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	Thu, 26 Jul 2007 19:41:38 +1000 (EST)
Subject: RE: [PATCH] mpx5200_uart: drop port lock across tty_flip_buffer() call
From: Thomas Gleixner <tglx@linutronix.de>
To: Daniel Schnell <daniel.schnell@marel.com>
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Date: Thu, 26 Jul 2007 11:41:18 +0200
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On Thu, 2007-07-26 at 09:25 +0000, Daniel Schnell wrote:
> Thomas Gleixner wrote:
> 
> > On Wed, 2007-07-25 at 13:42 -0600, Grant Likely wrote:
> >> On 7/25/07, Thomas Gleixner <tglx@linutronix.de> wrote:
> >>> The port lock needs to be dropped across the tty_flip_buffer call,
> >>> as it would lead to a deadlock with the spin_lock(&port->lock) in
> >>> uart_start() 
> >>> 
> >>> Uncovered by lockdep / preempt-rt
> >>> 
> >>> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
> 
> While you are at it 8°> ... the mpc5200-fec driver has serious
> problems with preempt-rt, similar to what the IBM emac had ....

Care to whip up a patch ?

	tglx