[PATCH v8 03/10] arm_ffa: introduce Arm FF-A low-level driver

Sudeep Holla sudeep.holla at arm.com
Thu Jan 19 18:09:45 CET 2023

On Thu, Jan 19, 2023 at 11:57:44AM -0500, Tom Rini wrote:
> But it's also true that at run-time, within U-Boot, we can modify the
> device tree we have, with live tree yes? So, the whole series in
> question here can be done without modifying the base DT and getting in
> to the further discussions that doing so entails. The assertion is that
> the software discoverable bus here is sufficient to not need DT, so, OK,
> lets go.

OK, may be I am not up-to-date on the U-Boot. IIUC, the modifications
done in the DT by U-Boot is mostly for consumption by the next stage
loader/OS and not for self-consumption. But if it is for self consumption,
then good. It helps especially for the subnodes(as Simon referred) or the
partitions that can be discovered at run-time using FF-A interface.

As mentioned I am not again DT, it is just not needed and especially
for subnodes it could result in inconsistency b/w what is in DT and
what the firmware provides. As mentioned in previous response, having a
simple node that Simon provided as example earlier is fine by me if that
is the only option to make progress as I just feel it is redundant and
one can say not scalable(but that is debatable again 😄).

In short, I am not concerned about having simple node, just don't like
to see entire FF-A bus enumerated in DT as subnodes for reasons mentioned


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