From: Russell King - ARM Linux <linux@arm.linux.org.uk>
To: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Amit Daniel Kachhap <amit.daniel@samsung.com>,
Kukjin Kim <kgene.kim@samsung.com>,
linux-pm@vger.kernel.org, Viresh Kumar <viresh.kumar@linaro.org>,
linux-kernel@vger.kernel.org, cpufreq@vger.kernel.org,
"Rafael J. Wysocki" <rjw@sisk.pl>,
linux-samsung-soc@vger.kernel.org,
Thomas Abraham <thomas.abraham@linaro.org>,
Inderpal Singh <inderpal.singh@linaro.org>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH V3 1/4] cpufreq: exynos: Adding cpufreq driver for exynos5440
Date: Thu, 7 Mar 2013 15:37:36 +0000 [thread overview]
Message-ID: <20130307153736.GC4977@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <5138B200.7060906@samsung.com>
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 ?
WARNING: multiple messages have this Message-ID (diff)
From: linux@arm.linux.org.uk (Russell King - ARM Linux)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH V3 1/4] cpufreq: exynos: Adding cpufreq driver for exynos5440
Date: Thu, 7 Mar 2013 15:37:36 +0000 [thread overview]
Message-ID: <20130307153736.GC4977@n2100.arm.linux.org.uk> (raw)
In-Reply-To: <5138B200.7060906@samsung.com>
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 ?
next prev parent reply other threads:[~2013-03-07 15:37 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-07 4:13 [PATCH V3 1/4] cpufreq: exynos: Adding cpufreq driver for exynos5440 Amit Daniel Kachhap
2013-03-07 4:13 ` Amit Daniel Kachhap
2013-03-07 4:13 ` [PATCH V3 2/4] cpufreq: exynos: Remove error return even if no soc is found Amit Daniel Kachhap
2013-03-07 4:13 ` Amit Daniel Kachhap
2013-03-07 4:13 ` [PATCH V3 3/4] arm: exynos: Enable OPP library support for exynos5440 Amit Daniel Kachhap
2013-03-07 4:13 ` Amit Daniel Kachhap
2013-03-07 4:13 ` [PATCH V3 4/4] dts: Add cpufreq controller node for Exynos5440 SoC Amit Daniel Kachhap
2013-03-07 4:13 ` Amit Daniel Kachhap
2013-03-07 15:28 ` [PATCH V3 1/4] cpufreq: exynos: Adding cpufreq driver for exynos5440 Sylwester Nawrocki
2013-03-07 15:28 ` Sylwester Nawrocki
2013-03-07 15:37 ` Russell King - ARM Linux [this message]
2013-03-07 15:37 ` Russell King - ARM Linux
2013-03-11 3:44 ` amit kachhap
2013-03-11 3:44 ` amit kachhap
2013-03-11 3:43 ` amit kachhap
2013-03-11 3:43 ` amit kachhap
2013-03-09 10:47 ` Viresh Kumar
2013-03-09 10:47 ` Viresh Kumar
2013-03-11 3:45 ` amit kachhap
2013-03-11 3:45 ` amit kachhap
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