Re: [PATCH v3 2/3] x86/fpu: Add a helper to prepare AMX state for low-power CPU idle

[Chang S. Bae]

On 4/3/2022 9:37 AM, Thomas Gleixner wrote:
> On Thu, Mar 24 2022 at 19:22, Chang S. Bae wrote:
> > When a CPU enters an idle state, non-initialized states left in large
> > registers may be the cause of preventing deeper low-power states.
> >
> > The new helper ensures the AMX state is initialized to make the CPU
> > ready for low-power states. It will be used by the intel idle driver.
>
> What about AVX...AVX512? Are they harmless in that regard?

I double-checked with HW folks. Yes, that's the case. Their state 
whether initialized or not does not prevent the processor from entering 
a deeper low-power state.

> If so, then the first sentence above is confusing and should clearly
> spell out that it's AMX which causes that problem.

I see. Will do that.

Thanks,
Chang