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=-2.2 required=3.0 tests=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 C17C6C433DF for ; Wed, 17 Jun 2020 21:15:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A20FC218AC for ; Wed, 17 Jun 2020 21:15:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726965AbgFQVPL (ORCPT ); Wed, 17 Jun 2020 17:15:11 -0400 Received: from jabberwock.ucw.cz ([46.255.230.98]:50348 "EHLO jabberwock.ucw.cz" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726958AbgFQVPL (ORCPT ); Wed, 17 Jun 2020 17:15:11 -0400 Received: by jabberwock.ucw.cz (Postfix, from userid 1017) id 104E91C0C0D; Wed, 17 Jun 2020 23:15:07 +0200 (CEST) Date: Wed, 17 Jun 2020 23:14:36 +0200 From: Pavel Machek To: Thara Gopinath Cc: rui.zhang@intel.com, ulf.hansson@linaro.org, daniel.lezcano@linaro.org, bjorn.andersson@linaro.org, agross@kernel.org, robh@kernel.org, amit.kucheria@verdurent.com, mark.rutland@arm.com, rjw@rjwysocki.net, linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v6 0/6] Introduce Power domain based warming device driver Message-ID: <20200617211436.GA2078@bug> References: <20200604015317.31389-1-thara.gopinath@linaro.org> <20200616105325.GH1718@bug> <0eb2e140-9c9c-4777-9916-d81eddc793ca@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0eb2e140-9c9c-4777-9916-d81eddc793ca@linaro.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-arm-msm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-arm-msm@vger.kernel.org Hi! > >>falls below certain threshold. These power domains can be considered as > >>thermal warming devices. (opposite of thermal cooling devices). > > > >Would you explain when this is needed? > > > >I'd normally expect "too low" temperature to be a problem during power-on, but at > >that time Linux is not running so it can not provide the heating... > Hi Pavel, > > This is more in the scenario if the system in on and temperature is dipping > (I have been told in colder climates). Idea is to turn on resources so as to > prevent further dipping of temperature if possible. I guess even that makes sense... But, out of curiosity, do you know which kind of device is that and in what kind of environment? I mean, theoretically it may make sense on a cellphone, but... I guess you have some fun device and would like to know what it is :-). Hmm. And we can make this quite generic. while (too_cold()) barrier(); Wasting power is really easy :-). Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html