Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932116AbXK1VTU (ORCPT ); Wed, 28 Nov 2007 16:19:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761544AbXK1VSA (ORCPT ); Wed, 28 Nov 2007 16:18:00 -0500 Received: from ms-smtp-04.nyroc.rr.com ([24.24.2.58]:56254 "EHLO ms-smtp-04.nyroc.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758947AbXK1VR6 (ORCPT ); Wed, 28 Nov 2007 16:17:58 -0500 Date: Wed, 28 Nov 2007 16:13:07 -0500 (EST) From: Steven Rostedt X-X-Sender: rostedt@gandalf.stny.rr.com To: Daniel Walker cc: Russell King - ARM Linux , Remy Bohmer , RT , linux-kernel , ARM Linux Mailing List , Thomas Gleixner , Ingo Molnar Subject: Re: [PATCH PREEMPT_RT]: On AT91 ARM: GPIO Interrupt handling can/will stall forever In-Reply-To: <1196282672.27964.32.camel@imap.mvista.com> Message-ID: 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> <1196282672.27964.32.camel@imap.mvista.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1209 Lines: 32 On Wed, 28 Nov 2007, Daniel Walker wrote: > > 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 .. > OK, to be honest, I never fully understood the concept of this "simple_irq". I figured it was because of the ARM architecture. Your arguments seem reasonable and you are probably correct. But I didn't write this code, nor do I understand it, and before I go ahead and change it, I'll wait to hear input from Thomas. Hopefully, he'll be back soon. Perhaps my confusion about the simple_irq part is from the bug you are trying to fix. I've been confused by why it was different ;-) -- Steve - 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/