Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933629AbYBTVRw (ORCPT ); Wed, 20 Feb 2008 16:17:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1765583AbYBTVQT (ORCPT ); Wed, 20 Feb 2008 16:16:19 -0500 Received: from iolanthe.rowland.org ([192.131.102.54]:55414 "HELO iolanthe.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1764368AbYBTVQQ (ORCPT ); Wed, 20 Feb 2008 16:16:16 -0500 Date: Wed, 20 Feb 2008 16:16:15 -0500 (EST) From: Alan Stern X-X-Sender: stern@iolanthe.rowland.org To: David Brownell cc: Andre Tomt , Kernel development list , USB list Subject: Re: USB OOPS 2.6.25-rc2-git1 In-Reply-To: <47BC8E9D.8080309@tomt.net> Message-ID: 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 Content-Length: 1659 Lines: 40 On Wed, 20 Feb 2008, Andre Tomt wrote: > David Brownell wrote: > > On Tuesday 19 February 2008, Andre Tomt wrote: > >>> Can you try this diagnostic patch, to see if it reports any messages > >>> about IAA and/or IAAD oddities? There's surely a quick workaround > >>> for this, but I'd rather understand the root cause before patching. > >> Doesn't seem to have triggered anything. dmesg attached in case I missed > >> anything. > > > > You don't seem to have enabled CONFIG_USB_DEBUG, as the patch instructions > > say is needed to get such diagnostics ... I can tell because the startup > > messages from USB are pretty minimal. (See appended, vs what you sent...) > > > > Please try again with USB debugging enabled. > > Argh, silly me. Here you go (attached). It has not crashed yet with the > patch though. You know, Dave, seeing all those > ehci_hcd 0000:00:1d.7: IAA watchdog, lost IAA: status 8029 cmd 10021 lines in the log brings up some ideas that have been percolating in my mind for a while. They have to do with the possibility of a race between the watchdog routine and assertion of IAA. In fact, if the timing comes out just wrong then it's possible (on SMP systems) for an IAA interrupt to arrive when the watchdog routine has already started running. Then end_unlink_async() might get called right at the start of a new IAA cycle, or when the reclaim list is empty. Alan Stern -- 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/