From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH] libata DMADIR support Date: Mon, 17 May 2004 15:08:06 -0400 Sender: linux-ide-owner@vger.kernel.org Message-ID: <40A90D96.2040002@pobox.com> References: <1084717146.3576.3.camel@patibmrh9> <40A7F641.3070809@pobox.com> <1084819720.4328.86.camel@patibmrh9> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:40598 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S262205AbUEQTIY (ORCPT ); Mon, 17 May 2004 15:08:24 -0400 In-Reply-To: <1084819720.4328.86.camel@patibmrh9> List-Id: linux-ide@vger.kernel.org To: Pat LaVarre Cc: linux-ide@vger.kernel.org Pat LaVarre wrote: > I remember I promised cross-references into the t13.org theories. Over > time I hope to walk back thru ATA/PI 7, 6, 5, and 4. Here first is most > of a DMADIR grep in ATA/PI 7, quoted below. Under the "documents 2003" link on http://www.t13.org/ there is also the original Silicon Image proposal: ATAPI DMA Direction issues Proposal 12/21/03 Hartney http://www.t13.org/docs2003/e03132r3.pdf Though the latest rev of ATA/ATAPI7 docs are probably a more up-to-date guide. > If bit 15 of word 62 is cleared to 0, DMADIR bit in the PACKET command > is not required. If bit 15 of word 62 is cleared to zero, then all bits > of word 62 shall be cleared to zero. I bet your bridge doesn't _require_ DMADIR, therefore it doesn't bother with word 62? Jeff