From mboxrd@z Thu Jan  1 00:00:00 1970
From: Thomas Gleixner <tglx@linutronix.de>
Subject: Re: Kernel panic with PREEMPT_RT_FULL and UIO driver
Date: Wed, 21 Dec 2011 12:38:45 +0100 (CET)
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To: Lukas Erlinghagen <lukas.erlinghagen@x2e.de>
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On Wed, 21 Dec 2011, Lukas Erlinghagen wrote:

> Dear list,
> 
> we're getting the kernel panic postet below on our system (Kernel version is
> 3.0.3-rt11, the platform is an embedded PowerPC 440 in a Virtex 5 FPGA, the
> device controlled by the UIO driver is a Freescale MFR4310 controller, and the
> interrupt is triggered by a high-active interrupt pin). This panic only occurs
> when using CONFIG_PREEMPT_RT_FULL, and only under high interrupt load on the
> MFR.
>
> I've also included our IRQ handler (registered with IRQF_ONESHOT) and IRQ
> control function.
> 
> Is there something fundamentally wrong we're doing, and if so, where can I

You are running the UIO interrupt handler with IRQF_NO_THREAD. That
can't work on RT.

Thanks,

	tglx