Re: [PATCH v1 03/10] ARM: tegra: acer-a500: Bump thermal trips by 10C

From: Dmitry Osipenko
Date: Tue Jun 15 2021 - 08:53:36 EST


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.