On Mon, Mar 08, 2021 at 12:41:26PM +0000, Andrew Cooper wrote:
> On 05/03/2021 09:50, Jan Beulich wrote:
> > Linux has been warning ("firmware bug") about this bit being clear for a
> > long time. While writable in older hardware it has been readonly on more
> > than just most recent hardware. For simplicitly report it always set (if
> > anything we may want to log the issue ourselves if it turns out to be
> > clear on older hardware).
> >
> > Signed-off-by: Jan Beulich <jbeul...@suse.com>
> 
> I realise Linux is complaining, but simply setting the bit isn't a fix.
> 
> This needs corresponding updates in the ACPI tables, as well as Pstate
> MSRs, or Linux will derive a false relationship between the TSC rate and
> wallclock.
Is there any description of those relations?

I don't seem to find any other MSR referencing the TscFreqSel bit in
HWCR on the AMD Open-Source Register Reference, but I might be looking
at the wrong place.

Thanks, Roger.

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