563.c +++ b/drivers/rtc/rtc-pcf8563.c @@ -167,7 +167,7 @@ static irqreturn_t pcf8563_irq(int irq, void *dev_id) char pending; err = pcf8563_get_alarm_mode(pcf8563->client, NULL, &pending); - if (err < 0) + if (err) return err; if (pending) {