Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753946AbZI3M60 (ORCPT ); Wed, 30 Sep 2009 08:58:26 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753046AbZI3M6Z (ORCPT ); Wed, 30 Sep 2009 08:58:25 -0400 Received: from www.tglx.de ([62.245.132.106]:54399 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752764AbZI3M6Z (ORCPT ); Wed, 30 Sep 2009 08:58:25 -0400 Date: Wed, 30 Sep 2009 14:57:25 +0200 (CEST) From: Thomas Gleixner To: Remy Bohmer cc: linux-rt-users , LKML Subject: Re: 2.6.31-rt11 freeze on userland start on ARM In-Reply-To: <3efb10970909211136g4e74c8b3vc339d548cdd0959f@mail.gmail.com> Message-ID: References: <3efb10970909211136g4e74c8b3vc339d548cdd0959f@mail.gmail.com> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1400 Lines: 39 On Mon, 21 Sep 2009, Remy Bohmer wrote: > So, as workaround/test I made this change: > > Index: linux-2.6.31/drivers/serial/atmel_serial.c > =================================================================== > --- linux-2.6.31.orig/drivers/serial/atmel_serial.c 2009-09-21 > 19:44:48.000000000 +0200 > +++ linux-2.6.31/drivers/serial/atmel_serial.c 2009-09-21 > 19:45:15.000000000 +0200 > @@ -808,7 +808,8 @@ static int atmel_startup(struct uart_por > /* > * Allocate the IRQ > */ > - retval = request_irq(port->irq, atmel_interrupt, IRQF_SHARED, > + retval = request_irq(port->irq, atmel_interrupt, > + IRQF_SHARED | IRQF_NODELAY, > tty ? tty->name : "atmel_serial", port); > if (retval) { > printk("atmel_serial: atmel_startup - Can't get irq\n"); The serial irq cannot run in hard irq context. There are two solutions to this problem: 1) Use the other timer which is available on AT91. 2) Make the serial driver explicitely threaded and check in the hardirq handler whether the irq originated from the serial driver. If yes, disable it in the serial device and return IRQ_WAKE_THREAD otherwise return IRQ_NONE. Thanks, tglx -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/