Re: REGRESSION WITH BISECT: v6.5-rc6 TPM patch breaks S3 on some Intel systems

[Jarkko Sakkinen]

On Fri Aug 18, 2023 at 4:58 AM EEST, Limonciello, Mario wrote:
>
>
> On 8/17/2023 5:33 PM, Jarkko Sakkinen wrote:
> > On Fri Aug 18, 2023 at 1:25 AM EEST, Todd Brandt wrote:
> >> On Fri, 2023-08-18 at 00:47 +0300, Jarkko Sakkinen wrote:
> >>> On Fri Aug 18, 2023 at 12:09 AM EEST, Todd Brandt wrote:
> >>>> While testing S3 on 6.5.0-rc6 we've found that 5 systems are seeing
> >>>> a
> >>>> crash and reboot situation when S3 suspend is initiated. To
> >>>> reproduce
> >>>> it, this call is all that's required "sudo sleepgraph -m mem
> >>>> -rtcwake
> >>>> 15".
> >>>
> >>> 1. Are there logs available?
> >>> 2. Is this the test case: https://pypi.org/project/sleepgraph/ (never
> >>> used it before).
> >>
> >> There are no dmesg logs because the S3 crash wipes them out. Sleepgraph
> >> isn't actually necessary to activate it, just an S3 suspend "echo mem >
> >> /sys/power/state".
> >>
> >> So far it appears to only have affected test systems, not production
> >> hardware, and none of them have TPM chips, so I'm beginning to wonder
> >> if this patch just inadvertently activated a bug somewhere else in the
> >> kernel that happens to affect test hardware.
> >>
> >> I'll continue to debug it, this isn't an emergency as so far I haven't
> >> seen it in production hardware.
> > 
> > OK, I'll still see if I could reproduce it just in case.
> > 
> > BR, Jarkko
>
> I'd like to better understand what kind of TPM initialization path has 
> run.  Does the machine have some sort of TPM that failed to fully 
> initialize perhaps?
>
> If you can't share a full bootup dmesg, can you at least share
>
> # dmesg | grep -i tpm

It would be more useful perhaps to get full dmesg output after power on
and before going into suspend.

Also ftrace filter could be added to the kernel command-line:

ftrace=function ftrace_filter=tpm*

After bootup:

mount -t tracefs nodev /sys/kernel/tracing
cat /sys/kernel/tracing/trace

BR, Jarkko