From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Warren Subject: Re: [PATCH] arm: mach-tegra: check wether we have debugfs enabled or not Date: Wed, 17 Oct 2012 15:22:13 -0600 Message-ID: <507F2185.3070408@wwwdotorg.org> References: <1350501196-5632-1-git-send-email-devendra.aaru@gmail.com> <20121017201244.GN21164@n2100.arm.linux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20121017201244.GN21164-l+eeeJia6m9vn6HldHNs0ANdhmdF6hFW@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Russell King - ARM Linux Cc: Devendra Naga , linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-tegra@vger.kernel.org On 10/17/2012 02:12 PM, Russell King - ARM Linux wrote: > On Wed, Oct 17, 2012 at 03:13:16PM -0400, Devendra Naga wrote: >> if debugfs is not enabled in kernel it returns -ENODEV, check it >> with IS_ERR_OR_NULL along with the null return if it fails to >> create a file in debugfs. >> >> Signed-off-by: Devendra Naga >> --- >> arch/arm/mach-tegra/powergate.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/arch/arm/mach-tegra/powergate.c b/arch/arm/mach-tegra/powergate.c >> index de0662d..1809b91d 100644 >> --- a/arch/arm/mach-tegra/powergate.c >> +++ b/arch/arm/mach-tegra/powergate.c >> @@ -269,7 +269,7 @@ int __init tegra_powergate_debugfs_init(void) >> if (powergate_name) { >> d = debugfs_create_file("powergate", S_IRUGO, NULL, NULL, >> &powergate_fops); >> - if (!d) >> + if (IS_ERR_OR_NULL(d)) >> return -ENOMEM; > > So, you want to make this function hard-fail if a debugfs error occurs > _or_ debugfs is not configured? That doesn't seem to be a clever thing > to do. In practice, that quoted chunk of code is inside an #ifdef CONFIG_DEBUG_FS, so according to the documentation for debugfs_create_file(), the IS_ERR case of IS_ERR_OR_NULL cannot happen here. So, the above change is a no-op, so there's not much point applying it.