Re: [PATCH v16 1/7] dt-bindings: arm: Add support for Qualcomm TGU trace

["Songwei.Chai" <songwei.chai@oss.qualcomm.com>]

On 7/30/2026 4:15 PM, sashiko-bot@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 2 potential issue(s) to consider:
> - [Medium] The binding schema omits the `interrupts` property despite the hardware description explicitly stating it can generate interrupts.

Clarification：

The current driver/DTS does not actually use an interrupt line (it only 
uses CTI trigger outputs), so there is no need for the binding to define 
an |interrupts| property.

> - [Low] The schema claims `arm,primecell` compatibility but uses `additionalProperties: false` without referencing the standard Primecell schema, incorrectly blocking valid Primecell properties.
> --

Clarification:

 1. I checked the format of the |arm,coresight-*.yaml| files under
    |Documentation/devicetree/bindings/arm/| and found that they all
    claim |arm,primecell| compatibility, yet none of them reference
    |/schemas/arm/primecell.yaml|.
 2. In actual DTS files, properties defined by the PrimeCell schema,
    such as |arm,primecell-periphid|, do not normally appear. Therefore,
    referencing |/schemas/arm/primecell.yaml| is not mandatory.

>
> --- Patch [1]: [PATCH v16 1/7] dt-bindings: arm: Add support for Qualcomm TGU trace ---
> commit 1cb0b1557ad8efca643aa36dee2d1b84f9c415b0
> Author: Songwei Chai <songwei.chai@oss.qualcomm.com>
>
> dt-bindings: arm: Add support for Qualcomm TGU trace
>
> This commit introduces the device tree binding schema for the Qualcomm
> Trigger Generation Unit (TGU). The TGU monitors signals to identify issues
> and can generate a trigger into the CTI or interrupts to processors.
>
>> diff --git a/Documentation/devicetree/bindings/arm/qcom,tgu.yaml b/Documentation/devicetree/bindings/arm/qcom,tgu.yaml
>> new file mode 100644
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/arm/qcom,tgu.yaml
> [ ... ]
>> +description: |
>> +  The Trigger Generation Unit (TGU) is a Data Engine which can be utilized
>> +  to sense a plurality of signals and create a trigger into the CTI or
>> +  generate interrupts to processors. The TGU is like the trigger circuit
> [ ... ]
>> +  preprogrammed state/sequence and then produce a trigger or interrupt.
> [ ... ]
>> +properties:
>> +  compatible:
>> +    items:
>> +      - const: qcom,tgu
>> +      - const: arm,primecell
> [Severity: Low]
> Since this device claims arm,primecell compatibility, shouldn't there be a
> schema reference to /schemas/arm/primecell.yaml# included to properly
> inherit standard PrimeCell properties?
>
>> +
>> +  reg:
>> +    maxItems: 1
>> +
>> +  clocks:
>> +    maxItems: 1
>> +
>> +  clock-names:
>> +    items:
>> +      - const: apb_pclk
> [Severity: Medium]
> The description above mentions the hardware can "produce a trigger or
> interrupt", but an interrupts property is missing from this list.
>
> Will device trees that legitimately specify the hardware's interrupt line
> fail schema validation when additionalProperties: false is enforced below?
>
>> +
>> +required:
>> +  - compatible
>> +  - reg
>> +  - clocks
>> +  - clock-names
>> +
>> +additionalProperties: false
> [Severity: Low]
> Because arm,primecell compatibility is claimed, should this use
> unevaluatedProperties: false instead?
>
> Using additionalProperties: false without inheriting the PrimeCell schema
> will block valid inherited properties like arm,primecell-periphid from
> being used in the device tree without validation errors.
>