Re: [PATCH v3 2/3] arm64: dts: qcom: Add Lenovo ThinkPad T14s Gen 7

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [High] dts: Reset GPIO conflict between ptn3222_1 and ptn3222_cam
- [Medium] dts: Panel power sequencing issue due to premature backlight enable
--

commit c99537659e637d229456f818bb7c8fc0b3d7fcf3
Author: Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>

arm64: dts: qcom: Add Lenovo ThinkPad T14s Gen 7
    
Introduce a device tree for the Mahua-based Lenovo ThinkPad T14s Gen 7,
a Snapdragon X2 Elite laptop.  It follows the Qualcomm Glymur reference
design used by mahua-crd.

> diff --git a/arch/arm64/boot/dts/qcom/mahua-lenovo-thinkpad-t14s-gen7-lcd.dts b/arch/arm64/boot/dts/qcom/mahua-lenovo-thinkpad-t14s-gen7-lcd.dts
> new file mode 100644
> index 0000000000000..26d6d8285e040
> --- /dev/null
> +++ b/arch/arm64/boot/dts/qcom/mahua-lenovo-thinkpad-t14s-gen7-lcd.dts
> @@ -0,0 +1,1272 @@
[ ... ]
> +	ptn3222_1: redriver@4b {
> +		compatible = "nxp,ptn3222";
> +		reg = <0x4b>;
> +
> +		reset-gpios = <&tlmm 184 GPIO_ACTIVE_LOW>;
> +
> +		vdd3v3-supply = <&vreg_l8b_e0_3p3>;
> +		vdd1v8-supply = <&vreg_l15b_e0_1p8>;
> +
> +		#phy-cells = <0>;
> +	};
> +
> +	ptn3222_cam: redriver@47 {
> +		compatible = "nxp,ptn3222";
> +		reg = <0x47>;
> +
> +		reset-gpios = <&tlmm 184 GPIO_ACTIVE_LOW>;

[Severity: High]
Could this GPIO assignment conflict with ptn3222_1 above?

The ptn3222 driver requests the reset GPIO exclusively during probe via
devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH). Because the GPIO
subsystem prevents sharing an exclusive GPIO by default, assigning the same
GPIO to both redrivers could cause one of them to deterministically fail to
probe with a -EBUSY error.

> +
> +		vdd3v3-supply = <&vreg_l8b_e0_3p3>;
> +		vdd1v8-supply = <&vreg_l15b_e0_1p8>;
> +
> +		#phy-cells = <0>;
> +	};
[ ... ]
> +	aux-bus {
> +		panel {
> +			compatible = "edp-panel";
> +			enable-gpios = <&tlmm 18 GPIO_ACTIVE_HIGH>;
> +			power-supply = <&vreg_edp_3p3>;
> +
> +			pinctrl-0 = <&edp_bl_en>;
> +			pinctrl-names = "default";

[Severity: Medium]
Will this cause visual artifacts during boot or resume?

It appears the backlight enable GPIO (tlmm 18) is passed here as the panel's
logic power enable. The panel-edp driver asserts enable-gpios in
panel_edp_prepare_once() before the eDP link is trained and valid video data
is streaming. Bypassing proper eDP DPCD and backlight sequencing could turn
the backlight on prematurely.

> +
> +			port {
> +				edp_panel_in: endpoint {
> +					remote-endpoint = <&mdss_dp3_out>;
> +				};
> +			};
> +		};
> +	};
> +};

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260928145122.1337186-1-srinivas.kandagatla@oss.qualcomm.com?part=2