From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jonathan Nieder Subject: Re: [RFC/PATCH] Revert "Input: wacom - add 0xE5 (MT device) support" Date: Sat, 16 Jun 2012 17:25:45 -0500 Message-ID: <20120616222545.GA1660@burratino> References: <1335402856-11256-1-git-send-email-pinglinux@gmail.com> <20120614212335.GA4210@burratino> <20120615002705.GA7140@burratino> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-ob0-f174.google.com ([209.85.214.174]:60786 "EHLO mail-ob0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756892Ab2FPWZy (ORCPT ); Sat, 16 Jun 2012 18:25:54 -0400 Received: by obbtb18 with SMTP id tb18so6085227obb.19 for ; Sat, 16 Jun 2012 15:25:53 -0700 (PDT) Content-Disposition: inline In-Reply-To: Sender: linux-input-owner@vger.kernel.org List-Id: linux-input@vger.kernel.org To: Ping Cheng Cc: dmitry.torokhov@gmail.com, =?utf-8?B?QmrDuHJu?= Mork , linux-input@vger.kernel.org, Jason Gerecke , Chris Bagwell , Nils Kanning Hi Ping, Ping Cheng wrote: > Here is an update on my testing (for hardware, I have to test to be > sure). The result shows driver in upstream and 3.2.20 both work with > TPC2FG. Again, thanks much for this. Nils (cc-ed) tested Linus's "master" branch (3.5-rc2+) this morning. The outcome: | I built the kernel from the git repository as you described. The tablet | does not work. | | lsusb -t gives: | Port 5: Dev 5, If 0, Class=HID, Driver=, 12M | | The dmesg output is attached. The two input files mentioned in this | file, which are related to the wacom tablet, are not there after | booting. Logs at [1]. For comparison, v3.4.2 works fine. v3.4.2 plus some unrelated Intuous5 support patches (9fee619505bd + f860e581fd47 + 9b5b95dd516a + ae584ca47328) also works fine. Nils also tested v3.4.2 plus the following patch. f393ee2b814e Input: wacom - retrieve maximum number of touch points from the HID usage table when it is supported The exact patch used is at [2]. That produced: | Linux video capture interface: v2.00 | ------------[ cut here ]------------ | kernel BUG at mm/slab.c:505! | invalid opcode: 0000 [#1] SMP [...] | Pid: 579, comm: modprobe Not tainted 3.4.2-amd64 #1 LENOVO 42992QG/42992QG [...] | Call Trace: | [] ? kfree+0x50/0x6c | [] ? wacom_probe+0x52c/0x957 [wacom] | [] ? usb_probe_interface+0xf2/0x15d [usbcore] which is "BUG_ON(!PageSlab(page))" in page_get_cache() and represents a free of an invalid pointer. Full log at [3]. Known problem? Any ideas for tracking it down? Thanks again and hope that helps, Jonathan [1] http://bugs.debian.org/677164#87 [2] http://bugs.debian.org/677164#50 [3] http://bugs.debian.org/cgi-bin/bugreport.cgi?msg=77;filename=dmesg_0001;att=1;bug=677164