From mboxrd@z Thu Jan 1 00:00:00 1970 From: Albert Lee Subject: Re: libata machine check on Alpha Date: Thu, 06 Apr 2006 10:04:03 +0800 Message-ID: <44347713.9000408@tw.ibm.com> References: <2E9B8131C44AF746B1E06BF9B15A434B045D8198@mail.siliconimage.com> Reply-To: albertl@mail.com Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from e35.co.us.ibm.com ([32.97.110.153]:27596 "EHLO e35.co.us.ibm.com") by vger.kernel.org with ESMTP id S1751233AbWDFCEd (ORCPT ); Wed, 5 Apr 2006 22:04:33 -0400 Received: from westrelay02.boulder.ibm.com (westrelay02.boulder.ibm.com [9.17.195.11]) by e35.co.us.ibm.com (8.12.11.20060308/8.12.11) with ESMTP id k3624NFg026360 for ; Wed, 5 Apr 2006 22:04:23 -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 k36210OS273640 for ; Wed, 5 Apr 2006 20:01:02 -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 k3624KSJ008162 for ; Wed, 5 Apr 2006 20:04:21 -0600 In-Reply-To: <2E9B8131C44AF746B1E06BF9B15A434B045D8198@mail.siliconimage.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Carlos Pardo Cc: Tejun Heo , Jonathan Blake Benson , linux-ide@vger.kernel.org, Jeff Garzik Carlos Pardo wrote: > The 3611 bridge does not support the ATAPI DMA direction bit in hardw= are.(software support only) =20 >=20 > The 3811 bridge supports ATAPI DMA direction bit in both software and= hardware. >=20 > The 646 chip is ancient and he should upgrade. The behavior of this = device is unknown since this part was EOL'd years ago. >=20 >=20 Hi Carlos, Does this mean that only the 3611 bridge needs the DMA_DIR bit set by h= ost software, while 3811 can detect the ATAPI DMA direction by hardware and doesn't need the DMA= _DIR bit? (I guess that 3811 detects the direction by looking into the SCSI CDB. = If the SCSI command is unknown to it, 3811 still needs the DMA_DIR bit set by software.) Is there anyway that we could detect whether the DMA_DIR needs to be se= t by host software? Is there anyway that we could detect whether the bridge is a 3611 or a = 3811 chip automatically? Per Jeff's comment, there is a document on t13 (http://www.t13.org/docs= 2003/e03131r0.pdf). The documents reads: "Eg. =96 Word 50, bit 13: Set to 1 for devices that support DMAIN bit i= n Features Register for Packet Command". However, this looks more for the ATAPI device than for the bridge? Also it looks not a t13 standard yet? Can we use this word 50 to identify 3611/3811? Thanks, Albert