Re: [PATCH v7 15/16] 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] Removal of the `wifi@0` device tree node silently breaks Wake-on-WLAN (WoWLAN) capability for the MT7921 WiFi device.
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--- Patch [15]: [PATCH v7 15/16] arm64: dts: mediatek: mt8195-cherry: Add M.2 E-key slot ---
commit f3cf400c3b922d9936d6cc4d1a7c83d4b85941b6
Author: Chen-Yu Tsai <wenst@chromium.org>

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

The Mt8195 Cherry design features an M.2 E-key slot for WiFi/BT combo cards.
This patch adds the proper representation for it, replacing the PCIe wifi node
and supply properties under the PCIe controller and xhci3 nodes.

> diff --git a/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi b/arch/arm64/boot/dts/mediatek/mt8195-cherry.dtsi
> --- 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 silently break Wake-on-WLAN capability for the
MT7921 WiFi device?

Looking at the driver in mt7921/pci.c, it probes the device and explicitly
checks for the wakeup-source property on its associated device tree node.

Since the wifi@0 node is completely replaced by the OF graph port node here,
which does not represent a PCI device and has no reg property, it appears
the PCI core will no longer assign an OF node to the MT7921 device. Will
this cause the wakeup-source check to fail and leave WoWLAN permanently
disabled?

>  	};
>  };

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260724084328.3943997-1-wenst@chromium.org?part=15