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=-1.0 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 E5329C43219 for ; Thu, 2 May 2019 01:39:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B179D2085A for ; Thu, 2 May 2019 01:39:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="dyQQJ5Q7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726207AbfEBBjt (ORCPT ); Wed, 1 May 2019 21:39:49 -0400 Received: from mail-lf1-f65.google.com ([209.85.167.65]:44585 "EHLO mail-lf1-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726139AbfEBBjt (ORCPT ); Wed, 1 May 2019 21:39:49 -0400 Received: by mail-lf1-f65.google.com with SMTP id h18so605024lfj.11; Wed, 01 May 2019 18:39:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:from:to:cc:references:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=EKKVG5737NrpS/LA8GajQUyTQUsuWWyVh2aWGz7aFb0=; b=dyQQJ5Q7assiIarPt+M23smzYoQ+W/DKcGA0vmYLZIfEoQWhvipprsIhRiXZUyQ369 k+5U7IQhHBUYDY5u/YQAIUgKkMS4c5eNjHC1mj4LcPiVetf3kT0gGe2XFWPihblQ0/Kk 7pR0UcXnP1QuuuZ7NThrQXM2nxEe/gjwPvbuX6aVZ+F+NP3QAwd07XNkpcRqDQxEPPZn C3ka8R5jzCEaqhktwz6vDSPSZTiCcjycDJKAJ9C9/lmsu/g6KiMOMrmAI4lOwIZz52Mx befF8feppzk489cP7w/7qPRivEbjZqYRKXmyh879zZ1PZ08zJuvFu/mQoMOO+9z2IUwS sF0A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:references:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=EKKVG5737NrpS/LA8GajQUyTQUsuWWyVh2aWGz7aFb0=; b=XX5IQz3twV9Hj/gYiilUDpYDEG/IXUdYJGvRXVHaN6B6gdCeFg80GSw7vZSCFdH/3U yreb1oGobl4rsBQL3XrQo/bQm9sSSHmk0S0Z8iC6BynoDaNsTygHJ5GXuKoWKDp8Y2Hz O6mUkhl9w3nW+eLG1B3OGQnJC/rnUdpHcek80Ym51DR4upMYfco6Famtv/N+qbFHxkcr 6xLSMjoYw/7Bp7PsmLnNw6rJtdIPTot84bG6xZy6rYCHHL8NfLzH/COEVdWuZf9dHmLu giK/LgctDcdmSqHVbSqGLF890pz2P1Hzi65BtS9iDjx8jREkTaacfDk79OUou6k0dIg+ KgTg== X-Gm-Message-State: APjAAAW5SLG4PWvu5AqANLbzzMv4s1BlRABMYTfVtW3G/UVIDZWRWg2X qMT3ZiFbQzN0KlZWoXsqL+BY+4Lh X-Google-Smtp-Source: APXvYqx6rRBsJnpEx8oZbstFl0E7VH7dKBWlM3VvuClpu8+yxBlcocwTumm8qTINcHxH1fl5re0HcA== X-Received: by 2002:ac2:538a:: with SMTP id g10mr484312lfh.141.1556761186463; Wed, 01 May 2019 18:39:46 -0700 (PDT) Received: from [192.168.2.145] (ppp94-29-35-107.pppoe.spdop.ru. [94.29.35.107]) by smtp.googlemail.com with ESMTPSA id f12sm5299832lfk.6.2019.05.01.18.39.45 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 01 May 2019 18:39:45 -0700 (PDT) Subject: Re: [PATCH v2 2/4] dt-bindings: memory: Add binding for NVIDIA Tegra30 External Memory Controller From: Dmitry Osipenko To: Rob Herring Cc: Mark Rutland , Peter De Schrijver , Prashant Gaikwad , Michael Turquette , Stephen Boyd , Thierry Reding , Jonathan Hunter , Joseph Lo , devicetree@vger.kernel.org, linux-clk , linux-tegra@vger.kernel.org, "linux-kernel@vger.kernel.org" References: <20190414202009.31268-1-digetx@gmail.com> <20190414202009.31268-3-digetx@gmail.com> <20190429220542.GA17924@bogus> <137c766e-66f6-828a-5c3b-f526d66d37bd@gmail.com> <27d24f4e-cf4c-b2d1-140a-5dcef021fa40@gmail.com> Message-ID: <7b6867f4-54b2-f3b5-2b4e-87ea3000fa44@gmail.com> Date: Thu, 2 May 2019 04:39:44 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <27d24f4e-cf4c-b2d1-140a-5dcef021fa40@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-clk-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org 02.05.2019 3:52, Dmitry Osipenko пишет: > 02.05.2019 3:17, Rob Herring пишет: >> On Wed, May 1, 2019 at 7:06 PM Dmitry Osipenko wrote: >>> >>> 30.04.2019 1:05, Rob Herring пишет: >>>> On Sun, Apr 14, 2019 at 11:20:07PM +0300, Dmitry Osipenko wrote: >>>>> Add device-tree binding for NVIDIA Tegra30 External Memory Controller. >>>>> The binding is based on the Tegra124 EMC binding since hardware is >>>>> similar, although there are couple significant differences. >>>> >>>> My comments on Tegra124 binding apply here. >>> >>> The common timing definition doesn't fully match the definition that is >>> used by Tegra's Memory Controller, thus the DQS (data strobe) timing >>> parameter is comprised of multiple sub-parameters that describe how to >>> generate the strobe in hardware. There are also more additional >>> parameters that are specific to Tegra and they are individually >>> characterized for each memory model and clock rate. Hence the common >>> timing definition isn't usable. >> >> I don't understand. Every PC in the world can work with any DIMM >> (within a given generation) just with SPD data. Why is that not >> sufficient here? > > Because this is not a standard PC, but a custom embedded hardware that > is simpler and also doesn't fully follow the standards in some cases. Even if there is a way to derive at least some of required parameters from the common timing, I don't have information about how to do it and there is pretty much no chance to get it into public. Rob, please let me know if you're okay with this binding.