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=-10.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 10B4AC4363A for ; Thu, 29 Oct 2020 00:30:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B08EC2080C for ; Thu, 29 Oct 2020 00:30:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603931442; bh=WNCPjsZP5pbQSAxe9i9e7kRn/mIXR/PcHMtlIN3Hv6M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=AgfJmNBEKndvqBevDsBssE7fW1GUCZDCvyURCRaM5ibl3Tp41k+WPgUi99Ul62iL4 WR7naOQiOB879T9Z0Xh6w2EcShtVvEZmWBDXGVJ5L5tXGLlJN2hz6qzorpqIGEEzLS 95kb8nwUkKcgJ8SeZabac2yA7EZpb1qbNDqEanI8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388298AbgJ1WdU convert rfc822-to-8bit (ORCPT ); Wed, 28 Oct 2020 18:33:20 -0400 Received: from mail-wr1-f67.google.com ([209.85.221.67]:39519 "EHLO mail-wr1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388260AbgJ1WdT (ORCPT ); Wed, 28 Oct 2020 18:33:19 -0400 Received: by mail-wr1-f67.google.com with SMTP id y12so734421wrp.6; Wed, 28 Oct 2020 15:33:17 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=9qMkACaxgBFGgp14/y74BYPbOoZe+yAscejmhiaaiHI=; b=ToJRGbqWsOr5Tp0L0JDERd4/O/4KaV7gpvowMalTqutn+Bl3QeJ+jhBEUCj+LLX4mr o+9MsOQjVNEg8bjb3mjmtVi8oNoODDyWg1j9QrlRJ/wlYdJpLzm/6h6Ki0R8XkqaIEK5 POxWy7Alag9mk20LJQRniaaJMfEWf2PwxaOEY/mdxe4COvcR0cYfRnp8MQRlQ4+3uBCZ LfIcLmFUmIkhX6k9v7GHsdNn6wrPnskjbaabj1Ag0iJhLq7UB588yhqqWiSDBflG+46g KWygY9/3GJwrxQMuFPFq+BrFgWSCFHCLqzZIfe3Y6Dya6M1AnOwMbM7PQpY9koYA0JOz K4Iw== X-Gm-Message-State: AOAM531s2Bx6kOk3O7V0ebu9O1rxbrtdhouUSSYezSUQvzs5KNCwMIMy 4QPlg2QV2jHE/FZMijIzJhgPQTBjpimaSg== X-Google-Smtp-Source: ABdhPJzFsqaQeMhmEXSs9UrGO3Kmxrx9OhwqKP85Emfcv2bhHljDeQGLFfXI3feKDEwi+e1eh+cN1w== X-Received: by 2002:a50:d987:: with SMTP id w7mr441293edj.113.1603913252990; Wed, 28 Oct 2020 12:27:32 -0700 (PDT) Received: from kozik-lap ([194.230.155.184]) by smtp.googlemail.com with ESMTPSA id y14sm205006edo.69.2020.10.28.12.27.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 28 Oct 2020 12:27:31 -0700 (PDT) Date: Wed, 28 Oct 2020 20:27:29 +0100 From: Krzysztof Kozlowski To: Dmitry Osipenko Cc: Thierry Reding , Jonathan Hunter , Georgi Djakov , Rob Herring , Michael Turquette , Stephen Boyd , Peter De Schrijver , MyungJoo Ham , Kyungmin Park , Chanwoo Choi , Mikko Perttunen , Viresh Kumar , Peter Geis , Nicolas Chauvet , linux-tegra@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org Subject: Re: [PATCH v6 13/52] dt-bindings: memory: tegra124: emc: Document new interconnect property Message-ID: <20201028192729.GA170285@kozik-lap> References: <20201025221735.3062-1-digetx@gmail.com> <20201025221735.3062-14-digetx@gmail.com> <20201027102506.GB17089@kozik-lap> <20201027194833.GE140636@kozik-lap> <0a7aeebf-c5ab-13ea-3927-fa39512afd87@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8BIT In-Reply-To: <0a7aeebf-c5ab-13ea-3927-fa39512afd87@gmail.com> Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Tue, Oct 27, 2020 at 11:16:29PM +0300, Dmitry Osipenko wrote: > 27.10.2020 22:48, Krzysztof Kozlowski пишет: > > On Tue, Oct 27, 2020 at 10:19:28PM +0300, Dmitry Osipenko wrote: > >> 27.10.2020 13:25, Krzysztof Kozlowski пишет: > >>> On Mon, Oct 26, 2020 at 01:16:56AM +0300, Dmitry Osipenko wrote: > >>>> External memory controller is interconnected with memory controller and > >>>> with external memory. Document new interconnect property which turns > >>>> External Memory Controller into interconnect provider. > >>>> > >>>> Signed-off-by: Dmitry Osipenko > >>>> --- > >>>> .../bindings/memory-controllers/nvidia,tegra124-emc.yaml | 7 +++++++ > >>>> 1 file changed, 7 insertions(+) > >>>> > >>>> diff --git a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra124-emc.yaml b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra124-emc.yaml > >>>> index 278549f9e051..ac00832ceac1 100644 > >>>> --- a/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra124-emc.yaml > >>>> +++ b/Documentation/devicetree/bindings/memory-controllers/nvidia,tegra124-emc.yaml > >>>> @@ -29,6 +29,9 @@ properties: > >>>> items: > >>>> - const: emc > >>>> > >>>> + "#interconnect-cells": > >>>> + const: 0 > >>>> + > >>>> nvidia,memory-controller: > >>>> $ref: /schemas/types.yaml#/definitions/phandle > >>>> description: > >>>> @@ -327,6 +330,7 @@ required: > >>>> - clocks > >>>> - clock-names > >>>> - nvidia,memory-controller > >>>> + - "#interconnect-cells" > >>> > >>> Another required property, what about all existing users of this binding? > >> > >> EMC/devfreq drivers check presence of the new properties and ask users > >> to upgrade the DT. The kernel will continue to work fine using older > >> DTBs, but devfreq driver won't load. > > > > If the devfreq was working fine before (with these older DTBs and older > > kernel) then you break the feature. > > > > If devfreq was not working or was not stable enough, then nothing is > > broken so such change is accepted. > > > > Which one is then? > > Definitely the latter. The current devfreq works okay'ish, but we rely > on hardware to recover from temporal FIFO underflows and it's a > user-visible problem which this series addresses. I understand. Fine with me, thanks for explanation. Best regards, Krzysztof