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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E3AFDC433EF for ; Fri, 12 Nov 2021 17:25:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C5BF4610D0 for ; Fri, 12 Nov 2021 17:25:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233404AbhKLR1z (ORCPT ); Fri, 12 Nov 2021 12:27:55 -0500 Received: from mail.kernel.org ([198.145.29.99]:39132 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235458AbhKLR1y (ORCPT ); Fri, 12 Nov 2021 12:27:54 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id E51F560FE3; Fri, 12 Nov 2021 17:25:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1636737902; bh=SoXgrHClC00+SbuZ7huPC/6CYTPZ/iRLlOyzpg2cyIg=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=Nnh7Jaq9sGLzhdBpmd9emvUxgXc2d/crA9SGXwx5KmukEGlmtnGW+8quYpaYRv4sg vcnYOFdM+UTaLHcV0dMX1ZLs9atfIaGeNYEbtuKKsmDVcMi4kTSW3yEStiBWlLnXjS W87z/PpsfapyOUcE5HXF2h0BqRi7+HmLNVp08cKTYF3YmlJ65acUc1507XQeWjXFTu 04u0k3+ZaHvFaFLfkdb/TL/i65+1ixqaDM5YBT3VPnm0JaMaioK7fbcxRCY6ptkUpA 3oBwVppZOOnda4VPEu37HrN7/WcaRrh1/cDQV9V+6atnbd3Nm6fZbMAIpZ5G0kjXfx xWggYY83qm3Dw== Date: Fri, 12 Nov 2021 18:24:58 +0100 From: Marek =?UTF-8?B?QmVow7pu?= To: Pali =?UTF-8?B?Um9ow6Fy?= , Rob Herring Cc: devicetree@vger.kernel.org, PCI , Bjorn Helgaas Subject: Re: [PATCH dt + pci 1/2] dt-bindings: Add 'slot-power-limit-milliwatt' PCIe port property Message-ID: <20211112182458.51745d4d@thinkpad> In-Reply-To: <20211112171249.46xmj5zo3svm4qn2@pali> References: <20211031150706.27873-1-kabel@kernel.org> <20211112153208.s4nuckz7js4fipce@pali> <20211112171249.46xmj5zo3svm4qn2@pali> X-Mailer: Claws Mail 3.18.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Fri, 12 Nov 2021 18:12:49 +0100 Pali Roh=C3=A1r wrote: > On Friday 12 November 2021 10:30:01 Rob Herring wrote: > > On Fri, Nov 12, 2021 at 9:32 AM Pali Roh=C3=A1r wrote= : =20 > > > > > > On Friday 12 November 2021 09:25:20 Rob Herring wrote: =20 > > > > On Sun, Oct 31, 2021 at 04:07:05PM +0100, Marek Beh=C3=BAn wrote: = =20 > > > > > + If present, this property specifies slot power limit in milli= watts. Host > > > > > + drivers can parse this property and use it for programming Ro= ot Port or host > > > > > + bridge, or for composing and sending PCIe Set_Slot_Power_Limi= t messages > > > > > + through the Root Port or host bridge when transitioning PCIe = link from a > > > > > + non-DL_Up Status to a DL_Up Status. =20 > > > > > > > > If your slots are behind a switch, then doesn't this apply to any b= ridge > > > > port? =20 > > > > > > The main issue here is that pci.txt (and also scheme on github) is > > > mixing host bridge and root ports into one node. This new property > > > should be defined at the same place where is supports-clkreq or > > > reset-gpios, as it belongs to them. =20 > >=20 > > Unfortunately that ship has already sailed. So we can split things up, > > but we still have to allow for the existing cases. I'm happy to take > > changes splitting up pci-bus.yaml to 2 or 3 schemas (host bridge, > > root-port, and PCI(e)-PCI(e) bridge?). =20 >=20 > Well, no problem. I just need to know how you want to handle backward > compatibility definitions in YAML. Because it is possible via versioning > (like in JSONSchema-like structures in OpenAPI versioning) or via > deprecated attributes or via defining two schemas (one strict and one > loose)... There are lot of options and I saw all these options in > different projects which use YAML or JSON. >=20 > I did not know about github repository, I always looked at schemas and > definitions only in linux kernel tree and external files which were > mentioned in kernel tree. >=20 > Something I wrote in my RFC email, but I wrote this email patch... > https://lore.kernel.org/linux-pci/20211023144252.z7ou2l2tvm6cvtf7@pali/ New kernel should always work with old device-tree. But does also new device-tree need to work with old kernels? Marek