From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 14 Aug 2001 14:30:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 14 Aug 2001 14:29:53 -0400 Received: from lips.borg.umn.edu ([160.94.232.50]:53253 "EHLO lips.borg.umn.edu") by vger.kernel.org with ESMTP id ; Tue, 14 Aug 2001 14:29:50 -0400 Message-ID: <3B794B4F.1000303@thebarn.com> Date: Tue, 14 Aug 2001 11:01:19 -0500 From: Russell Cattelan User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:0.9.3) Gecko/20010802 X-Accept-Language: en-us MIME-Version: 1.0 To: Andre Pang CC: Alan Cox , linux-kernel@vger.kernel.org Subject: Re: usb-uhci + SMP -> bad In-Reply-To: <20010814002131.A26321@bubba.toscano.org> <997794181.326309.1471.nullmailer@bozar.algorithm.com.au> 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 Andre Pang wrote: >On Tue, Aug 14, 2001 at 01:48:06PM +0100, Alan Cox wrote: > >>> - use the uhci USB driver when I'm using a USB printer. If I >>> use the usb-uhci driver with my USB printer, the whole system >>> locks. This has been reported a few times on LKML, >>> linux-usb-users, and linux-usb-developers and nobody helped, >>> but a few people wrote back with "me too"s. It was broken in >>> the trasnition from 2.4.3 to 2.4.4 and only seems to affect >>> SMP systems. I just gave up on USB printing and went back to >>> my parallel port. >>> >>usb-uhci seems to not be SMP safe. Ultimately we don't need both uhci >>drivers so that hasnt been one that worried me. Probably we should drop >>the other uhci driver over time (2.5 maybe) >> > >i'd just thought i'd verify that usb-uchi seems to be causing >some havoc on SMP boxes. > >i've had complete crashes (Alt-SysRq-s doesn't respond) when i >try to print stuff to a USB printer using the usb-uchi and >printer modules. this is on an SMP box. > >however -- 2.4.2 works perfectly for that. it broke from 2.4.4 >onward (tried 2.4.[5-7], i'm presuming .8 hasn't fixed the >problem.) > >if anybody wants me to help them diagnose the problem, i'd be >more than happy to, but i'm not sure where to start at the >moment. > Note the usb sound driver does that same thing even on a UP box (with SMP kernel and UP kernel) I've tried to debug the problem but setting nmi_watchdog=1 at boot time does seem to catch the problem so I don't have much to go on. If you haven't set nmi_watchdog yet you may want to try it and see if you have better luck. And yes comfirmed 2.4.3 works 2.4.[45678] does not. -Russell Cattelan