From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261885AbTKCDz2 (ORCPT ); Sun, 2 Nov 2003 22:55:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261889AbTKCDz2 (ORCPT ); Sun, 2 Nov 2003 22:55:28 -0500 Received: from mtaw4.prodigy.net ([64.164.98.52]:28055 "EHLO mtaw4.prodigy.net") by vger.kernel.org with ESMTP id S261885AbTKCDz1 (ORCPT ); Sun, 2 Nov 2003 22:55:27 -0500 Message-ID: <3FA5CF9E.2060507@pacbell.net> Date: Sun, 02 Nov 2003 19:46:38 -0800 From: David Brownell User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.2.1) Gecko/20030225 X-Accept-Language: en-us, en, fr MIME-Version: 1.0 To: davidm@hpl.hp.com CC: 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? 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> In-Reply-To: <16289.29015.81760.774530@napali.hpl.hp.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > 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? Most of that story is just submitting and completing URBs. I'd either try changing the spots in drivers/usb/core/hcd.c marked as appropriate for generic MONITOR_URB hooks (printk if it's your HID device, maybe), or manually turn on whatever HCD-specific hooks exist (maybe use a VERBOSE message level). Such a thing wasn't possible in 2.4 since there were too many different bizarre (and sometimes buggy) ways for URBs to return to the usb device drivers and get implicitly resubmitted. - Dave