Re: [PATCH 1/2] arm64: dts: qcom: hamoa-iot-evk: Add eDP display overlay

[email protected]
Newsgroups org.kernel.vger.linux-devicetree
Message-ID <[email protected]>
Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
- [Medium] The `/delete-property/ #sound-dai-cells;` directive in the DT overlay is ineffective because standard device tree overlays do not support property deletion.
- [Low] The eDP backlight PWM controller (`pmk8550_pwm`) is unintentionally left enabled in the headless base DTB.
--

--- Patch [1]: [PATCH 1/2] arm64: dts: qcom: hamoa-iot-evk: Add eDP display overlay ---
commit 820f4e5720b8cbcecbbe4eead917eaa1fbedcf0e
Author: Anand Tiwari <[email protected]>

arm64: dts: qcom: hamoa-iot-evk: Add eDP display overlay

Move the eDP panel configuration and related power, backlight, and pinctrl
nodes into a separate overlay. Keep the base DTB suitable for headless
variants and provide a composite DTB for headed variants.

> diff --git a/arch/arm64/boot/dts/qcom/hamoa-iot-evk-edp.dtso b/arch/arm64/boot/dts/qcom/hamoa-iot-evk-edp.dtso
> new file mode 100644
> index 0000000000000..759d05342627f
> --- /dev/null
> +++ b/arch/arm64/boot/dts/qcom/hamoa-iot-evk-edp.dtso
[ ... ]
> +&mdss_dp3 {
> +	/delete-property/ #sound-dai-cells;

[Severity: Medium]
Will this /delete-property/ directive actually remove the property from the
base tree when merging the overlay?

Standard device tree overlays do not support property deletion. When compiled
with dtc, this deletion directive is evaluated against the local overlay AST
where the property does not exist, and is silently discarded. The .dtbo
format lacks a deletion opcode, so the property will remain enabled in the
composite device tree, potentially causing DT schema validation errors or
incorrect audio subsystem probing.

[ ... ]
> diff --git a/arch/arm64/boot/dts/qcom/hamoa-iot-evk.dts b/arch/arm64/boot/dts/qcom/hamoa-iot-evk.dts
> index 9fa86bb6438ec..78cefd5391b17 100644
> --- a/arch/arm64/boot/dts/qcom/hamoa-iot-evk.dts
> +++ b/arch/arm64/boot/dts/qcom/hamoa-iot-evk.dts
[ ... ]
> -&pmk8550_gpios {
> -	edp_bl_pwm: edp-bl-pwm-state {
> -		pins = "gpio5";
> -		function = "func3";
> -	};
> -};
> -
>  &pmk8550_pwm {
>  	status = "okay";
>  };

[Severity: Low]
Should this status override for pmk8550_pwm have been removed from the base
device tree?

Since the backlight consumer and GPIO configurations have been moved to the
overlay, leaving pmk8550_pwm enabled here keeps it active on headless
variants without any consumers. It is also redundantly enabled in the new
overlay.

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/[email protected]?part=1
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