From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Gleixner <tglx@linutronix.de>
Subject: Re: [PATCH] rtc-tegra: properly initialize spinlock
Date: Sat, 23 Jul 2011 09:29:08 +0200 (CEST)
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Cc: Andrew Morton <akpm@linux-foundation.org>,
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	<u.kleine-koenig@pengutronix.de>, Andrew Chew <achew@nvidia.com>,
	linux-rt-users@vger.kernel.org,
	Alessandro Zummo <a.zummo@towertech.it>,
	linux-kernel@vger.kernel.org, jkastner@redhat.com
To: Sven-Thorsten Dietrich <thebigcorporation@gmail.com>
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On Fri, 22 Jul 2011, Sven-Thorsten Dietrich wrote:
> 
> On Jul 22, 2011, at 3:13 PM, Andrew Morton wrote:
> 
> > On Fri, 22 Jul 2011 10:35:56 +0200
> > Uwe Kleine-K__nig <u.kleine-koenig@pengutronix.de> wrote:
> > 
> >> Using __SPIN_LOCK_UNLOCKED for a dynamically allocated lock is wrong and
> >> breaks with PREEMPT_RT_FULL.
> > 
> > Please define "breaks".  Lockdep warnings?  Deadlocks?
> 
> Narrr, I think its a compile-time problem with the static initializer.

Correct. The macro expansion magic of the static initializer barfs and
with lockdep the lockdep key assignment is missing.

Thanks,

	tglx