Re: [PATCH 1/4] arm64: tegra: Add PWM fan on Jetson AGX Orin DevKit

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] The patch introduces a platform mismatch by modifying the device tree for the Jetson AGX Thor (Tegra264) while the commit message targets the Jetson AGX Orin (Tegra234). This causes a fatal Device Tree compilation error because the `&pwm4` phandle is not defined in the Tegra264 base tree. Additionally, it maps a PWM node at `0xc6a0000`, which collides with the existing `i2c9` controller's MMIO region in Tegra264.
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commit 5abc2fdc061c1ce5d90cefc286641978583847de
Author: Thierry Reding <treding@nvidia.com>

arm64: tegra: Add PWM fan on Jetson AGX Orin DevKit

This commit adds a PWM fan device node to actively control the PWM,
preventing the fan from either stopping or running at full speed during boot.

> diff --git a/arch/arm64/boot/dts/nvidia/tegra264-p4071-0000+p3834.dtsi b/arch/arm64/boot/dts/nvidia/tegra264-p4071-0000+p3834.dtsi
> index 45f8df9bbfd62..4550e843f513c 100644
> --- a/arch/arm64/boot/dts/nvidia/tegra264-p4071-0000+p3834.dtsi
> +++ b/arch/arm64/boot/dts/nvidia/tegra264-p4071-0000+p3834.dtsi
> @@ -9,4 +9,17 @@ aliases {
>  	chosen {
>  		stdout-path = "serial0:115200n8";
>  	};
> +
> +	bus@0 {
> +		pwm@c6a0000 {

[Severity: Medium]
The commit message targets the Jetson AGX Orin (Tegra234) platform, but this
patch modifies the device tree for the Jetson AGX Thor (Tegra264) in
arch/arm64/boot/dts/nvidia/tegra264-p4071-0000+p3834.dtsi.

Does this unit address assignment correctly overlay the bus@0/pwm@c6a0000 node?
In the Tegra264 platform, the 0xc6a0000 address is already allocated to the
i2c9 controller (i2c@c6a0000), which creates an MMIO region collision.

> +			status = "okay";
> +		};
> +	};
> +
> +	fan: pwm-fan {
> +		compatible = "pwm-fan";
> +		cooling-levels = <77 102 140 192 255>;
> +		pwms = <&pwm4 0 40000>;

[Severity: Medium]
Will this compile when building the device tree for the Tegra264 platform
with make dtbs?

The &pwm4 phandle used here in the pwm-fan node is not defined in the Tegra264
base device tree. Referencing an undefined label causes a Device Tree Compiler
(dtc) abort.

> +		#cooling-cells = <2>;
> +	};
>  };

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260827-tegra264-fan-v1-0-3c55f0c748b1@nvidia.com?part=1