Re: [PATCH v2 4/5] arm64: dts: renesas: r9a09g087: Add DU node

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 3 potential issue(s) to consider:
- [High] Missing the required `resets` property in the `du` node, leading to a driver probe failure.
- [Medium] Missing a fallback compatible string for the `du` node.
- [Low] The device tree compilation fails due to the use of an undeclared macro `R9A09G087_LCDC_CLKD`.
--

commit 60fe4c07204f3af15bb869a850f5f3764a505646
Author: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>

arm64: dts: renesas: r9a09g087: Add DU node

This commit adds the Display Unit node to the r9a09g087 device tree.

> diff --git a/arch/arm64/boot/dts/renesas/r9a09g087.dtsi b/arch/arm64/boot/dts/renesas/r9a09g087.dtsi
> index cb2eabe3242e0..21250caf31493 100644
> --- a/arch/arm64/boot/dts/renesas/r9a09g087.dtsi
> +++ b/arch/arm64/boot/dts/renesas/r9a09g087.dtsi
> @@ -1272,6 +1272,30 @@ sdhi1_vqmmc: vqmmc-regulator {
>  			};
>  		};
>  
> +		du: display@920c0000 {
> +			compatible = "renesas,r9a09g087-du", "renesas,r9a09g077-du";

[Severity: Medium]
Does this node need a recognized fallback compatible string?

Neither "renesas,r9a09g087-du" nor "renesas,r9a09g077-du" are present in
the display driver's match table, and no existing fallback string
is provided. Without a recognized fallback, the device will fail to match
with the driver entirely, preventing the display unit from probing.

> +			reg = <0 0x920c0000 0 0x10000>;
> +			interrupts = <GIC_SPI 781 IRQ_TYPE_LEVEL_HIGH>;

[Severity: High]
Does this node need a resets property?

The renesas,rzg2l-du.yaml schema strictly requires the resets property.
Furthermore, the display driver in drivers/gpu/drm/renesas/rz-du/
unconditionally attempts to acquire the reset control via:

    devm_reset_control_get_shared(rcdu->dev, NULL)

Because the resets property is absent, this returns -ENOENT, which aborts
the driver probe and renders the display subsystem unusable.

> +			clocks = <&cpg CPG_CORE R9A09G087_CLK_PCLKAH>,
> +				 <&cpg CPG_MOD 1204>,
> +				 <&cpg CPG_CORE R9A09G087_LCDC_CLKD>;

[Severity: Low]
Is the R9A09G087_LCDC_CLKD macro defined in the dt-bindings headers?

This macro is used as a clock specifier but does not appear to be defined
in the repository, causing the preprocessor to output the macro name as a
literal string. This results in a syntax error from dtc which expects a
phandle or integer.

> +			clock-names = "aclk", "pclk", "vclk";

[ ... ]

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260615115455.1412098-1-prabhakar.mahadev-lad.rj@bp.renesas.com?part=4