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

[Geert Uytterhoeven]

Hi Marek,

On Thu, 23 Oct 2025 at 14:37, Marek Vasut
<marek.vasut+renesas at mailbox.org> wrote:
> Document new property arm,poll-transport, which sets all SCMI operation into
> poll mode. This is meant to work around uncooperative SCP implementations,
> which do not generate completion interrupts. This applies primarily on mbox
> based implementations, but does also cover SMC and VirtIO ones.
>
> With this property set, such implementations which do not generate interrupts
> can be interacted with, until they are fixed to generate interrupts properly.
>
> Note that, because the original base protocol exchange also requires some
> sort of completion mechanism, it is not possible to query SCMI itself for
> this property and it must be described in DT. While this does look a bit
> like policy, the SCMI provider is part of the hardware, hence DT.
>
> Signed-off-by: Marek Vasut <marek.vasut+renesas at mailbox.org>

Thanks for your patch!

> --- 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

meant

> +      completion interrupts.
> +
>    arm,smc-id:
>      $ref: /schemas/types.yaml#/definitions/uint32
>      description:

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds