From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux Subject: Re: [PATCH V3 1/4] cpufreq: exynos: Adding cpufreq driver for exynos5440 Date: Thu, 7 Mar 2013 15:37:36 +0000 Message-ID: <20130307153736.GC4977@n2100.arm.linux.org.uk> References: <1362629627-10012-1-git-send-email-amit.daniel@samsung.com> <5138B200.7060906@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from caramon.arm.linux.org.uk ([78.32.30.218]:57163 "EHLO caramon.arm.linux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753478Ab3CGPhq (ORCPT ); Thu, 7 Mar 2013 10:37:46 -0500 Content-Disposition: inline In-Reply-To: <5138B200.7060906@samsung.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Sylwester Nawrocki Cc: Amit Daniel Kachhap , Kukjin Kim , linux-pm@vger.kernel.org, Viresh Kumar , linux-kernel@vger.kernel.org, cpufreq@vger.kernel.org, "Rafael J. Wysocki" , linux-samsung-soc@vger.kernel.org, Thomas Abraham , Inderpal Singh , linux-arm-kernel@lists.infradead.org On Thu, Mar 07, 2013 at 04:28:00PM +0100, Sylwester Nawrocki wrote: > On 03/07/2013 05:13 AM, Amit Daniel Kachhap wrote: > > + dvfs_info->cpu_clk = devm_clk_get(dvfs_info->dev, "armclk"); > > + if (IS_ERR_OR_NULL(dvfs_info->cpu_clk)) { > > devm_clk_get() return value needs to be checked with IS_ERR(), > not IS_ERR_OR_NULL(). > > > + pr_err("Failed to get cpu clock\n"); > > + ret = PTR_ERR(dvfs_info->cpu_clk); > > + goto err_free_table; Amit, to illustrate why this is wrong, consider this: 1. Set cpu_clk to NULL. 2. Realise IS_ERR_OR_NULL(NULL) is true. 3. What is the value of PTR_ERR(NULL) ? 4. What effect does that have when you jump to err_free_table ? 5. What value is returned from this function in that case ? 6. What does that return value mean to the driver core ?