From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH 3/3] libata-dev: Fix pdc2027x ATAPI DMA lost irq problem Date: Wed, 10 Aug 2005 23:05:43 -0400 Message-ID: <42FAC087.2000800@pobox.com> References: <42F24DBE.0@tw.ibm.com> <42F252ED.8020206@tw.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail.dvmed.net ([216.237.124.58]:60834 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S932233AbVHKDFq (ORCPT ); Wed, 10 Aug 2005 23:05:46 -0400 In-Reply-To: <42F252ED.8020206@tw.ibm.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Albert Lee Cc: Linux IDE , Doug Maxey , Bartlomiej Zolnierkiewicz Albert Lee wrote: > Jeff, > > Patch 3/3: Fix pdc2027x ATAPI DMA lost irq problem > > Description: > Sometimes pdc2027x will lost irq after ATAPI DMA data transfer. > With the previous rule (cmd->request_bufflen % 256), the ATAPI DMA irq > lost > problem still occurs during the test. > > Root cause for the irq lost is unknown. I've tried your ATAPI DMA > alignment > patch, but the problem still occurs, even the buffer is aligned. I guess > it is pdc2027x hardware problem. > > The following workarounds are adapted from the Promise pdc618 GPL driver. > They seems know about the problem and has the workaround. I think this needs to be investigated a bit more, but the pdc618 driver does it, we may need to do this eventually. Jeff