From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261778AbUK0Gr3 (ORCPT ); Sat, 27 Nov 2004 01:47:29 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261784AbUK0Gr2 (ORCPT ); Sat, 27 Nov 2004 01:47:28 -0500 Received: from ylpvm15-ext.prodigy.net ([207.115.57.46]:18910 "EHLO ylpvm15.prodigy.net") by vger.kernel.org with ESMTP id S261788AbUKZTLD (ORCPT ); Fri, 26 Nov 2004 14:11:03 -0500 From: David Brownell To: linux-usb-devel@lists.sourceforge.net Subject: Re: [linux-usb-devel] [PATCH] Ohci-hcd: fix endless loop Date: Fri, 26 Nov 2004 09:21:26 -0800 User-Agent: KMail/1.7.1 Cc: Colin Leroy , linux-kernel@vger.kernel.org, Benjamin Herrenschmidt , Greg KH References: <20041125191726.5ca95299@jack.colino.net> <200411260838.10508.david-b@pacbell.net> <20041126175454.17b62cf5@pirandello> In-Reply-To: <20041126175454.17b62cf5@pirandello> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200411260921.26628.david-b@pacbell.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Friday 26 November 2004 08:54, Colin Leroy wrote: > On 26 Nov 2004 at 08h11, David Brownell wrote: > > Hi, > > > The infinite loop means that something trashed the stack, yes? > > > > The "limit-- < -1000" test below should never be able to succeed > > unless the previous "limit-- == 0" test got trashed by having > > something obliterate the stack. > > Sure? the (limit -- == 0) gotoes higher to test again. > from what I understand the loop goes back to rescan 1000 times, then once > to sanitize, then to back to rescan again infinetely... > I may be wrong but I don't think there's a stack corruption there. The "limit" isn't tested a 1001st time, since the ED state changed. For that matter, any time that the IRQ lossage appears, there's always been something that damaged the IRQ setup. - Dave