Subject: Re: spurious mce Hardware Error messages in next-20250912

From: Yazen Ghannam <[email-masked]>
Date: Thu, 18 Sep 2025 17:14:05 -0400

On Thu, Sep 18, 2025 at 09:04:53PM +0000, Luck, Tony wrote:
> > For the current issue, it does seem that the registers contain junk
> > values. And we are only now seeing this with the recent rework.
> 
> Do you try to clear these registers after logging? Or just rely on clearing
> the MCi_STATUS register?
> 

Yes, the MCA_DESTAT register is cleared in a couple of places depending
on the scenario.

> If you are clearing, then it isn't working (or new junk values appear quickly).

Right, and MCi_STATUS has junk values in some of the affected banks.
They just happen to be ignored because they don't have the Valid bit
set.

And MCi_STATUS is cleared at Linux init time, so the junk values stick
or come back by the time Bert ran the script.

Thanks,
Yazen