Re: [PATCH v9 14/15] arm64: dts: mediatek: mt8195-cherry: Add M.2 E-key slot

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] pci: implicit loss of WoWLAN support due to wifi@0 node removal
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commit 5f7e95ba7e04fe3e98237e1ef5a8952a18138c2e
Author: Chen-Yu Tsai <wenst@chromium.org>

arm64: dts: mediatek: mt8195-cherry: Add M.2 E-key slot

This commit adds the proper representation for the M.2 E-key slot on the Mt8195
Cherry design, which is used for WiFi/BT combo cards. It replaces the existing
PCIe wifi node and moves the associated supply properties.

> diff --git a/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi b/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi
> index ef7afc436aefc..8d4cc30d91e44 100644
> --- a/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi
> +++ b/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi
[ ... ]
> @@ -791,14 +832,14 @@ pcie@0 {
>  		reg = <0 0 0 0 0>;
>  		device_type = "pci";
>  		num-lanes = <1>;
> -		vpcie3v3-supply = <&pp3300_wlan>;
>  		#address-cells = <3>;
>  		#size-cells = <2>;
>  		ranges;
>  
> -		wifi@0 {
> -			reg = <0 0 0 0 0>;
> -			wakeup-source;
> +		port {
> +			pcie1_ep: endpoint {
> +				remote-endpoint = <&wifi_ep>;
> +			};
>  		};
>  	};
>  };

[Severity: Medium]
Does removing the wifi@0 node and its wakeup-source property silently disable
Wake-on-WLAN support for the MT7921 PCIe driver?

The MT7921 PCIe driver (drivers/net/wireless/mediatek/mt76/mt7921/pci.c)
relies on dev->mt76.dev->of_node to check for this property and enable
Wake-on-WLAN via device_init_wakeup().

Because the PCI device node is removed and replaced only with an OF graph
port inside the root port pcie@0, the PCI core (pci_set_of_node) will no
longer find a matching child node to assign to pdev->dev.of_node.

Consequently, it appears the driver will fail to read wakeup-source, which
could cause a functional regression in power management.

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Sashiko AI review · https://sashiko.dev/#/patchset/20260916075745.3549953-1-wenst@chromium.org?part=14