Re: [PATCH] x86/ACPI/cstate: Allow ACPI C1 FFH MWAIT use on AMD systems

From: Borislav Petkov
Date: Tue May 23 2017 - 09:06:27 EST


On Tue, May 23, 2017 at 12:50:15PM +0000, Ghannam, Yazen wrote:
> No, AMD systems will continue to use HLT unless the BIOS specifies the
> use of MWAIT using a FFH entry in the ACPI _CST.
>
> All this change does is *allow* us to use MWAIT through the FFH
> implementation if the BIOS defines it. It doesn't *force* a change.

So that could very well be part of the commit message as it explains
what exactly you're changing.

> If the BIOS doesn't define the appropriate _CST entry or it defines it
> wrong, then we'll fallback to using HLT.

I'm assuming you've tested it on older families to make sure they still
work as expected? I wouldn't trust the BIOS...

--
Regards/Gruss,
Boris.

ECO tip #101: Trim your mails when you reply.
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