From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754488AbZHPRvi (ORCPT ); Sun, 16 Aug 2009 13:51:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753335AbZHPRvi (ORCPT ); Sun, 16 Aug 2009 13:51:38 -0400 Received: from bu3sch.de ([62.75.166.246]:50424 "EHLO vs166246.vserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753218AbZHPRvh (ORCPT ); Sun, 16 Aug 2009 13:51:37 -0400 From: Michael Buesch To: Thomas Gleixner Subject: Re: Threaded interrupt handlers broken? Date: Sun, 16 Aug 2009 19:51:13 +0200 User-Agent: KMail/1.9.9 Cc: linux-kernel@vger.kernel.org References: <200908161153.14081.mb@bu3sch.de> <200908161546.46328.mb@bu3sch.de> In-Reply-To: X-Move-Along: Nothing to see here. No, really... Nothing. MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200908161951.13988.mb@bu3sch.de> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sunday 16 August 2009 16:25:13 Thomas Gleixner wrote: > On Sun, 16 Aug 2009, Michael Buesch wrote: > > On Sunday 16 August 2009 15:22:29 Thomas Gleixner wrote: > > > > > > + if (0&&unlikely(desc->status & IRQ_DISABLED)) { > > > > > > So the interrupt is marked disabled. How do you setup the handler > > > ? And what does the primary handler do ? Can you post your driver > > > code please? > > > > This patch converts the b43 driver to threaded interrupts: > > http://bu3sch.de/patches/wireless-testing/20090816-1535/patches/002-b43-threaded-irq-handler.patch > > On the first glance this looks not too bad. the unlocked access to the > irq status registers looks a bit scary, but that is not relevant for > the problem at hand. Yeah it does ;) > > It kind of works with this hack applied to kernel/irq/manage.c > > Hmm. Is the interrupt of the device shared ? It's registered as shared, but on my machine it is not shared with anything else. > If yes, what's the other > device on that interrupt line ? what puzzles me is the fact that the > IRQ_DISABLED flag is set. Is there anything unusual in dmesg ? Here's my current kernel log with the two patches applied: http://bu3sch.de/misc/dmesg > > > So you wake when the thread counter is != 0 after the decrement. > > > > > > #define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) > > > > Yeah, isn't that what we want to do? I read the test as "wake other threads, > > if there are other threads" or something like that. > > No, it's for synchronize_irq(). When there are threaded handlers in > progress, then sychronize_irq() waits on the waitqueue until they are > finished. So we wake the queue when the last threaded handler of this > irq line returns from thread_fn. Ok, I understand. -- Greetings, Michael.