Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757946AbXHPMMU (ORCPT ); Thu, 16 Aug 2007 08:12:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752246AbXHPMMG (ORCPT ); Thu, 16 Aug 2007 08:12:06 -0400 Received: from moutng.kundenserver.de ([212.227.126.187]:62302 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752215AbXHPMME (ORCPT ); Thu, 16 Aug 2007 08:12:04 -0400 From: Bodo Eggert <7eggert@gmx.de> Subject: Re: Bad CD disk disables IDE DMA To: Michal Piotrowski , Zoltan Boszormenyi , linux-kernel , IDE/ATA development list Reply-To: 7eggert@gmx.de Date: Thu, 16 Aug 2007 14:11:53 +0200 References: <8Squ5-2cU-19@gated-at.bofh.it> <8SIKl-5IK-13@gated-at.bofh.it> User-Agent: KNode/0.7.2 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7Bit Message-Id: X-be10.7eggert.dyndns.org-MailScanner-Information: See www.mailscanner.info for information X-be10.7eggert.dyndns.org-MailScanner: Found to be clean X-be10.7eggert.dyndns.org-MailScanner-From: 7eggert@gmx.de X-Provags-ID: V01U2FsdGVkX1+hzA6MPTkzfFc8cxqLLDH6axgYqqwN83rr/Z+ JyHW6gUU4jdzzJLAEa17CyE5FrAza19bppfGUy5e02Jt1Ep5M+ xmdqSv1aRHsyyWmkyNzPQ== Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1801 Lines: 41 Michal Piotrowski wrote: > On 15/08/07, Zoltan Boszormenyi wrote: >> I noticed that a bad CD of mine makes DMA disabled: [...] >> hda: cdrom_decode_status: error=0x40 { LastFailedSense=0x04 } >> ide: failed opcode was: unknown >> hda: DMA disabled >> hda: ide_intr: huh? expected NULL handler on exit >> hda: ATAPI reset complete >> >> Every time I put the said CD into to drive and DMA is on, I get the >> above messages. > > This might be intended. Maybe, and maybe only a certain effect might be intended. And maybe I can help by asking these questions: 1) Does disabling DMA fix the seek errors, or does it hide them by the PIO interfce not printing them? 2) If it does hide them, would filtering for seek errors be a sane thing to do, or does the DMA engine (or HDD) behave badly on these errors, or do bad-DMA devices report seek errors, too? 3) If it does not hide them, would re-enabling DMA on disk change be a feasable workaround? (proposed interface: use hdparm -d $num where $num = 0, 1: as before 3: DMA on, if switched off automatically, will be set to 2 2: DMA off, will be turned on (set to 3) on disk change) 4) Does libata work well enough for making all effort put into that old IDE layer be a waste of time? -- Fun things to slip into your budget True: NASA couldn't get money approved for hangars for Space Shuttle so they put in request for 'Space Vehicle Refurbishment and Storage Facilities' - and got the money to build hangars - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/