Re: [RFC PATCH] platform/arm64: lenovo-thinkpad-t14s: Adjust thermal trip with platform profile

[Kurt Borja]

On Wed Oct 14, 2026 at 10:03 AM -03, Daniel Lezcano wrote:
> On 10/14/26 12:19, Ilpo Järvinen wrote:
>> + more people.

Hi all,

>> 
>> On Thu, 1 Oct 2026, Daniel Lezcano wrote:
>> 
>>> Tie the keyboard thermal mitigation temperature to the platform profile
>>> selected through the ThinkPad embedded controller.
>>>
>>> The EC reports Fn+L, Fn+M and Fn+H events corresponding to low-power,
>>> balanced and performance operating modes. Use these events to update the
>>> passive trip point of the "keyboard-thermal" zone to 49.85°C, 57.85°C
>>> and 59.85°C respectively.
>>>
>>> These thresholds match the thermal mitigation temperatures used by the
>>> platform for the corresponding operating profiles.
>>>
>>> Look up the keyboard thermal zone at probe time and locate the passive
>>> trip named "keyboard-ec-alert". The trip name is used deliberately so
>>> the EC driver can identify the device-tree trip associated with the
>>> platform thermal profile without depending on its position in the trip
>>> table.
>>>
>>> Initialize the thermal mitigation threshold to the balanced profile,
>>> matching the default platform behaviour, and update the thermal zone
>>> whenever a profile change event is reported by the EC so that the new
>>> mitigation temperature takes effect immediately.
>>>
>>> Using the platform_profile API would provide a more appropriate interface
>>> for exposing and managing these operating modes. However, while the API
>>> itself is generic, the platform profile core implementation currently
>>> lives under the ACPI framework. Making it available to device-tree based
>>> platforms requires separating the generic infrastructure from ACPI,
>>> which is a larger and independent piece of work.
>> 
>> So the only problem is that platform profile resides underneath acpi
>> namespace in sysfs?
>
> Yes but I have a series I'm about to send decoupling the 
> platform_profile from ACPI

The platform-profile already has a platform agnostic interface at
/sys/class/platform-profile-N. Unless I'm missing something, I believe
that interface should already cover your use case and its also the
recommended way to expose interfaces to user-space.

I was not around here when this functionality was exposed to
/sys/firmware/acpi so I don't really know the context, but I personally
don't see a reason to duplicate this at /sys/firmware/devicetree or
something like that.

-- 
Thanks,
 ~ Kurt