From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265045AbTL2Tnv (ORCPT ); Mon, 29 Dec 2003 14:43:51 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265117AbTL2Tnv (ORCPT ); Mon, 29 Dec 2003 14:43:51 -0500 Received: from ns.virtualhost.dk ([195.184.98.160]:41613 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S265045AbTL2Tmx (ORCPT ); Mon, 29 Dec 2003 14:42:53 -0500 Date: Mon, 29 Dec 2003 20:42:49 +0100 From: Jens Axboe To: craig duncan Cc: linux-kernel@vger.kernel.org Subject: Re: CD burn buffer underruns on 2.6 Message-ID: <20031229194249.GO3086@suse.de> References: <16366.60194.935861.592797@nycap.rr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <16366.60194.935861.592797@nycap.rr.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Dec 28 2003, craig duncan wrote: > My first attempts at burning on 2.6 resulted in a couple of coasters > (i'm running the "stock" 2.6 Debian kernel: kernel-image-2.6.0-test9-1-386). > Burn speed was 8x (max speed for my PleXwrite 8/4/32A). With the 2.4 > kernel (2.4.22-1-k7 on a 1.3 gig Athlon) i never had a problem burning > at 8x (in fact, when burning completes, it always tells me: > Buffer fill min 93%/max 100%. > > At 4x, burns on 2.6 work fine, though. At 8x, the burn always craps out > shortly after starting. This is completely consistent... 8x fails, 4x > works (see cdrdao output below). Nothing else is going on on my system. > Running as root or regular user doesn't matter. > > After a few of these failed burns ("cdrdao simulate...", actually) i saw > this in /var/log/kern.log: > > Dec 24 08:24:44 cdw kernel: cdrom_newpc_intr: 110 residual after xfer > Dec 24 08:24:57 cdw kernel: cdrom_newpc_intr: 104 residual after xfer > Dec 24 08:25:43 cdw kernel: cdrom_newpc_intr: 110 residual after xfer > Dec 24 08:25:55 cdw kernel: cdrom_newpc_intr: 104 residual after xfer > Dec 24 08:26:52 cdw kernel: cdrom_newpc_intr: 110 residual after xfer > Dec 24 08:27:03 cdw kernel: cdrom_newpc_intr: 104 residual after xfer > > As a side note, under 2.6, i see these "resid: 110", "resid: 104", etc. > messages in the cdrdao output (below) which i never saw under 2.4. > > Here's my cdrdao output: > ----- > Starting write simulation resid: 110 > at speed 8... > Pausing 10 seconds - hit CTRL-C to abort. > Process can be aborted with QUIT signal (usually CTRL-\). > resid: 104 > Writing CD-TEXT lead-in... > Writing track 01 (mode AUDIO/AUDIO )... > Writing track 02 (mode AUDIO/AUDIO )... > ?: Success. : scsi sendcmd: no error > CDB: 2A 00 00 00 26 80 00 00 1A 00 > status: 0x2 (CHECK CONDITION) > Sense Bytes: F0 00 03 00 00 27 18 0A 00 00 00 00 0C 09 00 00 > Sense Key: 0x3 Medium Error, Segment 0 > Sense Code: 0x0C Qual 0x09 (write error - loss of streaming) Fru 0x0 > Sense flags: Blk 10008 (valid) > resid: 61152 > cmd finished after 0.014s timeout 180s > ERROR: Write data failed. > ERROR: Writing failed - buffer under run? > ERROR: Simulation failed. > > I looked through the kernel archives and didn't see anyone else > reporting this problem but it seems kind of serious to me. Maybe cdrdao doesn't align its buffers correctly? Can you send me a vmstat 1 output while attempting a 8x burn on 2.6? -- Jens Axboe