[PATCH v2 15/15] arm64: dts: mediatek: mt8188: add default thermal zones

[Daniel Lezcano]

On 21/05/2024 13:10, Julien Panis wrote:
> Hello Daniel,
> 
> On 4/4/24 17:16, Daniel Lezcano wrote:
>>
>> Hi Nico,
>>
>> a few comments about this description.
>>
>> On 02/04/2024 05:25, Nicolas Pitre wrote:
>>> From: Nicolas Pitre <npitre at baylibre.com>
>>>
>>> Inspired by the vendor kernel but adapted to the upstream thermal
>>> driver version.
>>
>> [ ... ]
>>
>>> +    thermal_zones: thermal-zones {
>>> +        cpu-little0-thermal {
>>> +            polling-delay = <1000>;
>>
>> Except if I'm wrong, the driver supports the interrupt mode, so it not 
>> necessary to poll constantly when there is no mitigation. You can 
>> remove the line and everywhere else.
>>
>>> +            polling-delay-passive = <250>;
>>
>> As little CPU, 200ms or 150ms may be more adequate.
>>
>>> +            thermal-sensors = <&lvts_mcu MT8188_MCU_LITTLE_CPU0>;
>>> +
>>> +            trips {
>>> +                cpu_little0_alert: trip-alert {
>>> +                    temperature = <85000>;
>>> +                    hysteresis = <2000>;
>>> +                    type = "passive";
>>> +                };
>>
>> You may want to add a 'hot' trip point in between, so the userspace 
>> can be notified and take an action before reaching 'critical' (like 
>> unplugging a CPU)
> 
> There's no "notify" function in the driver.

The trip point crossing is always notified to userspace in the core 
code. It is not driver specific.

> Do you think it's worth adding such 'hot' trip point, though ?

Having this trip point would allow generic trip point handling in a 
userspace daemon to do an action.

If the userspace does not take care of this event, it won't hurt.



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