From patchwork Thu Sep 17 03:22:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Thara Gopinath X-Patchwork-Id: 250201 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=-6.8 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,USER_AGENT_GIT 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 A794EC2BBD1 for ; Thu, 17 Sep 2020 03:29:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6EBD02080C for ; Thu, 17 Sep 2020 03:29:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=linaro.org header.i=@linaro.org header.b="ZoAZr1W5" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726129AbgIQD2C (ORCPT ); Wed, 16 Sep 2020 23:28:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41018 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726097AbgIQD2B (ORCPT ); Wed, 16 Sep 2020 23:28:01 -0400 Received: from mail-qk1-x742.google.com (mail-qk1-x742.google.com [IPv6:2607:f8b0:4864:20::742]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 23589C06174A for ; Wed, 16 Sep 2020 20:22:28 -0700 (PDT) Received: by mail-qk1-x742.google.com with SMTP id o16so835428qkj.10 for ; Wed, 16 Sep 2020 20:22:28 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=KcbOfWlEFuul00HQqd8oilYbvxROka4ZC4SJrI4joOI=; b=ZoAZr1W5Oy5cf66eKQDQmN5f8ior/qPaBYuhUSTkzttNy0/O9TEdGWW4csN2pa49hh id6Fmyh9QZCKAH0LJv0YPxZGf8vB/Itcyb+O/nYPdnbtGUhdBnRYcDkntbur9LKRXaQc wj53IAzDyNAzQFKT2B9CkUV0rX5xEsCfMERavdq1QiHUHPoIZu5B+99HQgYDEnTp1Ykh 7zKTNEG9VaH025rt4wOluXioXoDuWzGUh4DNamII+pIl2TcaS9XZyfQhFEsqaPIN/9aA CqwwYu7Z6KiZaYLWHss70WCO1qEl1UGGACL5OWYmfdGeRSCEWjQoTbfbs1s3MM3DSVuC z4tQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=KcbOfWlEFuul00HQqd8oilYbvxROka4ZC4SJrI4joOI=; b=GnNKPDE3aAsEk12dyIhuahAtfa/fNCuZ6SAZAtTFpywDhpjR5EMeyHm6lpTOD8fFpr 2x909ffTd5KptQgxkHxMNGf3EJcQss2ra56EqIn4pG4moMc8PxoEK4xEr7AworeVhXfn a3Gj1/x4CskhymLKwq7CbwTtdfN/AZrlkHB5SEenJtcFHQXsitJU7v4XpCr09FLrWwaY K2BxKYT0yB6GquH28mozUFYo02L2Vg79D1ZiPaUu+L2biQXs2LFstaXV9eHill3HWjQW UAPA1jj9FxAVEjx9eLvSJDgp6EsqSqUkvbcrOpUAzh4ll52RBCHP3tRE3PxXz4qnsgxl xOFQ== X-Gm-Message-State: AOAM530qcD7wlB048+cUW54N+vJ6p5mKMOHchSJb5dXqt8oIZpuqVuOW An+u5TRrMyLJUlNOCJ7rxyCagg== X-Google-Smtp-Source: ABdhPJycdE9iUoUS8L8EAQ9dflosqsZ4aHX4wg/fxy61biNVVViV9GA9A6GsEun9aHQ6DekgpsepBg== X-Received: by 2002:a05:620a:2082:: with SMTP id e2mr25150130qka.421.1600312947892; Wed, 16 Sep 2020 20:22:27 -0700 (PDT) Received: from pop-os.fios-router.home (pool-71-163-245-5.washdc.fios.verizon.net. [71.163.245.5]) by smtp.googlemail.com with ESMTPSA id g45sm21370801qtb.60.2020.09.16.20.22.27 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 16 Sep 2020 20:22:27 -0700 (PDT) From: Thara Gopinath To: rui.zhang@intel.com, daniel.lezcano@linaro.org, robh+dt@kernel.org, agross@kernel.org, bjorn.andersson@linaro.org Cc: linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, lukasz.luba@arm.com, amitk@kernel.org Subject: [PATCH RFC 0/8] Introduce warming in thermal framework Date: Wed, 16 Sep 2020 23:22:18 -0400 Message-Id: <20200917032226.820371-1-thara.gopinath@linaro.org> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Thermal framework today supports monitoring for rising temperatures and subsequently initiating cooling action in case of a thermal trip point being crossed. There are scenarios where a SoC need warming mitigating action to be activated if the temperature falls below a cetain permissible limit. Since warming action can be considered mirror opposite of cooling action, most of the thermal framework can be re-used to achieve this. The key assumption in this patch series is that a device can act either as a warming device or a cooling device and not as both. In order to support warming three extensions are needed in the thermal framework. 