Re: [PATCH v4 04/18] dt-bindings: PCI: rcar-gen4: Add optional "aer" interrupt for R-Car Gen4 SoCs

[Marek Vasut <marek.vasut@mailbox.org>]

On 10/15/26 5:30 AM, Koichiro Den wrote:
> The intreq_pcim_lperr interrupt carries Root Port AER notifications,
> separately from the integrated MSI receiver interrupt. Describe it with
> the "aer" name so the controller driver can use it for Root Port error
> reporting.
> 
> Keep the fifth interrupt optional on R-Car Gen4 SoCs so existing device
> trees remain valid. Extend the example accordingly.
> 
> Signed-off-by: Koichiro Den <den@valinux.co.jp>
> ---
> Changes since v3:
>    - Rebase on Marek's Gen5 AER binding fix:
>      https://lore.kernel.org/r/20261003215710.792518-1-marek.vasut+renesas@mailbox.org/
>      This requires "aer" for the Gen5 SoC PCIe4 controller from the
>      beginning. Update the subject to clarify that it is optional only
>      on Gen4 SoCs, for compatibility with existing DTs.
>    - Drop R-b tags due to the changes.
> 
> v3: https://lore.kernel.org/r/20261006084638.3821710-5-den@valinux.co.jp/
> 
>   .../devicetree/bindings/pci/rcar-gen4-pci-host.yaml | 13 ++++++++++---
>   1 file changed, 10 insertions(+), 3 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/pci/rcar-gen4-pci-host.yaml b/Documentation/devicetree/bindings/pci/rcar-gen4-pci-host.yaml
> index 083b77d4de8f..a86c06701fa9 100644
> --- a/Documentation/devicetree/bindings/pci/rcar-gen4-pci-host.yaml
> +++ b/Documentation/devicetree/bindings/pci/rcar-gen4-pci-host.yaml
> @@ -26,7 +26,8 @@ properties:
>             - const: renesas,rcar-gen5-pcie4 # R-Car Gen5 PCIe4
>   
>     interrupts:
> -    maxItems: 4
> +    minItems: 4
> +    maxItems: 5

Wouldn't it be easier/cleaner keep only maxItems: 4 here and set ...

>     clocks:
>       maxItems: 2
> @@ -93,11 +94,13 @@ allOf:
>               - const: config
>   
>           interrupt-names:
> +          minItems: 4

... minItems/maxItems here ^ for R-Car Gen4 (because Gen4 is the only 
SoC family which has optional non-mandatorily-described AER interrupt) ...

>             items:
>               - const: msi
>               - const: dma
>               - const: sft_ce
>               - const: app
> +            - const: aer
>     - if:
>         properties:
>           compatible:
> @@ -117,6 +120,9 @@ allOf:
>               - const: app
>               - const: config
>   
> +        interrupts:
> +          maxItems: 4

... and drop this interrupts: hunk here entirely (because Gen5 always 
has mandatorily described AER interrupt) ?

>           interrupt-names:
>             items:
>               - const: msi
> @@ -146,8 +152,9 @@ examples:
>               interrupts = <GIC_SPI 416 IRQ_TYPE_LEVEL_HIGH>,
>                            <GIC_SPI 417 IRQ_TYPE_LEVEL_HIGH>,
>                            <GIC_SPI 418 IRQ_TYPE_LEVEL_HIGH>,
> -                         <GIC_SPI 422 IRQ_TYPE_LEVEL_HIGH>;
> -            interrupt-names = "msi", "dma", "sft_ce", "app";
> +                         <GIC_SPI 422 IRQ_TYPE_LEVEL_HIGH>,
> +                         <GIC_SPI 421 IRQ_TYPE_LEVEL_HIGH>;
> +            interrupt-names = "msi", "dma", "sft_ce", "app", "aer";
>               clocks = <&cpg CPG_MOD 624>, <&pcie0_clkref>;
>               clock-names = "core", "ref";
>               power-domains = <&sysc R8A779F0_PD_ALWAYS_ON>;

What do you think ?