Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <a5730ce7-a24c-0738-e76f-e06d56601408@linaro.org>
Date:   Tue, 22 Feb 2022 23:10:51 +0100
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.5.0
Subject: Re: [PATCH 1/2] thermal: cooling: Check Energy Model type in
 cpufreq_cooling and devfreq_cooling
Content-Language: en-US
To:     Lukasz Luba <lukasz.luba@arm.com>
Cc:     amit.kachhap@gmail.com, viresh.kumar@linaro.org, rafael@kernel.org,
        amitk@kernel.org, rui.zhang@intel.com, dietmar.eggemann@arm.com,
        Pierre.Gondois@arm.com, Matthias Kaehlcke <mka@chromium.org>,
        Doug Anderson <dianders@chromium.org>,
        linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20220207073036.14901-1-lukasz.luba@arm.com>
 <20220207073036.14901-2-lukasz.luba@arm.com>
 <4e090ffe-c19b-8e2c-0396-72dc33361f35@arm.com>
 <211a3606-2f4c-227b-33aa-177ef68a49a3@arm.com>
 <3d1719ca-d4a4-f904-e284-b857414669ba@linaro.org>
 <27df4e4f-b6d7-9a58-f2dd-d6afa748e217@arm.com>
From:   Daniel Lezcano <daniel.lezcano@linaro.org>
In-Reply-To: <27df4e4f-b6d7-9a58-f2dd-d6afa748e217@arm.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk


Hi Lukasz,

On 22/02/2022 19:31, Lukasz Luba wrote:
> 
> 
> On 2/22/22 18:12, Daniel Lezcano wrote:
>>
>> Hi Lukasz,
>>
>> I don't think it makes sense to remove the support of the energy model 
>> if the units are abstracts.
>>
>> IIUC, regarding your previous answer, we don't really know what will 
>> do the SoC vendor with these numbers and likely they will provide 
>> consistent abstract values which won't prevent a correct behavior.
>>
>> What would be the benefit of giving inconsistent abstract values which 
>> will be unusable except of giving a broken energy model?
> 
> The power values in the EM which has abstract scale, would make sense to 
> EAS, but not for IPA or DTPM. Those platforms which want to enable EAS,
> but don't need IPA, would register such '<a_good_name_here>' EM.

Sorry, but I don't understand why DTPM can not deal with abstract values?


>> Your proposed changes would be acceptable if the energy model has a 
>> broken flag IMO
> 
> That is doable. I can add that flag, so we can call it 'artificial' EM
> (when this new flag is set).

It is too soon IMO, I would like to see the numbers first so we can take 
an enlighten decision. Right now, it is unclear what the numbers will be.


> Let me craft the RFC patch with this new flag proposal then.
> Do you agree? Can I also add you as 'Suggested-by'?
> 
> Thank you for coming back to me with the comments.


-- 
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog