From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 77FEC12838B; Thu, 4 Apr 2024 13:52:46 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.176.79.56 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712238769; cv=none; b=UDsQISV6OFnRutT6a4tLHUk1PPJvKudhAVYekD8Rcq8Dx3CkBeTr/3csBjDj4U0UeOzPhTUj2PlxvpXCBys8Xm9LLz5zAkAyrZfm6dMDiQZOsn2bquWBqVWRxIN+Kyj/uRePtucVhc9++qaKJf2iNTNG+PeYuoY15oFocBJeshc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712238769; c=relaxed/simple; bh=p/xIWORqgT6hpFpXe4AVo+Pf1rB1FZaKpn1vwwBA98g=; h=Date:From:To:CC:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ODFHhLO47IVyTWDTrRy3B9y+zSpN+U1/772omIQjRoQ/QADC7sqllvAoy/+7peL7KqkuRYqrqt2M5CSmI175FCOAtvZkZ/P5K5ezmsSXlPZXsjoFRN0MimZc88xTQYIlzscGf7SzpRFb3rsM0wRxpIaVOMu7PRX2S0c47uIOx1U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=Huawei.com; spf=pass smtp.mailfrom=huawei.com; arc=none smtp.client-ip=185.176.79.56 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=Huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Received: from mail.maildlp.com (unknown [172.18.186.216]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4V9NH84qjrz6J7Df; Thu, 4 Apr 2024 21:48:04 +0800 (CST) Received: from lhrpeml500005.china.huawei.com (unknown [7.191.163.240]) by mail.maildlp.com (Postfix) with ESMTPS id D9C43140C72; Thu, 4 Apr 2024 21:52:43 +0800 (CST) Received: from localhost (10.202.227.76) by lhrpeml500005.china.huawei.com (7.191.163.240) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2507.35; Thu, 4 Apr 2024 14:52:43 +0100 Date: Thu, 4 Apr 2024 14:52:42 +0100 From: Jonathan Cameron To: Lukas Wunner CC: Dan Williams , Bjorn Helgaas , Dave Jiang , , , , , , , Subject: Re: [PATCH v2 1/3] PCI: Add check for CXL Secondary Bus Reset Message-ID: <20240404145242.00002dd8@Huawei.com> In-Reply-To: References: <6605bef53c82b_1fb31e29481@dwillia2-xfh.jf.intel.com.notmuch> <20240402172323.GA1818777@bhelgaas> <660c44604f0a3_19e029497@dwillia2-mobl3.amr.corp.intel.com.notmuch> <20240403154441.00002e30@Huawei.com> Organization: Huawei Technologies Research and Development (UK) Ltd. X-Mailer: Claws Mail 4.1.0 (GTK 3.24.33; x86_64-w64-mingw32) Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit X-ClientProxiedBy: lhrpeml100003.china.huawei.com (7.191.160.210) To lhrpeml500005.china.huawei.com (7.191.163.240) On Thu, 4 Apr 2024 11:02:10 +0200 Lukas Wunner wrote: > On Wed, Apr 03, 2024 at 03:44:41PM +0100, Jonathan Cameron wrote: > > > Bjorn Helgaas wrote: > > > > FWIW, I pinged administration@pcisig.com and got the response that > > > > "1E98h is not a VID in our system, but 1E98 has already been reserved > > > > by CXL." > > > > > > > > I wish there were a clearer public statement of this reservation, but > > > > I interpret the response to mean that CXL is not a "Vendor", maybe due > > > > to some strict definition of "Vendor," but that PCI-SIG will not > > > > assign 0x1e98 to any other vendor. > > > > > > > > So IMO we should add "#define PCI_VENDOR_ID_CXL 0x1e98" so that if we > > > > ever *do* see such an assignment, we'll be more likely to flag it as > > > > an issue. > > > > Sorry for late entry on this discussion and I'll be careful what I say > > on the history. > > > > As you've guessed it was "entertaining" and for FWIW that text occurs > > in other consortium specs (some predate CXL). > > > > It's reserved with agreement from the PCI SIG for a strictly defined set > > of purposes that does not correspond to those allowed for a normal ID > > granted to a vendor member. As you say CXL isn't a vendor (don't ask > > how DMTF got a vendor ID - 0x1AB4). > > > > Hence the naming gymnastics and vague answers to avoid any chance of > > lawyers getting involved :( > > Hm, I'm wondering if avoiding the term "vendor" with something like > > #define PCI_CONSORTIUM_ID_CXL 0x1e98 > > would assuage the angst of a legal misstep? ;) Works for me, but I really hope we don't have to care :( Jonathan