From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthias Kaehlcke Subject: Re: [PATCH v1] arm64: dts: sdm845: enable tsens thermal zones Date: Wed, 29 Aug 2018 11:12:16 -0700 Message-ID: <20180829181216.GD10879@google.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Return-path: Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org To: Daniel Lezcano Cc: Amit Kucheria , linux-kernel@vger.kernel.org, rnayak@codeaurora.org, linux-arm-msm@vger.kernel.org, bjorn.andersson@linaro.org, andy.gross@linaro.org, dianders@chromium.org, edubezval@gmail.com, David Brown , Rob Herring , Mark Rutland , Catalin Marinas , Will Deacon , linux-soc@vger.kernel.org, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Taniya Das List-Id: devicetree@vger.kernel.org On Wed, Aug 29, 2018 at 11:39:12AM +0200, Daniel Lezcano wrote: > On 18/07/2018 09:49, Amit Kucheria wrote: > > One thermal zone per cpu is defined > > The thermal zones are very close, especially when the CPUs belong to the > same 'cluster'. Very likely the temperature will propagate from one core > to another core, so when one core reaches the trip0, there is good > chance the other cores will be close and cross the trip0 threshold too. > > Having multiple thermal zones, one per CPU, may trigger an interrupts > storm with the passive polling timer delay. > > Does this board have a cooling device per CPU also ? The cpufreq driver is still under development: https://lore.kernel.org/patchwork/patch/966833/ . It currently doesn't register cooling devices, but since CPUs from a 'cluster' use the same cpufreq policy I think there will be one cooling device per 'cluster'.