Re: [PATCH v8 07/11] arm64: dts: renesas: rzg2l(c)/rzv2l hb-iiot: add dsi panel dt overlay

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Low] Device Tree overlay encodes a software workaround for a driver bug by specifying incorrect GPIO polarity.
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commit 5ed903b02819c317254f3303f8a8204c435744da
Author: Josua Mayer <josua@solid-run.com>

arm64: dts: renesas: rzg2l(c)/rzv2l hb-iiot: add dsi panel dt overlay

This commit adds a Device Tree overlay for the Winstar WJ70N3TYJHMNG0 DSI
panel on SolidRun HummingBoard IIoT boards. It includes the new dtso file
and updates the Makefile for supported SoC targets.

> diff --git a/arch/arm64/boot/dts/renesas/rzg2l-hummingboard-iiot-panel-dsi-WJ70N3TYJHMNG0.dtso b/arch/arm64/boot/dts/renesas/rzg2l-hummingboard-iiot-panel-dsi-WJ70N3TYJHMNG0.dtso
> new file mode 100644
> index 0000000000000..f8584c473fafe
> --- /dev/null
> +++ b/arch/arm64/boot/dts/renesas/rzg2l-hummingboard-iiot-panel-dsi-WJ70N3TYJHMNG0.dtso

[ ... ]

> +&dsi {
> +	#address-cells = <1>;
> +	#size-cells = <0>;
> +	status = "okay";
> +
> +	panel@0 {
> +		/* This is a Winstar panel, but the ronbo panel uses same controls. */
> +		compatible = "ronbo,rb070d30";
> +		reg = <0>;
> +		/* reset is active-low but driver inverts it internally */
> +		reset-gpios = <&tca6408_u48 1 GPIO_ACTIVE_HIGH>;

[Severity: Low]
Does this encode a software workaround directly into the hardware description?

Device trees are meant to describe the physical hardware. If the reset line
is physically active-low, shouldn't the device tree describe it as
GPIO_ACTIVE_LOW?

If the 'ronbo,rb070d30' panel driver incorrectly inverts this internally,
that appears to be a driver bug. Could this be fixed in the driver code
rather than compensated for with incorrect polarity in the bindings?

> +		backlight = <&dsi_backlight>;
> +		power-gpios = <&tca6408_u48 2 GPIO_ACTIVE_HIGH>;
> +		shlr-gpios = <&tca6408_u48 4 GPIO_ACTIVE_LOW>;

[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260904-rzg2-sr-boards-v8-0-94c4674927e8@solid-run.com?part=7