Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759074Ab3DYUH6 (ORCPT ); Thu, 25 Apr 2013 16:07:58 -0400 Received: from mail-vc0-f180.google.com ([209.85.220.180]:40650 "EHLO mail-vc0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754080Ab3DYUH5 (ORCPT ); Thu, 25 Apr 2013 16:07:57 -0400 MIME-Version: 1.0 In-Reply-To: <1366910944-3033663-16-git-send-email-arnd@arndb.de> References: <1366910944-3033663-1-git-send-email-arnd@arndb.de> <1366910944-3033663-16-git-send-email-arnd@arndb.de> Date: Thu, 25 Apr 2013 16:07:56 -0400 Message-ID: Subject: Re: [PATCH 15/21] thermal: cooling: avoid uninitialied used gcc warning From: "edubezval@gmail.com" To: Arnd Bergmann Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Zhang Rui , Amit Daniel kachhap , "Valentin, Eduardo" Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3110 Lines: 81 Arnd, On Thu, Apr 25, 2013 at 1:28 PM, Arnd Bergmann wrote: > The newly rewritten get_property() function causes a bogus warning > from gcc-3.8, which cannot figure out that "level" is always > initialized at the point where it gets evaluated: > > drivers/thermal/cpu_cooling.c: In function 'get_property': > drivers/thermal/cpu_cooling.c:189:37: warning: 'level' may be used uninitialized in this function [-Wmaybe-uninitialized] > if (property == GET_FREQ && level == j) { > ^ > > Slightly rearranging the code makes this more obvious and > avoids the warning. > > Signed-off-by: Arnd Bergmann > Cc: Zhang Rui > Cc: Amit Daniel kachhap Rui has merged a patch that removes this bogus compiler warning: http://git.kernel.org/cgit/linux/kernel/git/rzhang/linux.git/commit/?h=next&id=4469b99743d296e24aefc5f8ed7df1bc9cfbbac8 Though, as not as elegant as your patch, it does the trick. :-) > --- > drivers/thermal/cpu_cooling.c | 17 +++++++++-------- > 1 file changed, 9 insertions(+), 8 deletions(-) > > diff --git a/drivers/thermal/cpu_cooling.c b/drivers/thermal/cpu_cooling.c > index 768b508..34878e6 100644 > --- a/drivers/thermal/cpu_cooling.c > +++ b/drivers/thermal/cpu_cooling.c > @@ -165,10 +165,6 @@ static int get_property(unsigned int cpu, unsigned long input, > return 0; > } > > - if (property == GET_FREQ) > - level = descend ? input : (max_level - input -1); > - > - > for (i = 0, j = 0; table[i].frequency != CPUFREQ_TABLE_END; i++) { > /* ignore invalid entry */ > if (table[i].frequency == CPUFREQ_ENTRY_INVALID) > @@ -186,10 +182,15 @@ static int get_property(unsigned int cpu, unsigned long input, > *output = descend ? j : (max_level - j - 1); > return 0; > } > - if (property == GET_FREQ && level == j) { > - /* get frequency by level */ > - *output = freq; > - return 0; > + > + if (property == GET_FREQ) { > + level = descend ? input : (max_level - input -1); > + > + if (level == j) { > + /* get frequency by level */ > + *output = freq; > + return 0; > + } > } > j++; > } > -- > 1.8.1.2 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/ -- Eduardo Bezerra Valentin -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/