Re: [PATCH v10 8/8] tpm: TPM 2.0 FIFO Interface

[Stefan Berger]

On 12/12/2014 02:46 PM, Jarkko Sakkinen wrote:
> Detect TPM 2.0 by sending idempotent TPM 2.x command. Ordinals for
> TPM 2.0 are higher than TPM 1.x commands so this should be fail-safe.
> Using STS3 is unreliable because some chips just report 0xff and not
> what the spec says.

TPM TIS 1.2 can report either 0xff or 0x00 for sts3 since that part of 
register was not defined for this version but only for a later version. 
So, unless the TIS 1.3 for TPM 2.0 is broken, it should report a bit 
_pattern_ (not plain 0x00 or 0xff) that you could apply the suggested 
mask to and check then.

    Stefan

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