From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Garzik Subject: Re: [PATCH] aic79xx should be able to ignore HostRAID enabled adapters Date: Thu, 01 Dec 2005 12:49:31 -0500 Message-ID: <438F37AB.5030800@pobox.com> References: <547AF3BD0F3F0B4CBDC379BAC7E4189F01E3E318@otce2k03.adaptec.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from mail.dvmed.net ([216.237.124.58]:6086 "EHLO mail.dvmed.net") by vger.kernel.org with ESMTP id S932350AbVLARtq (ORCPT ); Thu, 1 Dec 2005 12:49:46 -0500 In-Reply-To: <547AF3BD0F3F0B4CBDC379BAC7E4189F01E3E318@otce2k03.adaptec.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: "Salyzyn, Mark" Cc: Christoph Hellwig , "Darrick J. Wong" , Chris McDermott , Luvella McFadden , AJ Johnson , Kevin Stansell , linux-kernel@vger.kernel.org, linux-scsi@vger.kernel.org, Mauelshagen@redhat.com Salyzyn, Mark wrote: > Justin Gibbs had provided the community the emd driver, soundly rejected > and never ported to dm because there were features that Justin held dear > in md that do not translate to dm. An unfortunate waste of considerable > resources. All throughout development, before Justin had written a single line of code, he was told to do things via Device Mapper. All he had to do was open his ears, and no resource waste would have occurred. > Without the timely agenda and cooled temperaments to close the gap, the > solution should be temporarily to support the proprietary HostRAID > driver when the Adapter is in HostRAID mode and we continue to work to > close that gap on dmraid. [...] > They are plain SCSI HBAs, but are designated as a RAID card rather than > a Host Bus Adapter in the PCI config space when in 'HostRAID' mode. The > fact that is designated in the PCI space should be enough reason *not* > to attach a simplified LLD. Strongly disagree. Linux should export the [non-RAID] hardware capabilities, nothing more. We don't shim for not-in-tree binary-only drivers. A user continues to be free to simply -not use- aic79xx, regardless of this design decision. SATA controllers come with all sorts of class codes: RAID (host/fake raid), SCSI (fake RAID/fake scsi), IDE, Serial ATA. We ignore that, and just export the hardware. The class code is only a hint that dmraid should be loaded on top of the low-level driver. > Linux is not about performance first, it is about doing it the Linux > way. I believe we can understand that. And in turn, do not consider it > harmful if a group of individuals trying to make a living see a chance > to acquire a competitive edge. We don't do it "the Linux way" just for NIH's sake. There are strong reasons why we want cross-vendor solutions. There are strong reasons why we don't want every driver to embed a software RAID engine inside it. And there are strong reasons (some legal, not technical) why its best to ignore binary-only, out-of-tree drivers. Jeff