Re: [PATCH v2 2/5] dt-bindings: iommu: mediatek: Fix interrupt count constraint for new SoCs

[AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>]

Il 02/10/24 07:01, Macpaul Lin ha scritto:
> 
> 
> On 9/30/24 16:49, AngeloGioacchino Del Regno wrote:
>> Il 26/09/24 13:14, Macpaul Lin ha scritto:
>>> The infra-iommu node in mt8195.dtsi was triggering a CHECK_DTBS error due
>>> to an excessively long 'interrupts' property. The error message was:
>>>
> 
> [snip]
> 
>>>
>>> diff --git a/Documentation/devicetree/bindings/iommu/mediatek,iommu.yaml 
>>> b/Documentation/devicetree/bindings/iommu/mediatek,iommu.yaml
>>> index ea6b0f5f24de..fdd2996d2a31 100644
>>> --- a/Documentation/devicetree/bindings/iommu/mediatek,iommu.yaml
>>> +++ b/Documentation/devicetree/bindings/iommu/mediatek,iommu.yaml
>>> @@ -96,7 +96,8 @@ properties:
>>>       maxItems: 1
>>>     interrupts:
>>> -    maxItems: 1
>>> +    minItems: 1
>>> +    maxItems: 5
>>>     clocks:
>>>       items:
>>> @@ -210,6 +211,28 @@ allOf:
>>>         required:
>>>           - mediatek,larbs
>>> +  - if:
>>> +      properties:
>>> +        compatible:
>>> +          contains:
>>> +            enum:
>>> +              - mediatek,mt8195-iommu-infra
>>> +
>>> +    then:
>>> +      properties:
>>> +        interrupts:
>>> +          description: |
>>
>> Do you really need to keep the formatting?
>>
>> If you rephrase that as:
>>
>> The infra IOMMU in MT8195 has five banks: each features one set
>> of APB registers for the normal world (set 0), one
> 
> Shouldn't we use a 'three' here?

Oops, yes, that's three. I wrote 'one' but described three. Heh!

> Three APB register sets for the protected world 1, protected world 2,
> and protected world 3.

three APB register sets for the protected world (sets 1/2/3) -- or
three APB register sets for the protected world (sets 1-3)

I mean, repeating "protected world X" three times is too much I think :-)

> 
>> for the protected
>> world (sets 1-3) and one for the secure world (set 4), and each set
>> has its own interrupt. Therefore, five interrupts are needed.
>>
>> ...you won't need the bar :-)
> 
> Thanks for the suggestion. The description has been moved to
> top common property in v3, and v4,
> hence the bar is still required to explain the
> others SOCs. I'll try to rephrase the description for MT8195 also.

Sure. You're welcome!

> 
>>> +            The IOMMU of MT8195 has 5 banks: 0/1/2/3/4.
>>> +            Each bank has a set of APB registers corresponding to the
>>> +            normal world, protected world 1/2/3, and secure world, respectively.
>>> +            Therefore, 5 interrupt numbers are needed.
>>> +          maxItems: 5
>>
>> minItems: 5
>>
>> Cheers,
>> Angelo
>>
>>
> 
> Thanks
> Macpaul Lin