Re: [PATCH 04/28] arm64: dts: qcom: sdm845: Fix swapped USB QMP PHY vdda-phy/vdda-pll supplies

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] The patch fixes swapped `vdda-phy` and `vdda-pll` supplies for USB QMP PHYs on SDM845 boards but overlooks SDM850 boards, which suffer from the exact same hardware misconfiguration.
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--- Patch [4]: [PATCH 04/28] arm64: dts: qcom: sdm845: Fix swapped USB QMP PHY vdda-phy/vdda-pll supplies ---
commit bbec7ae85a9540fb8dbd59aa76f0e1c5b71911a4
Author: Manivannan Sadhasivam <[email protected]>

arm64: dts: qcom: sdm845: Fix swapped USB QMP PHY vdda-phy/vdda-pll supplies

This commit swaps the vdda-phy and vdda-pll supplies back to their proper
voltage levels for USB QMP PHYs on various SDM845 boards. It corrects a
misconfiguration where the PHY was incorrectly fed 1.2V and the PLL was
fed 0.88V.

> diff --git a/arch/arm64/boot/dts/qcom/sdm845-db845c.dts b/arch/arm64/boot/dts/qcom/sdm845-db845c.dts
> index 02416812b6a7f..846138149b2cd 100644
> --- a/arch/arm64/boot/dts/qcom/sdm845-db845c.dts
> +++ b/arch/arm64/boot/dts/qcom/sdm845-db845c.dts
> @@ -1121,8 +1121,8 @@ &usb_1_hsphy {
>  &usb_1_qmpphy {
>  	status = "okay";
>  
> -	vdda-phy-supply = <&vreg_l26a_1p2>;
> -	vdda-pll-supply = <&vreg_l1a_0p875>;
> +	vdda-phy-supply = <&vreg_l1a_0p875>;
> +	vdda-pll-supply = <&vreg_l26a_1p2>;

[Severity: High]
This isn't a bug introduced by this patch, but this patch appears to miss the
identical sibling SDM850 platforms, leaving their PHYs operating with inverted
voltage supplies. Should the SDM850 boards also be updated to prevent hardware
stability issues?

For example, on the Huawei Matebook E 2019
(arch/arm64/boot/dts/qcom/sdm850-huawei-matebook-e-2019.dts), the primary and
secondary USB QMP PHYs still have their supplies swapped:

&usb_1_qmpphy {
	...
	vdda-phy-supply = <&vdda_usb1_ss_1p2>;
	vdda-pll-supply = <&vdda_usb1_ss_core>;
};

&usb_2_qmpphy {
	...
	vdda-phy-supply = <&vdda_usb2_ss_1p2>;
	vdda-pll-supply = <&vdda_usb2_ss_core>;
};

The same misconfiguration is present in sdm850-lenovo-yoga-c630.dts and
sdm850-samsung-w737.dts. Does this leave the vdda-phy logic on these boards
overvolted by ~36% (1.2V instead of 0.88V) and the analog PLL undervolted
(0.88V instead of 1.2V)? Could this lead to decreased hardware stability,
PLL unlock issues, or long-term degradation of the silicon?

>  };

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=4