Re: [PATCH v6 8/9] arm64: dts: qcom: kodiak: Describe EUD UTMI path using child node

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [High] Nesting the OF graph inside `eud-path@0` breaks the existing `qcom_eud` driver's ability to find the USB role switch, and violates the current device tree binding.
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--- Patch [8]: [PATCH v6 8/9] arm64: dts: qcom: kodiak: Describe EUD UTMI path using child node ---
commit 760fcd42e7f50583cc87820f4812ba19895c4e27
Author: Elson Serrao <elson.serrao@oss.qualcomm.com>

arm64: dts: qcom: kodiak: Update EUD device tree graph

This commit updates the EUD description to explicitly model the topology
using an eud path child node. It also associates the endpoint mapping
with the primary controller and enables the EUD by default.

> diff --git a/arch/arm64/boot/dts/qcom/kodiak.dtsi b/arch/arm64/boot/dts/qcom/kodiak.dtsi
> index f2da3706d5c8..30b62b406906 100644
> --- a/arch/arm64/boot/dts/qcom/kodiak.dtsi
> +++ b/arch/arm64/boot/dts/qcom/kodiak.dtsi

[ ... ]

> @@ -4753,16 +4747,28 @@ eud: eud@88e0000 {
>  			      <0 0x88e2000 0 0x1000>;
>  			interrupts-extended = <&pdc 11 IRQ_TYPE_LEVEL_HIGH>;
>  
> -			status = "disabled";
> +			#address-cells = <1>;
> +			#size-cells = <0>;
>  
> -			ports {
> -				#address-cells = <1>;
> -				#size-cells = <0>;
> +			eud0: eud-path@0 {
> +				reg = <0>;
> +				usb-role-switch;
>  
> -				port@0 {
> -					reg = <0>;
> -					eud_ep: endpoint {
> -						remote-endpoint = <&usb2_role_switch>;
> +				ports {

[Severity: High]
Will this nested structure prevent the qcom_eud driver from finding the
USB role switch?

In drivers/usb/misc/qcom_eud.c:eud_probe(), the driver calls
usb_role_switch_get(), which traverses the OF graph to locate the switch:

    chip->role_sw = usb_role_switch_get(&pdev->dev);
    if (IS_ERR(chip->role_sw))

The graph traversal functions look specifically for immediate child nodes
named "port" or "ports". Because this patch nests the "ports" node inside
an "eud-path@0" child, the traversal will find zero endpoints. This will
cause usb_role_switch_get() to silently return NULL and leave the debugging
functionality non-functional.

Additionally, does this change violate the current device tree bindings for
the EUD?

The schema in Documentation/devicetree/bindings/soc/qcom/qcom,eud.yaml
specifies "additionalProperties: false", which will reject properties like
"eud-path@0", "#address-cells", and "#size-cells" at the root of the eud
node.

> +					#address-cells = <1>;
> +					#size-cells = <0>;
> +
> +					port@0 {
> +						reg = <0>;
> +						eud_usb: endpoint {
> +							remote-endpoint = <&usb_1_dwc3_hs>;
> +						};
> +					};

[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260811213610.2956147-1-elson.serrao@oss.qualcomm.com?part=8