Re: [BUG] tpm_crb/Intel PTT: Late S3/S5/Reboot ACPI power management deadlock

[Jarkko Sakkinen <jarkko@kernel.org>]

On Mon, Oct 19, 2026 at 03:05:42AM -0400, Sean Meadows wrote:
> 
> On 10/10/26 15:39, Jarkko Sakkinen wrote:
> > 
> > So the gist why I believe that this might have effect is that every
> > transmit reverts the state to the initial state. That should erase any
> > weird state that firmware might be in (usually not that great quality
> > code).
> > 
> > I think Mario's patch is good overall for the stability. It looks to me
> > that we are catching some weird state inside firmware where we don't
> > have direct visibility. Or this is my guess at least.
> > 
> > Br, Jarkko
> 
> 7.3.0-rc6-g587527648af0 with cherry-pick
> 9154aa6c4b789d23e59d599c330cab2c4e915401
> 
> strings /lib/modules/$(uname -r)/build/vmlinux | grep "cmd_ready"
> Used to validate crb_cmd_ready responses.
> 
> The patch failed at 201 hours, on the ninth drop into S3. While this
> represents an all-time high for uptime, the failure demonstrates that
> the Intel PTT can still enter a corrupt state.
> 
> Where do we go from here?

I don't know. I'd even consider finding the channel to report the
possible firmware bug to Intel.

I don't have resources to do this but getting Windows CRB register
state captured could help. And then writing perhaps bpftrace script
to dump the live register state of tpm_crb (because you should
never trust reading code when you measure).

> 
> Sean

Br, Jarkko