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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no 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 A77FFC5517A for ; Thu, 5 Nov 2020 10:35:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4B5C122210 for ; Thu, 5 Nov 2020 10:35:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="BiAiD4e1" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729772AbgKEKfF (ORCPT ); Thu, 5 Nov 2020 05:35:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36078 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728999AbgKEKfE (ORCPT ); Thu, 5 Nov 2020 05:35:04 -0500 Received: from mail-vs1-xe44.google.com (mail-vs1-xe44.google.com [IPv6:2607:f8b0:4864:20::e44]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BE2D3C0613D6 for ; Thu, 5 Nov 2020 02:35:03 -0800 (PST) Received: by mail-vs1-xe44.google.com with SMTP id r14so475308vsa.13 for ; Thu, 05 Nov 2020 02:35:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=ZdAvLjoOXomWCs8t6TmIL4j/I5mepz3FWTuHztdBTlc=; b=BiAiD4e1h7itpTTBhs3DR4K8CfgZymL8qj1e7tZjDyvL22TAbVaJrB6OdCOJ9dCgt8 uMo1WI+cg7RQpxF0bBlJEyznK83VkivtEouWpjXE0uDzswIn9ngEEIWZkBVtGoJKPI5a 3gYONlFV9O8ISMzu91uUEboniTdwBNNIgS1GVf+ZVCHpgeExfkJ3HUKHZ4pHVFwQwMtx 5vGFFB38gJyFP7FBlRczIoGJ/8EUs8e6gc59Rm7O/sKD+Kj4+eFQl2/7R5M52mOjdRQY 23FqbRx5TWg7iDot8DaIDKVfEKsFUNqqGSEPkpoltdKL/CwkFxGm9pZGSMzsaqx/PW9N dskg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=ZdAvLjoOXomWCs8t6TmIL4j/I5mepz3FWTuHztdBTlc=; b=ih8oHe30vb5xW8rqK/8GiTY1THYdSQtMjETRw1oBuN0AhG6vPiqGalBMrHZmGTzUes XwaY5tIc+PADRPTm13Mpf732Ms4of6UeZ17GHGbjf/IGvnEv98h9viMNKQ6iFU/X43ZK wSCffcrV8e1jVwarC/ZR/Il3+XpcqoVX/n+YLAO5B5OPBDyaz9HSfeWKRKrGYVo9eFuv 7yiPLJ/qmY/lnLkVf205+ImGXF8M9pIrVUmfL1bYAEobc/uMmmwNBm+4KlkIOqmwEkZk pdCSWmJx51NVS89FqTaiVZ0TZqD1Gi4wcXZXlqAq8lLwPKUauyfakse7oYygydw45G8A coDg== X-Gm-Message-State: AOAM531yfyUG1l4hI+STx3AneQLN7GB+s/QE+NRY/u3hn8mZy4guSb2D UO8+aDjx75UrmKYHuxc+WC3TNBmvhsNi/gT+n4mWwQ== X-Google-Smtp-Source: ABdhPJxVfapO8HtgRahAnJ4wz7s9HOgbHIAKW7gtu7MmcNt2t4MXd/COFLbP0begvsat+FQbNQGgY8Hv6gEHSKm9IGw= X-Received: by 2002:a67:f417:: with SMTP id p23mr725992vsn.42.1604572502741; Thu, 05 Nov 2020 02:35:02 -0800 (PST) MIME-Version: 1.0 References: <20201104234427.26477-1-digetx@gmail.com> <20201105100603.skrirm7uke4s2xyl@vireshk-i7> In-Reply-To: <20201105100603.skrirm7uke4s2xyl@vireshk-i7> From: Ulf Hansson Date: Thu, 5 Nov 2020 11:34:26 +0100 Message-ID: Subject: Re: [PATCH v1 00/30] Introduce core voltage scaling for NVIDIA Tegra20/30 SoCs To: Viresh Kumar Cc: Dmitry Osipenko , Thierry Reding , Jonathan Hunter , Alan Stern , Peter Chen , Mark Brown , Liam Girdwood , Adrian Hunter , Krzysztof Kozlowski , Greg Kroah-Hartman , Lee Jones , =?UTF-8?Q?Uwe_Kleine=2DK=C3=B6nig?= , Mauro Carvalho Chehab , Rob Herring , Marek Szyprowski , Peter Geis , Nicolas Chauvet , linux-samsung-soc , driverdevel , Linux USB List , linux-pwm@vger.kernel.org, "linux-mmc@vger.kernel.org" , Linux Kernel Mailing List , DTML , dri-devel , Linux Media Mailing List , linux-tegra Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org On Thu, 5 Nov 2020 at 11:06, Viresh Kumar wrote: > > On 05-11-20, 10:45, Ulf Hansson wrote: > > + Viresh > > Thanks Ulf. I found a bug in OPP core because you cc'd me here :) Happy to help. :-) > > > On Thu, 5 Nov 2020 at 00:44, Dmitry Osipenko wrote: > > I need some more time to review this, but just a quick check found a > > few potential issues... > > > > The "core-supply", that you specify as a regulator for each > > controller's device node, is not the way we describe power domains. > > Maybe I misunderstood your comment here, but there are two ways of > scaling the voltage of a device depending on if it is a regulator (and > can be modeled as one in the kernel) or a power domain. I am not objecting about scaling the voltage through a regulator, that's fine to me. However, encoding a power domain as a regulator (even if it may seem like a regulator) isn't. Well, unless Mark Brown has changed his mind about this. In this case, it seems like the regulator supply belongs in the description of the power domain provider. > > In case of Qcom earlier (when we added the performance-state stuff), > the eventual hardware was out of kernel's control and we didn't wanted > (allowed) to model it as a virtual regulator just to pass the votes to > the RPM. And so we did what we did. > > But if the hardware (where the voltage is required to be changed) is > indeed a regulator and is modeled as one, then what Dmitry has done > looks okay. i.e. add a supply in the device's node and microvolt > property in the DT entries. I guess I haven't paid enough attention how power domain regulators are being described then. I was under the impression that the CPUfreq case was a bit specific - and we had legacy bindings to stick with. Can you point me to some other existing examples of where power domain regulators are specified as a regulator in each device's node? Kind regards Uffe