From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: Re: [PATCH] PM / OPP: avoid maybe-uninitialized warning Date: Fri, 16 Sep 2016 08:19:51 +0530 Message-ID: <20160916024950.GA6313@vireshk-i7> References: <20160915153917.3001855-1-arnd@arndb.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pf0-f176.google.com ([209.85.192.176]:34379 "EHLO mail-pf0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753916AbcIPCtz (ORCPT ); Thu, 15 Sep 2016 22:49:55 -0400 Received: by mail-pf0-f176.google.com with SMTP id p64so22666513pfb.1 for ; Thu, 15 Sep 2016 19:49:54 -0700 (PDT) Content-Disposition: inline In-Reply-To: <20160915153917.3001855-1-arnd@arndb.de> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Arnd Bergmann Cc: Viresh Kumar , Nishanth Menon , Stephen Boyd , "Rafael J. Wysocki" , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org On 15-09-16, 17:38, Arnd Bergmann wrote: > When CONFIG_OPTIMIZE_INLINING is set and we are building with -Wmaybe-uninitialized > enabled, we can get a warning for the opp core driver: > > drivers/base/power/opp/core.c: In function 'dev_pm_opp_set_rate': > drivers/base/power/opp/core.c:560:8: warning: 'ou_volt_min' may be used uninitialized in this function [-Wmaybe-uninitialized] > > This has only now appeared as a result of commit 797da5598f3a ("PM / devfreq: > Add COMPILE_TEST for build coverage"), which makes the driver visible in > some configurations that didn't have it before. > > The warning is a false positive that I got with gcc-6.1.1, but there is > a simple workaround in removing the local variables that we get warnings > for (all three are affected depending on the configuration). This also > makes the code easier to read. > > Signed-off-by: Arnd Bergmann > --- > drivers/base/power/opp/core.c | 10 +++------- > 1 file changed, 3 insertions(+), 7 deletions(-) > > diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c > index df0c70963d9e..4c7c6da7a989 100644 > --- a/drivers/base/power/opp/core.c > +++ b/drivers/base/power/opp/core.c > @@ -584,7 +584,6 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq) > struct clk *clk; > unsigned long freq, old_freq; > unsigned long u_volt, u_volt_min, u_volt_max; > - unsigned long ou_volt, ou_volt_min, ou_volt_max; > int ret; > > if (unlikely(!target_freq)) { > @@ -620,11 +619,7 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq) > } > > old_opp = _find_freq_ceil(opp_table, &old_freq); > - if (!IS_ERR(old_opp)) { > - ou_volt = old_opp->u_volt; > - ou_volt_min = old_opp->u_volt_min; > - ou_volt_max = old_opp->u_volt_max; > - } else { > + if (IS_ERR(old_opp)) { > dev_err(dev, "%s: failed to find current OPP for freq %lu (%ld)\n", > __func__, old_freq, PTR_ERR(old_opp)); > } > @@ -683,7 +678,8 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq) > restore_voltage: > /* This shouldn't harm even if the voltages weren't updated earlier */ > if (!IS_ERR(old_opp)) > - _set_opp_voltage(dev, reg, ou_volt, ou_volt_min, ou_volt_max); > + _set_opp_voltage(dev, reg, old_opp->u_volt, > + old_opp->u_volt_min, old_opp->u_volt_max); > > return ret; > } Acked-by: Viresh Kumar -- viresh