1. Indication that a trip point is being monitored for falling temperature and not rising temperature. We discussed two different ways to achieve this during LPC. First option is to introduce a new trip type to indicate that a trip is a cold trip(THERMAL_TRIP_COLD). The second option is to introduce a new property for trip point that will indicate whether a trip point is being monitored for rising temperature or falling temperature. The patch series(patches 1-4) chooses the second approach since it allows trip points of any type to be monitored for rising or falling temperature.Also this was the preferred approach when discussed during LPC. The approach that introduces a new cold trip type was posted on the list earlier as a RFC and can be found at [1]. 2. Extend the exisitng governors to handle monitoring of falling temperature. The patch series(patches 5 & 6) extends the step wise governor to monitor the falling temperature.Other governors return doing nothing if the trip point they are being called for is being monitored for falling temperature. The governors' mitigate function is called "throttle" in the thermal framework and with this patch series it is a misnomer as the function is called for both throttling and warming up. Ideally "throttle" should be renamed to "mitigate" to improve readability of code. The renaming is not part of this series. 3. Finally, the cooling device framework itself can be reused for a warming device. As stated before a device can act either as a warming device or a cooling device and not as both. With this the cooling state in the framework can be considered as mitigating state with 0 as the state with no thermal mitigation and higher the number higher the thermal mitigation. Again what affects the code readability and comprehension is the term "cooling" which is a misnomer here. Ideally the term "cooling" should be renamed to "mitigating" and hence thermal_cooling_device will become thermal_mitgating_device. The renaming is not part of the patch series as even though the renaming is a simple search-replace, it will change a lot of files. The patch series(patches 7 & 8) instead introduces a minimal set of _warming_device_ apis to register and unregister warming devices which internally is identical to the _cooling_device_ counterpart. 1. https://lkml.org/lkml/2020/7/10/639 Thara Gopinath (8): dt-bindings: thermal: Introduce monitor-falling parameter to thermal trip point binding thermal: Introduce new property monitor_type for trip point. thermal: thermal_of: Extend thermal dt driver to support bi-directional monitoring of a thermal trip point. thermal:core:Add genetlink notifications for monitoring falling temperature thermal: gov_step_wise: Extend thermal step-wise governor to monitor falling temperature. thermal: Modify thermal governors to do nothing for trip points being monitored for falling temperature thermal:core: Add is_warming_dev and supporting warming device api's to the cooling dev framework. soc:qcom:qcom_aoss: Change cooling_device_register to warming_device_register .../bindings/thermal/thermal-zones.yaml | 7 ++ drivers/soc/qcom/qcom_aoss.c | 6 +- drivers/thermal/gov_bang_bang.c | 12 ++ drivers/thermal/gov_fair_share.c | 12 ++ drivers/thermal/gov_power_allocator.c | 12 ++ drivers/thermal/gov_step_wise.c | 62 +++++++--- drivers/thermal/thermal_core.c | 113 +++++++++++++++--- drivers/thermal/thermal_core.h | 2 + drivers/thermal/thermal_of.c | 22 ++++ include/linux/thermal.h | 9 ++ include/uapi/linux/thermal.h | 5 + 11 files changed, 226 insertions(+), 36 deletions(-)