On Thu, Jun 30, 2022 at 04:37:50PM +0000, Conor.Dooley@microchip.com wrote:

On 30/06/2022 11:39, Sudeep Holla wrote:

quoted

I can't think of any reason for that to happen unless detect_cache_attributes
is failing from init_cpu_topology and we are ignoring that.

Are all RISC-V platforms failing on -next or is it just this platform ?

I don't know. I only have SoCs with this core complex & one that does not
work with upstream. I can try my other board with this SoC - but I am on
leave at the moment w/ a computer or internet during the day so it may be
a few days before I can try it.

Sure, no worries.

However, Niklas Cassel has tried to use the Canaan K210 on next-20220630
but had issues with RCU stalling:
https://lore.kernel.org/linux-riscv/Yr3PKR0Uj1bE5Y6O@x1-carbon/T/#m52016996fcf5fa0501066d73352ed8e806803e06 (local)
Not going to claim any relation, but that's minus 1 to the platforms that
can be used to test this on upstream RISC-V.

Ah OK, will check and ask full logs to see if there is any relation.

quoted

We may have to try with some logs in detect_cache_attributes,
last_level_cache_is_valid and last_level_cache_is_shared to check where it
is going wrong.

It must be crashing in smp_callin->update_siblings_masks->last_level_cache_is_shared

Yeah, I was playing around last night for a while but didn't figure out the
root cause. I'll try again tonight.

OK, thanks for that. I tried qemu, but doesn't have any cache info in DT
provided by qemu itself. The other sifive_u machine didn't work on qemu,
only virt booted with mainline as well.

In the meantime, would you mind taking the patches out of -next?

I don't want to take out as we will loose all the test coverage.
I would like to know if any other RISC-V platform is affected or not
before removing it.

FWIW I repro'd the failure on next-20220630.

Yes, nothing has changed yet.

--
Regards,
Sudeep

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