Re: [PATCH v3 1/3] dt-bindings: pci: ultrarisc: add required DP1000 PCIe clocks

[sashiko-bot@kernel.org]

Thank you for your contribution! Sashiko AI review found 1 potential issue(s) to consider:

Pre-existing issues:
- [High] Missing driver clock management. The DP1000 PCIe driver fails to implement support for the newly mandated `core`, `dbi`, and `aux` clocks, leading to unclocked hardware register accesses.
--

--- Patch [1]: [PATCH v3 1/3] dt-bindings: pci: ultrarisc: add required DP1000 PCIe clocks ---
commit 04ce10fff5fc6c7c7dc6e7380ab1ae6a1209bb14
Author: Jia Wang <wangjia@ultrarisc.com>

dt-bindings: pci: ultrarisc: add required DP1000 PCIe clocks

This commit mandates that DP1000 PCIe controller nodes provide the standard
DesignWare clock names "core", "dbi", and "aux" in the device tree bindings.

> diff --git a/Documentation/devicetree/bindings/pci/ultrarisc,dp1000-pcie.yaml b/Documentation/devicetree/bindings/pci/ultrarisc,dp1000-pcie.yaml
> --- a/Documentation/devicetree/bindings/pci/ultrarisc,dp1000-pcie.yaml
> +++ b/Documentation/devicetree/bindings/pci/ultrarisc,dp1000-pcie.yaml
> @@ -43,6 +43,18 @@ properties:
[ ... ]
> +  clocks:
> +    items:
> +      - description: PCIe core clock
> +      - description: Data Bus Interface (DBI) clock
> +      - description: Auxiliary clock
> +
> +  clock-names:
> +    items:
> +      - const: core
> +      - const: dbi
> +      - const: aux

[Severity: High]
This is a pre-existing issue, but since these clocks are now formally required
by the binding, does the pcie-ultrarisc driver also need to be updated to
manage them?

Looking at drivers/pci/controller/dwc/pcie-ultrarisc.c, ultrarisc_pcie_probe()
does not appear to fetch or enable these clocks. Because of this, hardware
registers are accessed before clocks are explicitly enabled by the driver:

drivers/pci/controller/dwc/pcie-ultrarisc.c:ultrarisc_pcie_host_init() {
    ...
    val = dw_pcie_readl_dbi(pci, PCIE_CUS_CORE);
    ...
}

Will this unclocked hardware register access trigger a synchronous bus error
and kernel panic during the device probe path on boot?

-- 
Sashiko AI review · https://sashiko.dev/#/patchset/20260714-ultrarisc-pci-clk-v3-0-e72723fc0ef1@ultrarisc.com?part=1