Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757332AbcCXOiP (ORCPT ); Thu, 24 Mar 2016 10:38:15 -0400 Received: from mx2.suse.de ([195.135.220.15]:44289 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752522AbcCXOiB (ORCPT ); Thu, 24 Mar 2016 10:38:01 -0400 Date: Thu, 24 Mar 2016 15:37:58 +0100 (CET) From: Jiri Kosina X-X-Sender: jkosina@pobox.suse.cz To: Ping Cheng cc: Laura Abbott , Ping Cheng , Jason Gerecke , linux-input , "linux-kernel@vger.kernel.org" , Benjamin Tissoires Subject: Re: [REGRESSION] panic with Wacom One Tablet on 4.4.x kernel In-Reply-To: Message-ID: References: <56E9D929.70101@redhat.com> User-Agent: Alpine 2.00 (LNX 1167 2008-08-23) 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: 884 Lines: 28 On Thu, 24 Mar 2016, Jiri Kosina wrote: > > Yes, please provide a bisect report so we get a clue. > > > > I do not have a "Wacom One". I have a Wacom Bamboo Pen, which goes > > through the same code base as "Wacom One". I tested kernel 4.4.4. I > > don't see the issue. > > Laura, do we have any result from the bisect please? BTW seems like wacom_get_report() got EPIPE and bailed out. We used to retry on EPIPE before aef3156d72. Would it make sense to retest with that commit reverted? Could be that the device is for some reason causing only temporary EPIPE that eventually gets fixed over time. I still don't exactly see how that'd cause the null pointer dereference later, but retval handling wacom_get_report() might possibly need some loving care as well, looking quickly at the code. But that still needs to be investigated. Thanks, -- Jiri Kosina SUSE Labs