Re: [PATCH V2 04/14] LoongArch: Adjust boot & setup for 32BIT/64BIT

[Huacai Chen]

On Wed, Nov 19, 2025 at 2:03 PM Jiaxun Yang <jiaxun.yang@xxxxxxxxxxx> wrote:
>
>
>
> On Wed, 19 Nov 2025, at 12:28 PM, Huacai Chen wrote:
> [...]
> >> Per the schema for LoongArch CPUs (loongarch/cpus.yaml), "clocks"
> >> property is also described as mandantory, thus I don't think such
> >> fallback makes sense.
> > Yes, "clocks" is mandatory in theory, but sometimes is missing in
> > practice, at least in QEMU. On the other hand, if "clocks" really
> > always exist, then the error checking in fdt_cpu_clk_init() can also
> > be removed. So the fallback makes sense.
>
> IMHO this should be fixed on QEMU side, but I recall QEMU do have clock
> supplied in generic fdt?
It is difficult to fix, you can have a try. :)
If without fallback, cpuinfo shows 0MHz now.

>
> >
> > Why pick 200MHz? That is because we assume the constant timer is
> > 100MHz (which is true for all real machines), 200MHz is the minimal
> > multiple of 100MHz, it is more reasonable than 0MHz.
>
> Maybe better panic here :-)
No, this is not a fatal error, we don't need to treat everything as
fatal. As you know, many "BUG_ON" have been replaced with "WARN_ON" in
kernel.

Huacai

>
> Thanks
> --
> - Jiaxun
>