Re: [PATCH 12/24] dt-bindings: PCI: Add ZTE ZX279128S host controller

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:
- [Medium] pci: dwc: shared reset GPIO model forces usage of deprecated NONEXCLUSIVE flag
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commit 3cd514331eb31d5c998faa82fe1883e6405d010c
Author: Navid Ghahremani <ghahramani.navid@gmail.com>

dt-bindings: PCI: Add ZTE ZX279128S host controller

Describe both DesignWare hosts, the two control syscons and the shared
Wi-Fi reset lines. The shared-resource model remains an RFC question.

> diff --git a/Documentation/devicetree/bindings/pci/zte,zx279128s-pcie.yaml b/Documentation/devicetree/bindings/pci/zte,zx279128s-pcie.yaml
> new file mode 100644
> index 0000000000000..57a4e966109c5
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/pci/zte,zx279128s-pcie.yaml
[ ... ]
> +  reset-gpios:
> +    maxItems: 1
> +    description: Board reset line. A device connected to both controllers
> +      (the MT7915 Wi-Fi chip of the ZTE ZXHN H3600) has its lines listed in
> +      both nodes; the first controller to start resets and releases it.
> +
> +  enable-gpios:
> +    maxItems: 1
> +    description: Second board line that is driven together with reset-gpios.

[Severity: Medium]
Does this shared reset GPIO model force the driver to use a deprecated GPIO API?

Modeling a shared Wi-Fi endpoint reset line by duplicating the reset-gpios and
enable-gpios properties across both PCIe host controller nodes forces the
driver to use GPIOD_FLAGS_BIT_NONEXCLUSIVE to avoid an -EBUSY exclusive claim
probe failure.

include/linux/gpio/consumer.h explicitly marks GPIOD_FLAGS_BIT_NONEXCLUSIVE as
"DEPRECATED, don't use in new code", and its use in new code is strictly
forbidden by the GPIO subsystem.

Should this shared resource instead be handled via the reset controller
subsystem, power sequencing (pwrseq), or represented directly on the endpoint
node rather than duplicating host-level GPIO properties?

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Sashiko AI review · https://sashiko.dev/#/patchset/20261010130024.177503-1-ghahramani.navid@gmail.com?part=12