Re: [PATCH 1/2] thermal: cooling: Check Energy Model type in cpufreq_cooling and devfreq_cooling

From: Lukasz Luba <lukasz.luba@arm.com>
To: daniel.lezcano@linaro.org
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
Subject: Re: [PATCH 1/2] thermal: cooling: Check Energy Model type in cpufreq_cooling and devfreq_cooling
Date: Tue, 22 Feb 2022 17:05:13 +0000	[thread overview]
Message-ID: <211a3606-2f4c-227b-33aa-177ef68a49a3@arm.com> (raw)
In-Reply-To: <4e090ffe-c19b-8e2c-0396-72dc33361f35@arm.com>

Hi Daniel,

gentle ping

On 2/17/22 18:18, Lukasz Luba wrote:
> Hi Daniel,
> 
> 
> On 2/7/22 7:30 AM, Lukasz Luba wrote:
>> The Energy Model supports power values either in Watts or in some 
>> abstract
>> scale. When the 2nd option is in use, the thermal governor IPA should not
>> be allowed to operate, since the relation between cooling devices is not
>> properly defined. Thus, it might be possible that big GPU has lower power
>> values in abstract scale than a Little CPU. To mitigate a misbehaviour
>> of the thermal control algorithm, simply not register a cooling device
>> capable of working with IPA.
>>
>> Signed-off-by: Lukasz Luba <lukasz.luba@arm.com>
>> ---
>>   drivers/thermal/cpufreq_cooling.c |  2 +-
>>   drivers/thermal/devfreq_cooling.c | 16 +++++++++++++---
>>   2 files changed, 14 insertions(+), 4 deletions(-)
> 
> The discussion in below this patch went slightly off-topic but it was
> valuable. It clarified also there are no broken platforms with this
> change.
> 
> Could you take the patch into the thermal tree, please?
> 
> Regards,
> Lukasz