From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Richter Subject: Re: [PATCH] ieee1394: sbp2: lower block queue alignment requirement Date: Sun, 14 Jan 2007 21:14:15 +0100 (CET) Message-ID: References: <1168802387.2780.1.camel@mulgrave.il.steeleye.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1168802387.2780.1.camel@mulgrave.il.steeleye.com> Content-Disposition: INLINE List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux1394-devel-bounces@lists.sourceforge.net Errors-To: linux1394-devel-bounces@lists.sourceforge.net To: James Bottomley Cc: linux1394-devel@lists.sourceforge.net, linux-scsi@vger.kernel.org List-Id: linux-scsi@vger.kernel.org On 14 Jan, James Bottomley wrote: > The block layer currently provides sector (512) byte alignment > guarantees. However, there has been talk in SCSI of reducing that to > word (4) since that's what most intelligent PCI controllers can cope > with. If you have any alignment constraints, they should be expressed > in the slave configure. OK, thanks. I will keep the explicit setting of the mask then. I actually think that everything should work just fine with 4 bytes alignment, but the SBP-2 spec mentiones 8 bytes alignment for the S/G tables. So maybe device firmwares will expect it that way even though IEEE 1394 doesn't impose such a restriction even on transfers with a payload of a multiple of 8 bytes. -- Stefan Richter -=====-=-=== ---= -===- http://arcgraph.de/sr/ ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV