[RFC PATCH] platform: generic: thead: add sfence workaroud for th1520/sg2042

[Jessica Clarke]

On 14 Sep 2023, at 01:26, Inochi Amaoto <inochiama at outlook.com> wrote:
> 
>>> so they need to execute sfence.vma in the trap handler to
>>> function properly.
>>> 
>>> To handle this workaroud, add a degraded alternative mechanism in the thead
>>> platform to patch the trap handler.
>> 
>> Don’t mess up generic code for this, just override the trap handler and
>> branch to the generic one after whatever workaround you supposedly need
>> for unclear reasons?
>> 
> 
> Thanks for this advice, I will try a platform trap handler.
> 
>> But this needs a much clearer explanation of whatever’s going on here,
>> which sounds like a spec violation being described to me. What exactly
>> is the hardware erratum and where is it documented?
>> 
>> Jess
>> 
> 
> This is more like a implementation issue rather than spec violation.

Those are two names for the same thing.

Jess

> AFAIK, only th1520 and sg2042 are affected.
> 
> Thanks,
> Inochi