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 EFA58C433EF for ; Fri, 12 Nov 2021 17:12:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C420560FE3 for ; Fri, 12 Nov 2021 17:12:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232030AbhKLRPn (ORCPT ); Fri, 12 Nov 2021 12:15:43 -0500 Received: from mail.kernel.org ([198.145.29.99]:32782 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230051AbhKLRPn (ORCPT ); Fri, 12 Nov 2021 12:15:43 -0500 Received: by mail.kernel.org (Postfix) with ESMTPSA id 72E4160E98; Fri, 12 Nov 2021 17:12:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1636737172; bh=XAhjClpN8pzzmnkn/qvi49BFy5bv+twtH7DITQsG29E=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=MKQ6rCI1T8EYV/wI2GLXrZAWpaJSuvOMOVlFuslsGB8fT7+rvC1OGkLS6vCgdws89 baw5OZrJ+zPvSqhkBJbo7iu5J6KL4gmUgouAFcGperIU9wsN5HBceR0WoXMytf99eU 1oKw1S89WI30hg/hgqQodYUd65roTVRk8JAtnc5/dO20QyUuR1wTf4pBcsvHAAWCJj qTjTrmML5sX4xISnqZzYQG33vU3FO9Q/nBFUrvfGrAD3IZEcfwWmBfUzL99PTTc5uK r8X8BKWFFpSv+RVXUBvpiX4cAKCbjvhfaYmCWNK2P68igeWrBYLFJ67kxg/0Zrc8jQ N2jdh9RtKwPWw== Received: by pali.im (Postfix) id 1C2B679D; Fri, 12 Nov 2021 18:12:50 +0100 (CET) Date: Fri, 12 Nov 2021 18:12:49 +0100 From: Pali =?utf-8?B?Um9ow6Fy?= To: Rob Herring Cc: Marek =?utf-8?B?QmVow7pu?= , 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: <20211112171249.46xmj5zo3svm4qn2@pali> References: <20211031150706.27873-1-kabel@kernel.org> <20211112153208.s4nuckz7js4fipce@pali> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: NeoMutt/20180716 Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Friday 12 November 2021 10:30:01 Rob Herring wrote: > On Fri, Nov 12, 2021 at 9:32 AM Pali Rohár wrote: > > > > On Friday 12 November 2021 09:25:20 Rob Herring wrote: > > > On Sun, Oct 31, 2021 at 04:07:05PM +0100, Marek Behún wrote: > > > > + If present, this property specifies slot power limit in milliwatts. Host > > > > + drivers can parse this property and use it for programming Root Port or host > > > > + bridge, or for composing and sending PCIe Set_Slot_Power_Limit messages > > > > + through the Root Port or host bridge when transitioning PCIe link from a > > > > + non-DL_Up Status to a DL_Up Status. > > > > > > If your slots are behind a switch, then doesn't this apply to any bridge > > > port? > > > > 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. > > 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?). 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. 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. Something I wrote in my RFC email, but I wrote this email patch... https://lore.kernel.org/linux-pci/20211023144252.z7ou2l2tvm6cvtf7@pali/ > > And you are right, that this new property should be defined only for > > root ports and downstream ports of switch.