[PATCH 1/2] dt-bindings: firmware: arm,scmi: Document arm,poll-transport property

Marek Vasut marek.vasut at mailbox.org
Thu Oct 23 06:57:51 PDT 2025


On 10/23/25 3:42 PM, Sudeep Holla wrote:

Hello Sudeep,

>>> diff --git a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
>>> index be817fd9cc34b..b53754a318ea1 100644
>>> --- a/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
>>> +++ b/Documentation/devicetree/bindings/firmware/arm,scmi.yaml
>>> @@ -146,6 +146,13 @@ properties:
>>>         this platform. If set, the value should be non-zero.
>>>       minimum: 1
>>>   
>>> +  arm,poll-transport:
>>> +    type: boolean
>>> +    description:
>>> +      An optional property which unconditionally forces polling in all transports.
>>> +      This is mainly mean to work around uncooperative SCP, which does not generate
>>> +      completion interrupts.
>>> +
>>
>> Could you please clarify which platform and transport this change pertains to?
>>
>> Introducing a property that enforces unconditional polling across all
>> platforms is not ideal - particularly if this is intended as a workaround
>> for a platform- or firmware- specific issue. Such implementations often get
>> replicated across platforms without addressing the root cause, leading to
>> wider inconsistencies.
>>
> 
> Just to clarify what I mean by "enforces unconditional polling" is with the
> added DT property only. I understand this is new property and it much be
> present in DT to enforce polling, but it can be misused initially for testing
> in absence of interrupt support and forgotten in DT. Hence my concern.

I would argue about the "mis" part of "misused" . It can be both "used" 
and "misused". I can add stronger warning into the description ?

-- 
Best regards,
Marek Vasut



More information about the linux-arm-kernel mailing list