Re: [PATCH v3 2/2] arm64: dts: qcom: x1e78100-t14s: Add thermal zones for keyboard skin and charging sensors

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] The DT thermal zones are completely non-functional because the backing EC driver does not register its sensors with the thermal framework. The driver (`drivers/platform/arm64/lenovo-thinkpad-t14s.c`) registers a hwmon device using `devm_hwmon_device_register_with_info()` but fails to include the `HWMON_C_REGISTER_TZ` attribute under a `hwmon_chip` channel, nor does it explicitly call `devm_thermal_of_zone_register()`. The hwmon core requires `HWMON_C_REGISTER_TZ` to automatically register thermal zones. Consequently, the DT thermal zones remain permanently unbound, and the CPU thermal throttling described in the commit will not execute.
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commit 7064bd8ea5ff8a561ac7494d4e760b120e4d6d03
Author: Daniel Lezcano <daniel.lezcano@oss.qualcomm.com>

arm64: dts: qcom: x1e78100-t14s: Add thermal zones for keyboard skin and charging sensors

This commit exposes the embedded controller temperature sensors as thermal
zones in the device tree for the Lenovo ThinkPad T14s. It maps the charging
thermal zone to CPU cooling devices, allowing the generic thermal framework
to apply throttling when temperatures exceed the passive threshold.

> diff --git a/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi b/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi
> index 5d49df41be02a..a19a363da9ed5 100644
> --- a/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi
> +++ b/arch/arm64/boot/dts/qcom/x1e78100-lenovo-thinkpad-t14s.dtsi

[ ... ]

> @@ -1729,3 +1731,67 @@ &usb_mp_qmpphy1 {
>  
>  	status = "okay";
>  };
> +
> +&thermal_zones {
> +	ec-keyboard-thermal {
> +		polling-delay = <5000>;
> +		polling-delay-passive = <1000>;
> +
> +		thermal-sensors = <&ec 1>;

[Severity: High]
Will these thermal zones successfully bind to the embedded controller?

Looking at the underlying driver in
drivers/platform/arm64/lenovo-thinkpad-t14s.c, it registers a hwmon device
using devm_hwmon_device_register_with_info() but does not appear to include
the HWMON_C_REGISTER_TZ attribute under a hwmon_chip channel. It also doesn't
seem to explicitly call devm_thermal_of_zone_register().

Without the HWMON_C_REGISTER_TZ attribute, the hwmon core will not
automatically register these thermal zones. Does this mean the DT thermal
zones remain permanently unbound, preventing the CPU thermal throttling
described in the commit message from actually executing?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260701103714.22583-1-daniel.lezcano@oss.qualcomm.com?part=2