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

[Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>]

On 9/28/26 4:04 PM, sashiko-bot@kernel.org wrote:
> 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
that is correct, I ended up sending some stale patches. will be fixed in v5.
> - [Medium] dts: Panel power sequencing issue due to premature backlight enable

this is same across other glymur dts.

--srini
> --
> 
> 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>;
>> +				};
>> +			};
>> +		};
>> +	};
>> +};
>