From mboxrd@z Thu Jan 1 00:00:00 1970 From: Albert Lee Subject: Re: [PATCH/RFC] libata: turn on the ATAPI DMA DIR support per word 62 Date: Fri, 07 Apr 2006 18:21:34 +0800 Message-ID: <44363D2E.7010700@tw.ibm.com> References: <44360922.8050801@tw.ibm.com> <44360B05.6050509@garzik.org> Reply-To: albertl@mail.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from e32.co.us.ibm.com ([32.97.110.150]:61656 "EHLO e32.co.us.ibm.com") by vger.kernel.org with ESMTP id S1751124AbWDGKWB (ORCPT ); Fri, 7 Apr 2006 06:22:01 -0400 Received: from westrelay02.boulder.ibm.com (westrelay02.boulder.ibm.com [9.17.195.11]) by e32.co.us.ibm.com (8.12.11.20060308/8.12.11) with ESMTP id k37ALtMI023924 for ; Fri, 7 Apr 2006 06:21:55 -0400 Received: from d03av03.boulder.ibm.com (d03av03.boulder.ibm.com [9.17.195.169]) by westrelay02.boulder.ibm.com (8.12.10/NCO/VER6.8) with ESMTP id k37AIWTA260026 for ; Fri, 7 Apr 2006 04:18:33 -0600 Received: from d03av03.boulder.ibm.com (loopback [127.0.0.1]) by d03av03.boulder.ibm.com (8.12.11/8.13.3) with ESMTP id k37ALsUD025530 for ; Fri, 7 Apr 2006 04:21:55 -0600 In-Reply-To: <44360B05.6050509@garzik.org> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Jeff Garzik Cc: linux-ide@vger.kernel.org, Jonathan Benson , Tejun Heo , Carlos Pardo , Doug Maxey Jeff Garzik wrote: > > Two comments: > > * I would like to find a device that's compliant with the spec, and test > the patch, before committing. I'm trying to get an Acard AEC-7900A and a Sunplus 3811A (which looks like a SiI 3811 rebrand) for test. Since the DMADIR is SiImage's idea, hopefully the Sunplus 3811A may support DMADIR. For bridges from other vendors, I guess the chance is low. > > * DMADIR not only includes a bit flag indicating its presence, it also > moves all the DMA capability bits from their standard places. You'll > have to audit every place that reads dev->id[]'s mwdma/udma masks and > make sure they look at the DMADIR-special-case location, when DMADIR is > set. > Fortunately only ata_id_xfermask() uses the mwdma/udma bits. Revised patch to follow. Thanks for the advice. -- albert