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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 BA2E3C2D0F4 for ; Wed, 8 Apr 2020 21:47:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7EA9420753 for ; Wed, 8 Apr 2020 21:47:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586382470; bh=NnShytSGeCEQechGUCI/Zae9u/PmtXA1+7fWrnwX/3Y=; h=Date:From:To:Cc:Subject:In-Reply-To:List-ID:From; b=1lR6558dHwqXIbWxevCkSLOR2FppdQVJmgyFfAOOo7/zgNmKIjUpyWkfzz0fhG0no rS1NQdO5yuvQIEbVgyDgICZOngk1xtzzAE15a8T6kpBu9pZPfWqZkRligRi84qMs8f T3qra/mLhYB2i7Y5YbA4QO70c1R3+P/nBZTyPzqk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726483AbgDHVrt (ORCPT ); Wed, 8 Apr 2020 17:47:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:50394 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726409AbgDHVrt (ORCPT ); Wed, 8 Apr 2020 17:47:49 -0400 Received: from localhost (mobile-166-175-188-68.mycingular.net [166.175.188.68]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id E0CF02074F; Wed, 8 Apr 2020 21:47:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1586382469; bh=NnShytSGeCEQechGUCI/Zae9u/PmtXA1+7fWrnwX/3Y=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=qV2EplEsNKg8oY/wLKvp1Uh5lgHp4qsVg2s3dXExzmSP+BMM9MARAN+69VTFHzK3B 1PJyLNNCZw8WQatnFja4VYE065T9iroyg93ZPv2LiyWCXzmGs7Vrn713iLgRgTDDsH UsIEg+u1mxNamiBGaFxdfjN13mpOQLmUnFV7+MZo= Date: Wed, 8 Apr 2020 16:47:47 -0500 From: Bjorn Helgaas To: Sean V Kelley Cc: mj@ucw.cz, linux-pci@vger.kernel.org Subject: Re: [RFC Patch 1/1] lspci: Add basic decode support for Compute eXpress Link Message-ID: <20200408214747.GA129363@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <1766804A-54D2-4977-975A-9E9F29EFC155@linux.intel.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Wed, Apr 08, 2020 at 02:12:45PM -0700, Sean V Kelley wrote: > On 8 Apr 2020, at 9:56, Bjorn Helgaas wrote: > > On Tue, Apr 07, 2020 at 05:09:59PM -0700, Sean V Kelley wrote: > > > +#define PCI_EVNDR_CXL_ID 0 > > > > Unused in this patch. Is this the DVSEC Vendor ID as described in > > PCIe r5.0, sec 7.9.6.2? Is 0 really the ID assigned for CXL? > > It is as described in the PCIe Spec. The DVSEC ID is set to 0x0 here to > advertise that this is a Flex Bus feature capability structure. It’s > assigned in table 58 “PCI Express DVSEC Register Settings for Flex Bus > Device” of the CXL 1.1 spec. It sounds like it's the "DVSEC ID" (not the "DVSEC Vendor ID") that is zero. That would make sense to me because the "DVSEC ID" is completely under vendor control. I would expect the "DVSEC Vendor ID" to be assigned by the PCI-SIG, and I would be surprised if they assigned zero to CXL. So I assume you'll eventually #define both IDs here and I won't be confused any more :) Thanks for proactively working on this support in lspci! Bjorn