You should be able to ignore that. But I am unsure of what is leading you to that state. Is someone
Sending a selftest command before a startup command? The startup command, when not in field upgrade
Mode, should be startup. So when the tpm initializes, it expects one of the first commands as described
In the spec:
https://trustedcomputinggroup.org/wp-content/uploads/TPM-Rev-2.0-Part-1-Architecture-01.38.pdf

The first command sent to the tpm should be a startup command..... you can see that in Figure 5 on page 57
Of the spec above and described in detail in section 12.2.2

Bill

> -----Original Message-----
> From: tpm2 [mailto:tpm2-bounces(a)lists.01.org] On Behalf Of Gael GUEGAN
> Sent: Thursday, August 8, 2019 3:35 AM
> To: tpm2(a)lists.01.org; javierm(a)redhat.com
> Subject: [tpm2] [tpm2-driver] Error at boot : A TPM error (256) occurred continue
> selftest
> 
> Hello all,
> 
> 
> 
> I am working with the linux kernel version 4.9 on an embedded target.
> 
> And I am having the following error message from the TPM driver at boot :
> 
> 
> 
> > $  dmesg | grep TPM
> 
> [    2.946137] tpm_tis_spi spi32766.0: 2.0 TPM (device-id 0x0, rev-id 78)
> 
> [    2.975824] tpm tpm0: A TPM error (256) occurred continue selftest
> 
> 
> 
> So I have seen that this error 256 correspond to TPM2_RC_INITIALIZE = 0x0100,
> and that it is thrown  from this function
> <https://github.com/torvalds/linux/blob/v4.9/drivers/char/tpm/tpm-
> interface.c#L422>  (be32_to_cpu() when executing a tpm_transmit_cmd()).
> 
> 
> 
> However can someone explain why I am having this error ? Is it possible that it is
> because I am trying to access to the TPM during its initialization phase / selftest
> phase ?
> 
> Can I ignore this error without worry ?
> 
> 
> 
> 
> 
> Thank for your help,
> 
> 
> 
> 
> 
> Gael GUEGAN