Hi Robin,
On 13/08/2021 15:51, Robin Murphy wrote:
> On 2021-08-13 13:59, Daniel Lezcano wrote:
>> On 30/07/2021 17:17, Peter Geis wrote:
>>> The rockpro64 had a fan node since
>>> commit 5882d65c1691 ("arm64: dts: rockchip: Add PWM fan for RockPro64")
>>> however it was never tied into the thermal driver for automatic control.
>>>
>>> Add the links to the thermal node to permit the kernel to handle this
>>> automatically.
>>> Borrowed from the (rk3399-khadas-edge.dtsi).
>>>
>>> Signed-off-by: Peter Geis <pgwipeout@xxxxxxxxx>
[ ... ]
>>> +&cpu_thermal {
>>> + trips {
>>> + cpu_warm: cpu_warm {
>>> + temperature = <55000>;
>>> + hysteresis = <2000>;
>>> + type = "active";
>>> + };
>>> +
>>> + cpu_hot: cpu_hot {
>>> + temperature = <65000>;
>>> + hysteresis = <2000>;
>>> + type = "active";
>>> + };
>>> + };
>>> +
>>
>> Why two trip points ?
>>
>> Why not one functioning temperature and no lower / upper limits for the
>> cooling maps ?
>
> Certainly when I first did this for NanoPC-T4, IIRC it was to avoid the
> fan ramping up too eagerly, since level 1 for my fan is effectively
> silent but still cools enough to let a moderate load eventually settle
> to a steady state below the second trip.
Thanks for your answer.
What would be the governor for this setup ?
--
<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
