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

[Marcus Comstedt <marcus@mc.pp.se>]

Hi Bin,

Bin Meng <bmeng.cn@gmail.com> writes:

>> Yes, but in which Linux?  This whole thing started because U-Boot will
>
> The latest Linux kernel v5.3.

Thanks.  I'll try it later.  As if to prove my point, the one from
5.2.11 (which is the Linux version I'm currently running) did not work
(I got MMC but no ethernet)...


> 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?

It's the one shipped with the H5U, which I'm pretty sure ran Linux
4.14 at the time (as part of the "Freedom U SDK") since 4.15 was not
out yet.  It looks like SiFive never added the DTS to their own Linux
tree (https://github.com/sifive/riscv-linux).


> 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.

Isn't the reason that the DTS accepted by the kernel is different from
the out-of-tree vendor one that the review process caused changes in
the DTS then?  It seems unlikely that the vendor (SiFive) would
deliberately submit an incompatible DTS for inclusion...


  // Marcus