Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965231AbcKWPCn (ORCPT ); Wed, 23 Nov 2016 10:02:43 -0500 Received: from netrider.rowland.org ([192.131.102.5]:36009 "HELO netrider.rowland.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S964926AbcKWPCk (ORCPT ); Wed, 23 Nov 2016 10:02:40 -0500 Date: Wed, 23 Nov 2016 10:02:39 -0500 (EST) From: Alan Stern X-X-Sender: stern@netrider.rowland.org To: =?ISO-8859-1?Q?Bj=F8rn_Mork?= cc: wim@djo.tudelft.nl, Oliver Neukum , poma , , Subject: Re: crash by cdc_acm driver in kernels 4.8-rc1/5 In-Reply-To: <75DD0AB6-57EB-46F4-B608-4E73EACA4562@mork.no> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 902 Lines: 26 On Wed, 23 Nov 2016, [ISO-8859-1] Bj?rn Mork wrote: > On November 23, 2016 1:54:57 AM CET, Wim Osterholt wrote: > >On Tue, Nov 22, 2016 at 07:08:30PM +0100, Bjørn Mork wrote: > >> > On kernel 4.8.8 this crashes hard and produces over a serial link: > >> > >> Huh? That device shouldn't ever enter that code path AFAICS. > >> Unless.... you wouldn't happen to add a dynamic entry for this > >device, > > > >No idea of what you mean here. > > > >> would you? What's the output of > >> > >> cat /sys/bus/usb/drivers/cdc_acm/new_id > > > >Just empty. > > Shit. Back to not understanding how you could possibly enter the debugging code at all. You're in the lucky position of having an engaged and responsive bug reporter who is willing to apply patches and run tests. Just write a simple diagnostic patch that will reveal exactly what pathway is being followed. Alan Stern