From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755790AbZHPV2l (ORCPT ); Sun, 16 Aug 2009 17:28:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751710AbZHPV2l (ORCPT ); Sun, 16 Aug 2009 17:28:41 -0400 Received: from www.tglx.de ([62.245.132.106]:52195 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751292AbZHPV2k (ORCPT ); Sun, 16 Aug 2009 17:28:40 -0400 Date: Sun, 16 Aug 2009 23:28:37 +0200 (CEST) From: Thomas Gleixner To: Michael Buesch cc: linux-kernel@vger.kernel.org Subject: Re: Threaded interrupt handlers broken? In-Reply-To: <200908162301.21775.mb@bu3sch.de> Message-ID: References: <200908161153.14081.mb@bu3sch.de> <200908161951.13988.mb@bu3sch.de> <200908162301.21775.mb@bu3sch.de> 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 On Sun, 16 Aug 2009, Michael Buesch wrote: > On Sunday 16 August 2009 22:05:59 Thomas Gleixner wrote: > > Hmm. Nothing interesting AFAICT, but it would be really interesting to > > find out why the IRQ_DISABLED flag is set. > > > > Can you add some debug into disable_irq() e.g. WARN_ON(irq == > > BC43_IRQ_NR); so we can see what disables that interrupt. > > I do not see a warning, if I put this into __disable_irq(): > WARN_ON(irq == 52); > /proc/interrupts shows 52 as IRQ number for b43. > And dmesg shows "... irq 52 on host ... mapped to virtual irq 52". > So I guess the test is OK and the flag is added by some other means. > Maybe by some weird powerpc architecture code? > > It seems a little bit weird, however, that the WARN_ON does not even trigger > on module unload, which as far as I can tell should disable the IRQ line > in the free_irq() call (no other shared devices on this IRQ). free_irq does not call disable_irq(). There are only a few places which set that flag. dynamic_irq_init() which should not be called in your system __set_irq_handler() only if a handler gets uninstalled and replaced by handle_bad_irq __disable_irq() which you already excluded __freq_irq() which should not be called note_interrupt() which should be visible in dmesg, but we do not see such a thing. IRQ_DISABLED is cleared at even less places: request_irq() and __enable_irq() I'm really confused. Can you please add debug into those places and provide the output. Also please print desc->status of irq 52 before and after calling request_threaded_irq(). Thanks, tglx