From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161491AbWAMIaQ (ORCPT ); Fri, 13 Jan 2006 03:30:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161492AbWAMIaQ (ORCPT ); Fri, 13 Jan 2006 03:30:16 -0500 Received: from 203-79-122-66.cable.paradise.net.nz ([203.79.122.66]:9819 "EHLO kereru.site") by vger.kernel.org with ESMTP id S1161491AbWAMIaO (ORCPT ); Fri, 13 Jan 2006 03:30:14 -0500 Date: Fri, 13 Jan 2006 21:30:09 +1300 From: Volker Kuhlmann To: linux-kernel Subject: Re: ide-cd turning off DMA when verifying DVD-R Message-ID: <20060113083009.GE12338@paradise.net.nz> References: <5ujmU-1UQ-665@gated-at.bofh.it> <5uoqr-Qq-7@gated-at.bofh.it> <43C72F41.5060207@shaw.ca> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <43C72F41.5060207@shaw.ca> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri 13 Jan 2006 17:40:33 NZDT +1300, Robert Hancock wrote: > I'm thinking the IDE code is too aggressive in assuming that the failure > is because of a DMA problem and disabling it.. Most likely all that's > happening is the drive is taking a long time to complete the current > command. Yes! Each time when inserting a faulty CD/DVD, or whenever the drive gives read errors for whatever reason, the kernel decides to turn DMA off and try again, fail (again) and leave DMA off. And this after having successfully used DMA before - so it's not that the device is DMA-incapable. Volker -- Volker Kuhlmann is possibly list0570 with the domain in header http://volker.dnsalias.net/ Please do not CC list postings to me.