[U-Boot] [PATCH] clk: sifive: Fix ethernet regression on HiFive Unleashed

[Bin Meng]

Hi Marcus,

On Sun, Sep 8, 2019 at 10:48 PM Marcus Comstedt <marcus at mc.pp.se> wrote:
>
>
> Hi Bin,
>
> Bin Meng <bmeng.cn at gmail.com> writes:
>
> >> And which "Linux DTB" should that be?  Since RISC-V seems to be going
> >
> > The one in arch/riscv/boot/dts/sifive.
>
> Yes, but in which Linux?  This whole thing started because U-Boot will

The latest Linux kernel v5.3.

> no longer accept the DTB used with Linux 4.14.  If each Linux version is

I checked kernel 4.14 and found it did not ship the SiFive Unleased
board DTS in the kernel tree. Are you sure it's 4.14?

> going to have its own incompatible DTB then U-Boot either needs to
> decide which one to work with, or work with the vendor DTB (which
> would be perferable in my opinion).
>
>
> > As for the syntax of the nodes keep changing, I would say that's
> > inevitable because of the upstreaming process. Everything in vendor's
> > DT that does not get merged in Linux will remain potentially changed
> > by later upstreaming reviews.
>
> An upstreaming review that suggests changing a driver so that it no
> longer works with the vendor's DTB is IMHO contraproductive and
> against the very idea of DTB, but I suppose there's little that can be

I don't think Linux is to be blamed for this case. They have a policy
to maintain the the backward compatibility for the DT land. The issue
what you were facing here is an out of tree DTB (the vendors') is
incompatible with the kernel's. Once the kernel accepts a DTS,
bringing in any out-of-tree DT with changes reviewed to in-tree,
future compatibility will be assured.

> done to affect the review process over at Linux land...  It would be
> nice if this weirdness did not spill over on U-Boot/OpenSBI though.

Regards,
Bin