Messages in this thread | | | Subject | Re: [PATCH 9/9] ARM: dts: uniphier: Remove compatible "snps,dw-pcie-ep" from Pro5 pcie-ep node | From | Kunihiko Hayashi <> | Date | Tue, 2 Aug 2022 22:10:53 +0900 |
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On 2022/08/02 17:33, Krzysztof Kozlowski wrote: > On 30/07/2022 13:58, Arnd Bergmann wrote: >> On Mon, Jul 4, 2022 at 2:20 AM Kunihiko Hayashi >> <hayashi.kunihiko@socionext.com> 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?
In term of the binding, it seems that the current binding doesn't allow descriptions that list two compatibles. There is something wrong with the binding.
> 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.
In term of the controller, we can add dw general compatible if the more generic driver (pcie-designware-plat) works on the controller.
However, the generic driver can't do the initialization what the controller needs, so we can add controller-specific compatible only. The commit bf2942a8b7c3 ("arm64: tegra: Fix Tegra194 PCIe EP compatible string") removes the generic compatible for the same reason.
This patch suggests removing the generic compatible for the former reason, though, I might suggest it for the controller reason.
Thank you,
--- Best Regards Kunihiko Hayashi
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