Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760482AbXK1UxR (ORCPT ); Wed, 28 Nov 2007 15:53:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755183AbXK1Uw6 (ORCPT ); Wed, 28 Nov 2007 15:52:58 -0500 Received: from gateway-1237.mvista.com ([63.81.120.158]:10639 "EHLO gateway-1237.mvista.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757202AbXK1Uw5 (ORCPT ); Wed, 28 Nov 2007 15:52:57 -0500 Subject: Re: [PATCH PREEMPT_RT]: On AT91 ARM: GPIO Interrupt handling can/will stall forever From: Daniel Walker To: Steven Rostedt Cc: Russell King - ARM Linux , Remy Bohmer , RT , linux-kernel , ARM Linux Mailing List , Thomas Gleixner , Ingo Molnar In-Reply-To: References: <3efb10970711260531x5e9f05acgfabdfa885a220192@mail.gmail.com> <3efb10970711260545i419a8352o4ca5248b10d81db5@mail.gmail.com> <1196176294.13982.58.camel@localhost.localdomain> <1196177122.23808.7.camel@imap.mvista.com> <1196178834.23808.11.camel@imap.mvista.com> <3efb10970711280638l3f57104y8cf9f2e58235c3@mail.gmail.com> <20071128172509.GA30173@flint.arm.linux.org.uk> <20071128200550.GA3494@flint.arm.linux.org.uk> Content-Type: text/plain Date: Wed, 28 Nov 2007 12:44:31 -0800 Message-Id: <1196282672.27964.32.camel@imap.mvista.com> Mime-Version: 1.0 X-Mailer: Evolution 2.10.3 (2.10.3-4.fc7) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 956 Lines: 25 On Wed, 2007-11-28 at 15:16 -0500, Steven Rostedt wrote: > > This could also simply be unique to the interrupt threads (only in RT). So > perhaps the patch is OK. > > Remy, sorry about this round-a-bout. But I don't have any of the hardware > that this affects, and I'm just being cautious. Ignoring the ARM side of things for a sec, handle_simple_irq() will mask() the interrupt in the special case that an interrupt is already in the processes of being handled.. handle_simple_irq() also unmasks when it finishes handling an interrupt (something real time adds for some reason) .. In terms of threading the irq everything is the same except there is no unmask() call when the thread finishes .. Daniel - 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/