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Subject: Re: [PATCH v1 03/10] ARM: tegra: acer-a500: Bump thermal trips by 10C
To:     Daniel Lezcano <daniel.lezcano@linaro.org>,
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        Svyatoslav Ryhel <clamor95@gmail.com>,
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From:   Dmitry Osipenko <digetx@gmail.com>
Message-ID: <60a280c3-e67f-ff3a-9f0e-7d12fc125c5b@gmail.com>
Date:   Tue, 15 Jun 2021 15:53:29 +0300
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13.06.2021 21:19, Daniel Lezcano пишет:
> On 13/06/2021 02:25, Dmitry Osipenko wrote:
> 
> [ ... ]
> 
>>> You should set the trip points close to the functioning boundary
>>> temperature given in the hardware specification whatever the resulting
>>> heating effect is on the device.
>>>
>>> The thermal zone is there to protect the silicon and the system from a
>>> wild reboot.
>>>
>>> If the Nexus 7 is too hot after the changes, then you may act on the
>>> sources of the heat. For instance, set the the highest OPP to turbo or
>>> remove it, or, if there is one, change the thermal daemon to reduce the
>>> overall power consumption.
>>> In case you are interested in: https://lwn.net/Articles/839318/
>>
>> The DTPM is a very interesting approach. For now Tegra still misses some
>> basics in mainline kernel which have a higher priority, so I think it
>> should be good enough to perform the in-kernel thermal management for
>> the starter. We may consider a more complex solutions later on if will
>> be necessary.
>>
>> What I'm currently thinking to do is:
>>
>> 1. Set up the trips of SoC/CPU core thermal zones in accordance to the
>> silicon limits.
>>
>> 2. Set up the skin trips in accordance to the device limits.
>>
>> The breached skin trips will cause a mild throttling, while the SoC/CPU
>> trips will be allowed to cause the severe throttling. Does this sound
>> good to you?
> 
> The skin temperature must be managed from userspace. The kernel is
> unable to do a smart thermal management given different thermal zones
> but if the goal is to go forward and prevent the tablet to be hot
> temporarily until the other hardware support is there, I think it is
> acceptable.

The current goal is to get maximum from what we already have, thank you.