From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sudeep Holla Subject: Re: [PATCH] thermal: of: Allow selection of thermal governor in DT Date: Tue, 6 Mar 2018 12:32:08 +0000 Message-ID: <6d5aeab8-aafe-fa3b-585e-953a34864e7d@arm.com> References: <3b80853abb45a9e067cf7a16754b07bb67712457.1520274879.git.amit.kucheria@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <3b80853abb45a9e067cf7a16754b07bb67712457.1520274879.git.amit.kucheria@linaro.org> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: Ram Chandrasekar Cc: Amit Kucheria , devicetree@vger.kernel.org, Sudeep Holla , ilina@codeaurora.org, Zhang Rui , Eduardo Valentin , Rob Herring , Mark Rutland , linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: linux-pm@vger.kernel.org On 05/03/18 18:36, Amit Kucheria wrote: > From: Ram Chandrasekar > > There is currently no way for the governor to be selected for each thermal > zone in devicetree. How is that any different from cpufreq, cpuidle or devfreq subsystems ? > This results in the default governor being used for all > thermal zones even though no such restriction exists in the core code. > What restrictions ? > Add support for specifying the thermal governor to be used for a thermal > zone in the devicetree. Then what prevents us from doing the same for other subsystems with so called /inefficient default/ governors ? > The devicetree config should specify the governor > name as a string that matches any available governors. If not specified, we > maintain the current behaviour of using the default governor. If one is specified, can the user change it from sysfs ? If yes, then why do we need this binding at all ? If no, we are basically restricting, then what would happen if the DT was shipped with wrong governor specified because the firmware author didn't know about any other governor ? IMO, having this in DT is bad idea as it may cause more issues than gain. We already have sysfs support like other PM subsystems and userspace can deal with it. -- Regards, Sudeep