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

[Julien Panis]

On 5/21/24 16:07, AngeloGioacchino Del Regno wrote:
> Il 21/05/24 13:31, Daniel Lezcano ha scritto:
>> 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.
>>
>>
>>
>
> Hello Julien,
>
> I'll push two series tomorrow to add most of the power domains (all but the
> img_vcore ones, as those require a bit more work), the two vdosys and, more
> importantly, support for the GPU in both panfrost and the MT8188 devicetree.
>
> Actually, if it's not tomorrow, it's going to be on Monday - though I'm not
> sure why you feel like you're blocked by not having the GPU node in there.
>
> Cheers,
> Angelo

Hello Angelo,

Sorry, I sent the v4 a few seconds before receiving your email. :)

OK for the GPU support, thanks. After that, I'll submit a v5 that will include
the related cooling-device. IIUC, this should look something like that:

cooling-maps {
     map0 {
         trip = <&gpu1_alert0>;
         cooling-device = <&gpu THERMAL_NO_LIMIT THERMAL_NO_LIMIT>;
     }
}

That's why I need some 'gpu' node somewhere in the device tree.
The build fails without it.

Julien