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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 3AFC5C0044C for ; Wed, 7 Nov 2018 23:30:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 00C6F2085B for ; Wed, 7 Nov 2018 23:30:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 00C6F2085B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.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 S1726982AbeKHJDe (ORCPT ); Thu, 8 Nov 2018 04:03:34 -0500 Received: from mga12.intel.com ([192.55.52.136]:20818 "EHLO mga12.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726191AbeKHJDd (ORCPT ); Thu, 8 Nov 2018 04:03:33 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga106.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 07 Nov 2018 15:30:53 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.54,477,1534834800"; d="scan'208";a="84157434" Received: from spandruv-mobl.amr.corp.intel.com ([10.254.10.84]) by fmsmga007.fm.intel.com with ESMTP; 07 Nov 2018 15:30:53 -0800 Message-ID: <9e4da173ba2978e1c16839162dd927c5ea0fdc36.camel@linux.intel.com> Subject: Re: [PATCH 2/4] x86/amd_nb: add support for newer PCI topologies From: Srinivas Pandruvada To: Bjorn Helgaas Cc: Borislav Petkov , "Woods, Brian" , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , "x86@kernel.org" , Clemens Ladisch , Jean Delvare , Guenter Roeck , Pu Wen , Jia Zhang , Takashi Iwai , Andy Whitcroft , Colin Ian King , Myron Stowe , Sumeet Pawnikar , "linux-kernel@vger.kernel.org" , "linux-hwmon@vger.kernel.org" , "linux-pci@vger.kernel.org" Date: Wed, 07 Nov 2018 15:30:52 -0800 In-Reply-To: <20181107231411.GB41183@google.com> References: <20181102195925.GB160487@google.com> <20181102232948.GC26770@zn.tnic> <20181105214537.GA19420@google.com> <20181105215650.GG26868@zn.tnic> <20181106214256.GA65443@google.com> <20181106220059.GA4139@zn.tnic> <20181106232040.GA85755@google.com> <75748b089ee696d5cbaa5c0ce68bad228699894c.camel@linux.intel.com> <20181107213103.GA41183@google.com> <20181107231411.GB41183@google.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.28.5 (3.28.5-1.fc28) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org [...] > Sure, you can't *force* OEMs to supply a given ACPI device, but you > can certainly say "if you want this functionality, supply INT3401 > devices." That's what you do with PNP0A03 (PCI host bridges), for > example. If an OEM doesn't supply PNP0A03 devices, the system can > boot just fine as long as you don't need PCI. > > This model of using the PCI IDs forces OS vendors to release updates > for every new platform. I guess you must have considered that and > decided whatever benefit you're getting was worth the cost. Not worth cost. This is a pain. Every release we end up adding a single line change to many drivers adding a PCI device id. Since there is no unique class_mask for PCI device for these devices, we need to add device_id for each generation even if there is no change. Instead if we have some feature to say don't enumerate for PCI device id < X and a black list, it will save lot of work. Thanks, Srinivas