Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S964829AbVI2Thy (ORCPT ); Thu, 29 Sep 2005 15:37:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S964852AbVI2Thx (ORCPT ); Thu, 29 Sep 2005 15:37:53 -0400 Received: from willy.net1.nerim.net ([62.212.114.60]:43526 "EHLO willy.net1.nerim.net") by vger.kernel.org with ESMTP id S964829AbVI2Thu (ORCPT ); Thu, 29 Sep 2005 15:37:50 -0400 Date: Thu, 29 Sep 2005 21:32:25 +0200 From: Willy Tarreau To: Arjan van de Ven Cc: SCSI Mailing List , Linus Torvalds , Andrew Morton , Linux Kernel Mailing List , Luben Tuikov , Jeff Garzik Subject: Re: I request inclusion of SAS Transport Layer and AIC-94xx into the kernel Message-ID: <20050929193225.GA16171@alpha.home.local> References: <43384E28.8030207@adaptec.com> <4339BFE9.1060604@pobox.com> <4339CCD6.5010409@adaptec.com> <4339F9A8.2030709@pobox.com> <433AFEB2.7090003@adaptec.com> <433B0457.7020509@pobox.com> <433B14E1.6080201@adaptec.com> <433B217F.4060509@pobox.com> <20050929040403.GE18716@alpha.home.local> <1127979848.2918.7.camel@laptopd505.fenrus.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1127979848.2918.7.camel@laptopd505.fenrus.org> User-Agent: Mutt/1.5.10i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2107 Lines: 45 On Thu, Sep 29, 2005 at 09:44:08AM +0200, Arjan van de Ven wrote: > On Thu, 2005-09-29 at 06:04 +0200, Willy Tarreau wrote: > > On Wed, Sep 28, 2005 at 07:04:31PM -0400, Jeff Garzik wrote: > > > Linux is about getting things done, not being religious about > > > specifications. You are way too focused on the SCSI specs, and missing > > > the path we need to take to achieve additional flexibility. > > > > > > With Linux, it's all about evolution and the path we take. > > > > Hmmm... I'm fine with "not being religious about specs", but I hope we > > try to respect them as much as possible > > a spec describes how the hw works... how we do the sw piece is up to > us ;) No Arjan, you cannot say that ! (well, of course you can but in this case you may be wrong). A spec describes any process, whether it's soft or hard, and BTW, the frontier between soft and hard is diminishing. When I designed a PI-Bus-PCI bridge 10 years ago, I used PCI 2.1 Specification. And it was more related to software than hardware (FSMs, config registers, etc...). It's the *implementation* which is up to us, not the spec. A spec will never tell you that you have to be compliant with 4k stacks or things like this. This is implementation. What it tells you is when interrupt X strikes and you read bit Y from reg Z, then you must reset bit Y before leaving. And this is software specs, not hardware. > (I know the scsi stuff also provides sort of a reference "here is how > you can do it in sw" but I see that more as you "you need this > functionality" not "you need this exact architecture in your software") Keeping close to an accepted standard model makes it far easier to upgrade later, but you're right, the spec does not tell you what your implementation must look like. I think we agree but just don't give the exact same meaning to words. Regards, Willy - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/