Re: [PATCH v4 09/10] dt-bindings: display: rockchip: dw-dp: Fix sound DAI cells

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] Unconditional ABI breakage of `#sound-dai-cells` in Device Tree binding.
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--- Patch [9]: [PATCH v4 09/10] dt-bindings: display: rockchip: dw-dp: Fix sound DAI cells ---
commit 3829785f7403edd4d5c1e524c76b4c78f5cf26da
Author: Sebastian Reichel <sebastian.reichel@collabora.com>

dt-bindings: display: rockchip: dw-dp: Fix sound DAI cells

This commit updates the rockchip dw-dp binding to change #sound-dai-cells
from 0 to 1, allowing the selection between I2S and S/PDIF. The example is
also updated to reflect this new required cell count.

> diff --git a/Documentation/devicetree/bindings/display/rockchip/rockchip,dw-dp.yaml b/Documentation/devicetree/bindings/display/rockchip/rockchip,dw-dp.yaml
> index 2b0d9e23e9432..c4f8959dd65da 100644
> --- a/Documentation/devicetree/bindings/display/rockchip/rockchip,dw-dp.yaml
> +++ b/Documentation/devicetree/bindings/display/rockchip/rockchip,dw-dp.yaml
[ ... ]
> @@ -83,7 +83,8 @@ properties:
>      maxItems: 1
>  
>    "#sound-dai-cells":
> -    const: 0
> +    const: 1
> +    description: 0 for I2S, 1 for S/PDIF

[Severity: Medium]
Will this unconditional constraint change cause a regression by breaking
Device Tree ABI backward compatibility?

Existing in-tree device trees such as
arch/arm64/boot/dts/rockchip/rk3588-base.dtsi still define the property with
0 cells:

arch/arm64/boot/dts/rockchip/rk3588-base.dtsi:dp0 {
	...
	resets = <&cru SRST_DP0>;
	#sound-dai-cells = <0>;
	status = "disabled";
}

A similar definition exists in
arch/arm64/boot/dts/rockchip/rk3588-extra.dtsi for dp1.

Could this update lead to immediate dtbs_check validation failures and break
audio initialization for users booting with older, previously valid DTBs?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260721-synopsys-dw-dp-improvements-v4-0-f0f4a4ede712@collabora.com?part=9