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=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 EF7D6C43441 for ; Tue, 13 Nov 2018 11:45:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B19EF208E7 for ; Tue, 13 Nov 2018 11:45:53 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B19EF208E7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-pci-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726459AbeKMVni (ORCPT ); Tue, 13 Nov 2018 16:43:38 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:53526 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726424AbeKMVnh (ORCPT ); Tue, 13 Nov 2018 16:43:37 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 29468EBD; Tue, 13 Nov 2018 03:45:52 -0800 (PST) Received: from e107981-ln.cambridge.arm.com (e107981-ln.cambridge.arm.com [10.1.197.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 12ADF3F5CF; Tue, 13 Nov 2018 03:45:48 -0800 (PST) Date: Tue, 13 Nov 2018 11:45:36 +0000 From: Lorenzo Pieralisi To: Mika Westerberg Cc: Lukas Wunner , iommu@lists.linux-foundation.org, Joerg Roedel , David Woodhouse , Lu Baolu , Ashok Raj , Bjorn Helgaas , "Rafael J. Wysocki" , Jacob jun Pan , Andreas Noever , Michael Jamet , Yehezkel Bernat , Christian Kellner , Mario.Limonciello@dell.com, Anthony Wong , linux-acpi@vger.kernel.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/4] PCI / ACPI: Identify external PCI devices Message-ID: <20181113114527.GA12821@e107981-ln.cambridge.arm.com> References: <20181112160628.86620-1-mika.westerberg@linux.intel.com> <20181112160628.86620-2-mika.westerberg@linux.intel.com> <20181112180203.lx72gjfplb6xlur7@wunner.de> <20181113105636.GB11202@e107981-ln.cambridge.arm.com> <20181113112700.GT2500@lahna.fi.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20181113112700.GT2500@lahna.fi.intel.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Tue, Nov 13, 2018 at 01:27:00PM +0200, Mika Westerberg wrote: [...] > > To be frank the concept (and Microsoft _DSD bindings) seems a bit vague > > and not thoroughly defined and I would question its detection at > > PCI/ACPI core level, I would hope this can be clarified at ACPI > > specification level, at least. > > I guess that is the way they envision to use _DSD. Instead of having > single UUID that covers all properties (like what we have with device > properties) they have one UUID per property "class". I certainly hope we > don't need to keep extending prp_guids[] array each time they invent > another "class" of properties. It is even worse than that. This is a unilateral/obscure change that won't be part of ACPI specifications (I guess it was easier to add a UUID than add this to the ACPI specifications through the AWSG) but it is still supposed to be applicable to ACPI PCI bindings on any platforms/arches; this way of adding bindings does not work and it has to be rectified. Lorenzo