From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751033AbXDBADx (ORCPT ); Sun, 1 Apr 2007 20:03:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751121AbXDBADx (ORCPT ); Sun, 1 Apr 2007 20:03:53 -0400 Received: from smtpq1.groni1.gr.home.nl ([213.51.130.200]:37826 "EHLO smtpq1.groni1.gr.home.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751033AbXDBADx (ORCPT ); Sun, 1 Apr 2007 20:03:53 -0400 Message-ID: <4610481D.8000102@gmail.com> Date: Mon, 02 Apr 2007 02:02:37 +0200 From: Rene Herman User-Agent: Thunderbird 1.5.0.10 (X11/20070221) MIME-Version: 1.0 To: Pekka Enberg CC: Jens Axboe , Al Viro , Linux Kernel Subject: Re: mcdx -- do_request(): non-read command to cd!! References: <460D7F70.3090702@gmail.com> <20070331064711.GF6246@kernel.dk> <460EA727.8070306@gmail.com> <84144f020704010306q600f58ddge1d42753362cf4e2@mail.gmail.com> In-Reply-To: <84144f020704010306q600f58ddge1d42753362cf4e2@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit X-AtHome-MailScanner-Information: Please contact support@home.nl for more information X-AtHome-MailScanner: Found to be clean Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On 04/01/2007 12:06 PM, Pekka Enberg wrote: > Looks like mcdx_xfer is sleeping while holding q->queue_lock. The > attached (untested) patch should fix it. This (including your followup) does indeed avoid the traces in the kernel log, but unfortunately, the driver seems to need a bit more. This may be expected, I'm not sure: root@5va2:~# dd if=/dev/mcdx0 of=/dev/null bs=2048 0+0 records in 0+0 records out 0 bytes (0 B) copied, 0.000221955 seconds, 0.0 kB/s root@5va2:~# This I know isn't: root@5va2:~# readcd dev=/dev/mcdx0 f=/dev/null Segmentation fault root@5va2:~# (leaves a "note: readcd[1174] exited with preempt_count 1" in the log) and after a "mount -t iso9660 /dev/mcdx0 /mnt/cdrom", a: root@5va2:~# tar cv /mnt/cdrom >/dev/null has upto now done all of: 1) segfault 2) make the kernel oops 3) reset the machine This thing is just so badly broken... ;-( I've attached the current patches from Jens and yourself (against 2.6.20.4) as a double check, but the driver's still totally unuseable even with them... I own two other legacy drives; a Panasonic CR562 (sbpcd.c) and a Sony CDU33A (cdu31a.c) which together with this Mitsumi LU005S (mcdx.c) make up also all but one of the controllers I have; a few standalone, but most on old ISA soundcards. When I last tested, cdu31a somewhat worked and sbpcd didn't. Had high hopes for mcdx.c upon seeing it compile without warnings, but alas. Last time Al Viro suggested ripping them out, I slightly objected: http://lkml.org/lkml/2004/5/2/123 but well, although I like playing with this stuff, I still don't know the first thing about the block layer and given the shape these things are in... Many thanks for looking though! Rene.