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Subject: Re: tpm_tis TPM2.0 not detected on cold boot
From:   Mimi Zohar <zohar@linux.ibm.com>
To:     Michael =?ISO-8859-1?Q?Niew=F6hner?= <linux@mniewoehner.de>,
        Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
        James Bottomley <James.Bottomley@HansenPartnership.com>,
        peterhuewe@gmx.de, jgg@ziepe.ca, arnd@arndb.de,
        linux-integrity@vger.kernel.org,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Nayna Jain <nayna@linux.ibm.com>,
        Ken Goldman <kgold@linux.ibm.com>
Date:   Sat, 22 Dec 2018 17:53:52 -0500
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         <1f281756bb1f041e55be8dd090670a1a7b1d1c94.camel@mniewoehner.de>
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On Sat, 2018-12-22 at 14:47 +0100, Michael Niewöhner wrote:

> When I remove the timeout and boot directly to the linux kernel, I get that
> "2314 TPM-self test error" since it has not finished, yet. The TPM is detected
> by IMA and works fine then.
> 
> Some more tests showed that any delay before booting the kernel causes the TPM
> to not get detected. I tested, 10, 15, 20, 30, 60... seconds. Only in some very
> rare cases the TPM got detected.
> 
> I wanted to know if the TPM is in an well initialized state at the time of that
> error. Since I was not able to get some test/debug kernel patches working I
> decided to try kexec. It turned out that the TPM is indeed correctly working and
> will be detected just fine by linux after kexec!

No surprise here.  kexec would be the equivalent of a soft reboot.

> 
> Is there anyone having an idea what could be wrong here? I am willing to debug
> this but I have really no idea where to start :-(

A while ago, I was "playing" with a pi.  Commenting out
tpm2_do_selftest() seemed to resolve a similar problem, but that was
before James' patches.  I don't know if that would make a difference
now.

Mimi