From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 65568C8301D for ; Mon, 23 Nov 2020 13:04:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3C0C820782 for ; Mon, 23 Nov 2020 13:04:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="iSoNo6kW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388345AbgKWNEU (ORCPT ); Mon, 23 Nov 2020 08:04:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59020 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1733296AbgKWMvR (ORCPT ); Mon, 23 Nov 2020 07:51:17 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DD667C061A4E for ; Mon, 23 Nov 2020 04:51:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=hGwFFxZDkfTKMpVUin8IwCyLR1ox8ZPJ5jRaHO73hOQ=; b=iSoNo6kWPZojll+FQV7dP7Wa+u 8ttxGdC1m8/nivfbbenIuaQdQNCecojUwkypaLqaZU4AEmgF6YqkK2omqBMcdbacqQZ01Wr7y01SZ eEv0Rb+vGtgM9i52mj/JcFs6R3P+QWwK3Lv1l2DIZHcZj6X/M5yeIrBdNDJJ41f/Jr4lXjFcPsjoE d5aRJ/pD2a025qydKZQIFFTxT1inDDTN62mxU3xXDRzYlVM362ESUtK2y3gV6Y+BdUNcgul37Wmsl 2oJOVlUlkdCDyVE6iw54pQRNo6ZTTKKGQd9mw2KbKxM/9HCvfp+58XFFCIpI1UMzt04V/gXv/QNpV k2A66cow==; Received: from hch by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1khBJK-00017g-Nq; Mon, 23 Nov 2020 12:51:14 +0000 Date: Mon, 23 Nov 2020 12:51:14 +0000 From: Christoph Hellwig To: Mika Westerberg Cc: Christoph Hellwig , Jens Axboe , linux-ide@vger.kernel.org Subject: Re: [PATCH] ahci: Add Intel Emmitsburg PCH RAID PCI IDs Message-ID: <20201123125114.GA4264@infradead.org> References: <20201119104318.79297-1-mika.westerberg@linux.intel.com> <20201119165022.GA3582@infradead.org> <20201120105309.GR2495@lahna.fi.intel.com> <20201123100917.GA26718@infradead.org> <20201123112622.GB2495@lahna.fi.intel.com> <20201123113801.GA15759@infradead.org> <20201123122820.GD2495@lahna.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201123122820.GD2495@lahna.fi.intel.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Precedence: bulk List-ID: X-Mailing-List: linux-ide@vger.kernel.org On Mon, Nov 23, 2020 at 02:28:20PM +0200, Mika Westerberg wrote: > On Mon, Nov 23, 2020 at 11:38:01AM +0000, Christoph Hellwig wrote: > > The point is: these AHCI controllers do not support RAID in form > > despite the confusing naming. > > Are you sure? > > I looked at the Emmitsburg data sheet and it actually seems to support > some sort of RAID but it requires some special Rapid Storage Technology > [1] drivers from Intel. Probably the idea is that when in "RAID mode" > the thing, as AHCI spec says, does not announce itself to be AHCI > compliant which makes Windows inbox AHCI driver to not to load, and this > allows the Intel propriatery driver to load that then takes advantage of > this somehow. Yes, and that is purely (badly implemented) software RAID.