Re: [PATCH 9/9] ARM: dts: uniphier: Remove compatible "snps,dw-pcie-ep" from Pro5 pcie-ep node

[Krzysztof Kozlowski]

On 30/07/2022 13:58, Arnd Bergmann wrote:
> On Mon, Jul 4, 2022 at 2:20 AM Kunihiko Hayashi
> <hayashi.kunihiko@xxxxxxxxxxxxx> wrote:
>>
>> UniPhier PCIe endpoint controller doesn't use "snps,dw-pcie-ep" compatible,
>> so this is no longer needed. Remove the compatible string from the pcie-ep
>> node to fix the following warning.
>>
>>   uniphier-pro5-epcore.dtb: pcie@66000000: compatible: ['socionext,uniphier-pro5-pcie-ep', 'snps,dw-pcie-ep'] is too long
>>       From schema: Documentation/devicetree/bindings/pci/socionext,uniphier-pcie-ep.yaml
>>
> 
> This sounds like a problem with the binding rather than the dt file. Is this not
> a designware pci endpoint? Should it be documented in that binding instead?

Depends. We had one or two similar cases, where we dropped the snps/dw
generic compatible, because device was actually quite different and
could not match against snps/dw compatible. IOW, if device bound/matched
via generic compatible it would be entirely non-operational. Logically I
think it is okay to drop the generic compatible. Different question is
any ABI break.

Best regards,
Krzysztof