From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262796AbTKCV0F (ORCPT ); Mon, 3 Nov 2003 16:26:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263270AbTKCV0F (ORCPT ); Mon, 3 Nov 2003 16:26:05 -0500 Received: from palrel11.hp.com ([156.153.255.246]:37013 "EHLO palrel11.hp.com") by vger.kernel.org with ESMTP id S262796AbTKCV0C (ORCPT ); Mon, 3 Nov 2003 16:26:02 -0500 From: David Mosberger MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16294.51171.463585.783228@napali.hpl.hp.com> Date: Mon, 3 Nov 2003 13:25:55 -0800 To: David Brownell Cc: davidm@hpl.hp.com, Greg KH , vojtech@suse.cz, linux-usb-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: [linux-usb-devel] Re: serious 2.6 bug in USB subsystem? In-Reply-To: <3FA5CF9E.2060507@pacbell.net> References: <200310272235.h9RMZ9x1000602@napali.hpl.hp.com> <20031028013013.GA3991@kroah.com> <200310280300.h9S30Hkw003073@napali.hpl.hp.com> <3FA12A2E.4090308@pacbell.net> <16289.29015.81760.774530@napali.hpl.hp.com> <3FA5CF9E.2060507@pacbell.net> X-Mailer: VM 7.07 under Emacs 21.2.1 Reply-To: davidm@hpl.hp.com X-URL: http://www.hpl.hp.com/personal/David_Mosberger/ Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org >>>>> On Sun, 02 Nov 2003 19:46:38 -0800, David Brownell said: David> I'm not sure that if the HID driver were to pass a null David> buffer pointer, it would be caught anywhere. >> OK, I'll try to find some time to trace the I/O MMU calls to see >> if something isn't kosher at that level. Is there a good way of >> getting a relatively high-level of tracing in the USB subsystem >> that would some me what's going on between the HID and the core >> USB level? Dave.B> Most of that story is just submitting and completing URBs. Yeah. And it appears that it's the very first call to hid_submit_ctrl() that's triggering the problem (not always, but about 9 out of 10 times). I dumped some of the key fields for the URB being submitted and they all looked saned to me. Dave.B> I'd either try changing the spots in drivers/usb/core/hcd.c Dave.B> marked as appropriate for generic MONITOR_URB hooks (printk Dave.B> if it's your HID device, maybe), or manually turn on Dave.B> whatever HCD-specific hooks exist (maybe use a VERBOSE Dave.B> message level). OK, thanks for the suggestion. I'll keep looking, but will be on travel this week, so I may not be able to spend much time on this problem. --david