Re: [PATCH] firmware: arm_scmi: Give SMC transport precedence over mailbox

[Sudeep Holla <sudeep.holla@arm.com>]

On Sat, Oct 05, 2024 at 09:33:17PM -0700, Florian Fainelli wrote:
> Broadcom STB platforms have for historical reasons included both
> "arm,scmi-smc" and "arm,scmi" in their SCMI Device Tree node compatible
> string.
>

I assume in the same order.

> After the commit cited in the Fixes tag and with a kernel
> configuration that enables both the SCMI and the Mailbox transports, we

^^^^^ s/SCMI/SMC ?

> would probe the mailbox transport, but fail to complete since we would
> not have a mailbox driver available.
>

I always assumed the node compatible match happens from the more specific
compatible(on the left) to the more generic ones(on the right) from the
compatible property list. Looks like that was a wrong assumption then ?

> By keeping the SMC transport objects linked first, we can let the
> platform driver, match the compatible string and probe successfully with
> no adverse effects on platforms using the mailbox transport.
>

I don't have strong objection to the patch itself, happy to get it merged.
Just curious if my understanding of the issue is correct. I think Cristian
has more detailed query, so just responding to that will suffice.

> Fixes: b53515fa177c ("firmware: arm_scmi: Make MBOX transport a standalone driver")
> Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>
> Change-Id: I8e348e3e0deabdc5c1d596929d7f9134793f346e

Spurious from internal gerrit repo ?

--
Regards,
Sudeep