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

Marek Vasut marek.vasut at mailbox.org
Thu Oct 23 06:42:02 PDT 2025


On 10/23/25 3:16 PM, Sudeep Holla wrote:

Hello Sudeep,

>> +  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?

Renesas X5H with older SCP firmware , accessible via mailbox.

> 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.

The root cause is being addressed already, this is meant to keep the 
older SCP version operable.

> It would be preferable to scope this behavior using the platform’s compatible
> string. This approach ensures the workaround is applied only to the affected
> platform and prevents it from being inadvertently enabled elsewhere, unless
> another platform intentionally uses the same compatible string (which seems
> unlikely).

This is not platform-specific issue. SCMI provider which fails to 
generate interrupts can appear on any platform, using either transport, 
that is why I made the property generic.

-- 
Best regards,
Marek Vasut



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