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=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 AF4E6C4CEC7 for ; Thu, 12 Sep 2019 18:52:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7CD052084D for ; Thu, 12 Sep 2019 18:52:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="NgcPydo2" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727491AbfILSwU (ORCPT ); Thu, 12 Sep 2019 14:52:20 -0400 Received: from mail-io1-f68.google.com ([209.85.166.68]:46020 "EHLO mail-io1-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727448AbfILSwU (ORCPT ); Thu, 12 Sep 2019 14:52:20 -0400 Received: by mail-io1-f68.google.com with SMTP id f12so57234298iog.12; Thu, 12 Sep 2019 11:52:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=3M0DBEXT0zXnU4neN83IHPC2RjV0S6rYgjI5uWAT12I=; b=NgcPydo2tnBFyQ8PRGmVKYOa/CjQWPcH+rPzJRym1Kpcnvg3TXtgXj3tQSFgtOn/Du v05IkAQjclxPsKgqnGm+5iLzfl8JkJOH6nwW7zkxMWF/psBTsuhIGxTuHnakVp2fjI3d u/cGqgSTa/eUC7cByKpZTl+XSFz2SJHJ6XEyk9H/F5UDNJRvfNoNeznLDWZ3GvovqOi5 S0m4LwYNSWvMu3CKm3oAn793ElqUZxImpyHq67UPNFEP1yoJ7RQzOkLCdZPOlZp+6BLN bA9hqoAmjnhzopAq8fzWR6BXYu8QEWI/ZxcR8/mGTpp4jAuhKXXlHRp5OQPMcw4v8KSC 77BQ== 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:content-transfer-encoding; bh=3M0DBEXT0zXnU4neN83IHPC2RjV0S6rYgjI5uWAT12I=; b=H4HsxlUvogynBiTPGqIoNWDTIn9dHV4/SXfJsMpxX1MVqz6jJB45zIPoNXc0oD+XQS JyfdT7nhaCep7/np2gJZuvbKMqH2pUmVMoID8XUZ4QEO6HlS9RbKRckg2cELHBDXBRN2 7CFUUS9P0ce+VN4UJ8z8D5FhducwzsesDg5tgxmN1hzzMuw0JAe6igxa4nBF0JDj6FB0 diao5N0jGNeKICr7rMFLINz0PLry9tjGAlWcBbnFuDMLgSrCJrkIMG0RsH8XHimBt9IX 89xITuqXeslAVrxbir3u7EsjVH2oiSU31FUnpH5o+43Bip0yNsTRAeGO9sYH+NHoKRql xsJQ== X-Gm-Message-State: APjAAAUASSWKNtZcQnQMY1PY2Stjqepgx3x9Rtju38n0XuWKLNwqTjjq j2V092/Pve6F0aCHN1RILDe11lX5ONVUUpZu8IQ= X-Google-Smtp-Source: APXvYqwwVFw6gGI305ZlvQKdfT14pyiI8jfNuGBQTI0oraMAxLIkKvfVTtMjr22umZkSUMCYU7LMnot5boJy+3kYV0o= X-Received: by 2002:a5e:dc47:: with SMTP id s7mr4463354iop.228.1568314338240; Thu, 12 Sep 2019 11:52:18 -0700 (PDT) MIME-Version: 1.0 References: <0C1EF64E-B33C-4BFA-A7D3-471DD1B9EE86@goldelico.com> <515048DE-138D-4400-8168-F2B7D61F1005@goldelico.com> <7B3D1D77-3E8C-444F-90B9-6DF2641178B8@goldelico.com> <87420DBD-770F-4C32-9499-A3AEA5876E8A@goldelico.com> <20190909163236.GP52127@atomide.com> <3663B13C-1AAB-4BE3-8CAD-F821B70393FA@goldelico.com> <56482888-DBD3-4658-8DB9-FB57653B5AA8@goldelico.com> <285FED38-2B2B-4813-9FD2-396C53E9B1B2@goldelico.com> <65A23326-70B4-46E3-992D-74256B056900@goldelico.com> In-Reply-To: From: Adam Ford Date: Thu, 12 Sep 2019 13:52:06 -0500 Message-ID: Subject: Re: [Letux-kernel] [RFC PATCH 0/3] Enable 1GHz support on omap36xx To: "H. Nikolaus Schaller" Cc: Nishanth Menon , Linux-OMAP , Tony Lindgren , Linux Kernel Mailing List , =?UTF-8?Q?Andr=C3=A9_Roth?= , Discussions about the Letux Kernel Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Sep 12, 2019 at 8:58 AM Adam Ford wrote: > > On Wed, Sep 11, 2019 at 12:49 PM Adam Ford wrote: > > > > On Wed, Sep 11, 2019 at 12:43 PM H. Nikolaus Schaller wrote: > > > > > > Hi Adam, > > > > > > > Am 11.09.2019 um 18:01 schrieb H. Nikolaus Schaller : > > > > > > > >> > > > >> Am 11.09.2019 um 17:56 schrieb Adam Ford : > > > >> > > > >>> There are some subtleties for testing. > > > >>> > > > >>> * I have added turbo-mode; to OPP6 / OPP1G > > > >>> * which means they are available but not used by the ondemand gov= enor > > > >>> * to enable them one has to echo 1 >/sys/devices/system/cpu/cpufr= eq/boost > > > >> > > > >> Will that be documented somewhere? If not, can we put a comment in= the > > > >> device tree so people know how to enable it? > > > > > > > > It seems to be pretty standard on i86 systems if you google for "tu= rbo mode". > > > > I have added it to the commit message which adds the vbb regulator. > > > > > > And, I am not sure if DT maintainers will accept comments about the > > > Linux /sys implementation in device tree files or bindings. Those > > > should be independent of Linux. > > > > OK. > > > > > > Basically the turbo-mode property is a hint to the OPP system (which > > > may or may not use of it). > > > > > > So I think it is indeed better to have it in the commit message and > > > not the code. > > > > That makes sense. > > > > > > > > One more thought: as long as we do not have junction temperature moni= toring > > > we should keep it off by default... We may even remove the turbo-mode > > > designator if we have the 90=C2=B0C limit and smart reflex working. > > I found some info on the thermal framework [1]. It seems to show that > we can put placeholders in the device tree to help facilitate this. > > An excerpt from [1] shows: > Cooling devices provide control on power dissipation. > There are essentially two ways to provide control on power dissipati= on. > First is by means of regulating device performance, which is > known as passive cooling (DVFS). > ... [snip stuff about cooling fans] > > It also shows there are ways to link the cpu node to the cooling info. > Since it shows DVFS can be used to regulate temperature, it seems like > the hooks might already be in place > > [1] - https://blog.linuxplumbersconf.org/2015/ocw//system/presentations/2= 613/original/thermal-framework-status-no-transitioning.pdf > > The downside is that the OMAP thermal sensor is unreliable. I submitted an RFC for thermal throttling. I am not sure if I did it right, and I don't have a good way to test it. adam > > > > We're almost there! > > > > adam > > > > > > BR, > > > Nikolaus > > >