Re: [PATCH v7 00/10] arm64: dts: Add Arm Morello support

Sudeep Holla
2025-02-25T12:07:21Z

Hi Mark,

Thanks for raising valid points/concerns.

On Mon, Feb 24, 2025 at 10:08:18AM +0000, Vincenzo Frascino wrote:
> Hello Mark,
>
> On 21/02/2025 18:54, Mark Rutland wrote:
> > Hi Vincenzo,
> >
> > On Fri, Feb 21, 2025 at 06:03:39PM +0000, Vincenzo Frascino wrote:
> >> The Morello architecture is an experimental extension to Armv8.2-A,
> >> which extends the AArch64 state with the principles proposed in
> >> version 7 of the Capability Hardware Enhanced RISC Instructions
> >> (CHERI) ISA [1].
> >
> > None of the CHERI stuff is supported upstream, so from upstream's PoV
> > this is a low-volume dev-board/SoC with an experimental ARMv8.2-A CPU.
> >

I understand and agree with your concerns.

>
> Agreed, I have no plans to upstream Morello support beyond the device tree.
>
> >> This series adds dts support for the Arm Morello System Development
> >> Platform.
> >
> > Do we actually need the dts for this board?
> >
> > I have one on my desk; it boots vanilla Debian 12 via UEFI + ACPI just
> > fine, with the Debian 6.1.0-13-arm64 kernel.
> >
> > Is there something that we can only do with the DT? i.e. some
> > functionality that isn't exposed via ACPI?
> >
> > How do you expect this DT to be used?
> >
>
> There are functionalities that are not exposed via ACPI, e.g. gpu, dpu, i2c for
> the phy, etc. My aim to have upstream support for all the hardware exposed by
> the platform.
>

Does this address some of your concerns ? I do understand some of these
are not well addressed in ACPI and hence people use DT as an alternative.

> Note: This series contains only the basic infrastructure, the plan is add
> progressively more features in the future.
>

I was thinking of queuing this in -next if all the bindings are acked.
Let me know if you still have concerns and would like to avoid getting
these merged. I will hold off then.

--
Regards,
Sudeep