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=-2.4 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 D1250C47404 for ; Wed, 9 Oct 2019 12:54:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AABEC20B7C for ; Wed, 9 Oct 2019 12:54:40 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="Ieth1LzW" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731216AbfJIMyj (ORCPT ); Wed, 9 Oct 2019 08:54:39 -0400 Received: from mail-qt1-f195.google.com ([209.85.160.195]:36872 "EHLO mail-qt1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731214AbfJIMyj (ORCPT ); Wed, 9 Oct 2019 08:54:39 -0400 Received: by mail-qt1-f195.google.com with SMTP id l51so2956127qtc.4 for ; Wed, 09 Oct 2019 05:54:39 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=subject:to:references:cc:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding; bh=TgY7kPmBZqnecD8fmdALLpGAi+Y1sBS44TN0W3OZTbI=; b=Ieth1LzWB3tqDdxRYS6TrTDImdY44X93i3yUuyswKh9NjwTJ9MG4I2p3ASCGRBbhIi EN685xkM080/OSbNL3HVipQhMTiUC3wCskwGs71Fi0G583KGpAhgDjb9VZTSwNOizajq KjMDn74QgrW5rjxwCxpxgHrztK5XKLYGw7Ptb6Dzw2Um68uQEEtb9QD58DgmCL+djw5x hvj6SPb+jQ8H91BafRWYx9bXKeCGoUZ3pYmo9zaWEqj9Hbxyx5PkknrLQpIrt+b6pPv2 UWqyEnjMQk6gtxIgsg+zv6Xm7CfObViLTHWCh+F8QEAs8uzXv+iWzUnHp4NYkK8A+eno 2GbA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:references:cc:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding; bh=TgY7kPmBZqnecD8fmdALLpGAi+Y1sBS44TN0W3OZTbI=; b=BuzsJW207BFIV7IVxWJMLwZ//nCD5W+QVH8lmL2s8gsErHIsK4fpP37H2z14F5s88b Ru3IHizUztwLAV1swYLJ3PHQ8CHeV9oXmb0MrWSzV9/3R8BZULFgPjZpB7LZObSdlyLb mQzj1LeUml/v93CmwgLWUs7OoR1a5CZFHNtsuD3NLxiLqf7vsIaAKUm7UVmhiGw4tHFx HYvteLwdAEi5Sakm15aK9Aq6Y25n3NTQYIxgZq3at9BTifMIY1G5gi5NXf8UZb44Ck6+ ulWYb5Wt6HNIO31omV185gBYq/gNzEKH9hRhnqWVYw7wqGx71PMNQQAJqplCq04gKGIZ Wr2A== X-Gm-Message-State: APjAAAWVuxiUlkUiWlZH0rXumkQTHE6DIsH+dgWmLM/VfcATe1KWmy90 47qH1iuyixmgzEE+/xqjf9gJHg== X-Google-Smtp-Source: APXvYqxDRTRnNCFB3xzy90ZREa6zqiTGq9G4A+t6sp3p4WDaJF1dHGjJKNb5yoJjpKhBQP6sEqhRHA== X-Received: by 2002:a0c:ef85:: with SMTP id w5mr3460733qvr.159.1570625678531; Wed, 09 Oct 2019 05:54:38 -0700 (PDT) Received: from [192.168.1.169] (pool-71-255-246-27.washdc.fios.verizon.net. [71.255.246.27]) by smtp.gmail.com with ESMTPSA id c201sm890854qke.128.2019.10.09.05.54.37 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 09 Oct 2019 05:54:37 -0700 (PDT) Subject: Re: [PATCH 1/4] dt-bindings: thermal: Introduce monitor-falling parameter to thermal trip point binding To: Rob Herring References: <1568859503-19725-1-git-send-email-thara.gopinath@linaro.org> <1568859503-19725-2-git-send-email-thara.gopinath@linaro.org> <5d93ce86.1c69fb81.70b0d.ba56@mx.google.com> Cc: rui.zhang@intel.com, edubezval@gmail.com, daniel.lezcano@linaro.org, vincent.guittot@linaro.org, bjorn.andersson@linaro.org, amit.kucheria@verdurent.com, mark.rutland@arm.com, linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org From: Thara Gopinath Message-ID: <5D9DD88C.7090804@linaro.org> Date: Wed, 9 Oct 2019 08:54:36 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.5.1 MIME-Version: 1.0 In-Reply-To: <5d93ce86.1c69fb81.70b0d.ba56@mx.google.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org Hi Rob, Thanks for the review. On 10/01/2019 06:09 PM, Rob Herring wrote: > On Wed, Sep 18, 2019 at 10:18:20PM -0400, Thara Gopinath wrote: >> Introduce a new binding parameter to thermal trip point description >> to indicate whether the temperature level specified by the trip point >> is monitored for a rise or fall in temperature. > > What if it is both? > > When do you need this? Seems like you'd always want to monitor both > directions to undo any action done on rising temp. Unless you want a > hysteresis, but this doesn't seem like the best way to implement that. > The thermal framework is designed in such a manner that I cannot think of a use case for both. The framework takes care of removing the warming/cooling action when the trip point is crossed in the opposite direction. It only needs an indication on when to start implementing the action. For eg. When the temperature crosses/increases above 90 degree, the framework will start the cooling action and will continue monitoring till the temperature falls below 90 and the cooling action is removed. Vice versa when the temperature decreases below say 5 degree, the framework should initiate the warming action and monitor till the temperature rises above and remove the warming action. So the trip point is really an indication of the temperature crossing a threshold in the specified direction. Now this parameter is needed to indicate whether the thermal framework has to start implementing the warming/cooling action when the temperature rises above the trip point or falls below the trip point. Till now the framework was always assuming that the cooling action had to be implemented when temperature rises above the trip point. -- Warm Regards Thara