From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752792AbcBOUih (ORCPT ); Mon, 15 Feb 2016 15:38:37 -0500 Received: from mout.kundenserver.de ([212.227.126.131]:58243 "EHLO mout.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752759AbcBOUie (ORCPT ); Mon, 15 Feb 2016 15:38:34 -0500 From: Arnd Bergmann To: linaro-kernel@lists.linaro.org Cc: Viresh Kumar , Rafael Wysocki , Viresh Kumar , Nishanth Menon , Stephen Boyd , Jon Hunter , linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org Subject: Re: [PATCH] PM / OPP: Initialize regulator pointer to an error value Date: Mon, 15 Feb 2016 21:38:14 +0100 Message-ID: <17646703.2nZXD4icYj@wuerfel> User-Agent: KMail/4.11.5 (Linux/3.16.0-10-generic; KDE/4.11.5; x86_64; ; ) In-Reply-To: <743509d913cbc0e725bea52281be03b009e02bb5.1455553501.git.viresh.kumar@linaro.org> References: <1455544758-7718-1-git-send-email-jonathanh@nvidia.com> <743509d913cbc0e725bea52281be03b009e02bb5.1455553501.git.viresh.kumar@linaro.org> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" X-Provags-ID: V03:K0:eaceA/ZG68LDkQP2s2PWzdKdS2GVQN8NDR2DBaNSIFGRG7Re0by Yn9dl/kauaVyAedySlH2ruc6UO2vxS1Z2nIgO8YA7mDRlBxeXJtfGkAd0S3ABe7lfskbx02 9y+N3pcC9YPRy2OPX5I55oAzyY5kd29Pw+Do1mD4gR3RC7gt1LDh4V7Bds6s6KjKj2XVJUK 0lD8T075ePih0qm0YKNhQ== X-UI-Out-Filterresults: notjunk:1;V01:K0:ai8IBE59E6c=:87z//+zzFGInWSYO1MF6jH r52IPEFGzxEE3DFYWUMZ2584T3IFv3odbOZKVQ1CU1AZ6SSVVlVLJ2cj90KoAFfR9RVOg4AnS 8a0V0fNQGz32gs+yI88US0Obh5JDR9gP+1xocsIudXoH4hPdu1ScXH/+0eml2KgC3wmH67LCZ vPGd3cW1IkUxNs+fyDf+1hQiPoT3r7bAx9mpMXFP1a3MtA7yOM7sw5nvQ+w29aYQop8zrQUgj ZwrpdY2DQmf+a6ADoeRW3HrTASJiDYTTzH4sRn04maHebWI6gRgd3DHZL+Q1MxOgzjVqUJIGY 6yN0CQq8nMGj1kjt1gthAl1i4x2oKdeFlAnXHNzhPWrgRaIAt4PgyKKBbIeN41o6hE0psPLhY 4H3UwO3704F6POmi+2nWtiGgNLMRm0hpX9T875lHOSbFlK8OqEjgG0HZJf4KraBS5oLLN+eqZ 2xbVT12gyMN5nd0lGTfrQEYzfUO92drH+rXT/Bz2SvE8BpLI48roDUreNKRKUnPlqiPxq09If W2IWrJ3VQWwfxCirdLRZ+greTF/gXykVyl25epoCAZXodJBbUIKotr9wIR+q3EbmcXg02YzPm kCi2NzefAXiofYNAI77b152sCe/GZEmTvFEuVUSWxdtw88xmTzWNRJlUBhPBtLj1pkTMJuTKT jdSEXdyCjtzYd5by4lWhF+7p6qJQLab2TCM68S0MQqdui+t6YGXChsDLWpGGqJl4hUqW7uWB5 dqzWMw53Yi/2GG4D Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Monday 15 February 2016 21:56:42 Viresh Kumar wrote: > We are currently required to do two checks for regulator pointer: > IS_ERR() and IS_NULL(). > > And multiple instances are reported, about both of these not being used > consistently and so resulting in crashes. > > Fix that by initializing regulator pointer with an error value and > checking it only against an error. > > This makes code consistent and efficient. There is usually something else wrong if you have to check for both. Why exactly do you need to check for both IS_ERR and NULL? > diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c > index d7cd4e265766..146b6197d598 100644 > --- a/drivers/base/power/opp/core.c > +++ b/drivers/base/power/opp/core.c > @@ -257,7 +257,7 @@ unsigned long dev_pm_opp_get_max_volt_latency(struct device *dev) > } > > reg = dev_opp->regulator; > - if (IS_ERR_OR_NULL(reg)) { > + if (IS_ERR(reg)) { > /* Regulator may not be required for device */ > if (reg) > dev_err(dev, "%s: Invalid regulator (%ld)\n", __func__, > @@ -798,6 +798,9 @@ static struct device_opp *_add_device_opp(struct device *dev) > of_node_put(np); > } > > + /* Set regulator to a non-NULL error value */ > + dev_opp->regulator = ERR_PTR(-EFAULT); > + > /* Find clk for the device */ > dev_opp->clk = clk_get(dev, NULL); > if (IS_ERR(dev_opp->clk)) { -EFAULT has a very specific meaning (accessing an invalid pointer from user space), I don't think you want that one. Arnd