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Date: Fri, 20 Apr 2007 16:29:31 +0100
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Jan Yenya Kasprzak <kas@fi.muni.cz>
Cc: Jiri Slaby <jirislaby@gmail.com>,
       Andrew Morton <akpm@linux-foundation.org>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/3] Char: mxser_new, fix recursive locking
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> Signed-off-by: Jan "Yenya" Kasprzak <kas@fi.muni.cz>
> Cc: Jiri Slaby <jirislaby@gmail.com>
> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>

Acked-by: Alan Cox <alan@redhat.com>
> 
> --- linux-2.6.21-rc2/drivers/char/mxser_new.c.orig	2007-04-20 15:41:46.000000000 +0200
> +++ linux-2.6.21-rc2/drivers/char/mxser_new.c	2007-04-20 15:46:46.000000000 +0200
> @@ -2230,7 +2230,14 @@
>  	port->mon_data.rxcnt += cnt;
>  	port->mon_data.up_rxcnt += cnt;
>  
> +	/*
> +	 * We are called from an interrupt context with &port->slock
> +	 * being held. Drop it temporarily in order to prevent
> +	 * recursive locking.
> +	 */
> +	spin_unlock(&port->slock);
>  	tty_flip_buffer_push(tty);
> +	spin_lock(&port->slock);
>  }
>