From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Proposals to change the way all drivers work with SCSI commands Date: Fri, 11 May 2007 13:33:41 -0500 Message-ID: <1178908422.3692.58.camel@mulgrave.il.steeleye.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from hancock.steeleye.com ([71.30.118.248]:51401 "EHLO hancock.sc.steeleye.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1761683AbXEKSdo (ORCPT ); Fri, 11 May 2007 14:33:44 -0400 Received: from [172.17.6.40] (midgard.sc.steeleye.com [172.17.6.40]) by hancock.sc.steeleye.com (8.11.6/8.11.6) with ESMTP id l4BIXgk20279 for ; Fri, 11 May 2007 14:33:42 -0400 Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: linux-scsi Right at the moment, we're planning to clean up the way SCSI drivers process commands. The proposals are essentially: 1. Get rid of the now unnecessary map_single path (every command is either zero transfer or scatter/gather) 2. use accessors to manipulate the SG lists (mainly so that we can alter the implementation without affecting the drivers) It strikes me that in all of this, we could also consider doing the DMA mapping inside the mid layer (instead of in every driver). This is essentially what libata is already doing ... leading to confusion in SCSI drivers that use libata for SATA. So what do people think about this? James