Re: [PATCH v11 3/6] arm64: dts: allwinner: Add Allwinner H616 .dtsi file

Jernej Škrabec
2022-07-07T16:40:09Z

Dne četrtek, 07. julij 2022 ob 08:30:32 CEST je Samuel Holland napisal(a):
> Hi Andre, Jernej,
>
> On 7/6/22 8:16 AM, Andre Przywara wrote:
> > so after seemingly having finished writing this email, I realised that
> > this won't really help, as I think this diverts the discussion. And the
> > problem has been around for a while, and won't probably be solved easily
> > or quickly. I think we agree to disagree here, or we should admit that
> > there are different approaches ("bundled firmware" vs. "UEFI"), so in the
> > interest of not blocking the H616 series:
> >
> > Shall I just keep the firmware node? This would work both ways, whereas
> > dropping the node would impede the "bundled firmware" approach?
>
> Let me try to sum up the relevant portion of my thoughts (and save the rest
> for elsewhere):
>
> The only reason to add the reserved-memory node is to support
> externally-loaded DTBs. By adding the node, we are committing to support
> externally-loaded DTBs on this SoC.
>
> Upgrading the kernel is not allowed to break boot. If we support
> externally-loaded DTBs, that rule extends to DTBs shipped with the kernel.
>
> If we remove the reserved-memory node, the combination of old U-Boot + new
> externally-loaded DTB will stop booting (the kernel version is irrelevant).
> Therefore, if we add the node, we can never remove it, full stop.
>
> I will (begrudgingly) accept that, as long as the node matches what TF-A
> actually generates today. That means, please:
> - Drop the label and update the node name
> - Reduce the size to 256 KiB, matching (BL31_LIMIT - BL31_BASE)

In the interest of moving things forward, I agree to that.

Best regards,
Jernej