From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752817Ab0HGPrh (ORCPT ); Sat, 7 Aug 2010 11:47:37 -0400 Received: from he.sipsolutions.net ([78.46.109.217]:34132 "EHLO sipsolutions.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752140Ab0HGPrf (ORCPT ); Sat, 7 Aug 2010 11:47:35 -0400 Subject: Re: [PATCH 1/1] integer overflow issue in 'appletouch' driver From: Johannes Berg To: Serge Belyshev Cc: Vadim Zaliva , Dmitry Torokhov , linux-kernel@vger.kernel.org, Benjamin Herrenschmidt In-Reply-To: <87k4o234lx.fsf@depni.sinp.msu.ru> References: <1268034117.3819.1.camel@jlt3.sipsolutions.net> <36779F26-DB1B-46ED-8635-01B03E559B55@crocodile.org> <20100310062227.GB2445@core.coreip.homeip.net> <87k4o234lx.fsf@depni.sinp.msu.ru> Content-Type: text/plain; charset="UTF-8" Date: Sat, 07 Aug 2010 17:47:30 +0200 Message-ID: <1281196050.4431.4.camel@jlt3.sipsolutions.net> Mime-Version: 1.0 X-Mailer: Evolution 2.30.2 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 2010-08-07 at 14:00 +0000, Serge Belyshev wrote: > Hi! > > Since 2.6.34 the touchpad on my feb 2005 powerbook (mod. A1106) has > stopped working. I've identified the following guilty patch: > > http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=04b4b88cca0ebe3813b4b6f014fb6a0db380b137 > > > ... Testing on one of such PowerBooks I have > > noticed that touchpad always generates positive values, but some of > > them are greater that 127, and thus, when cast to 'signed char' being > > interpreted as a negative. > > My device is 05ac:020e "fountain", actually generates *signed* values, > thus the patch completely breaks it. I think Ben might have the same issue. I guess we need per-touchpad functions to read the data. johannes