On Tue, Feb 10, 2015 at 07:16:32AM -0500, Stefan Berger wrote: > On 02/09/2015 03:39 AM, Jarkko Sakkinen wrote: > >On Mon, Feb 09, 2015 at 12:08:46AM +0100, Peter Hüwe wrote: > >>Am Mittwoch, 4. Februar 2015, 15:21:09 schrieb Jarkko Sakkinen: > >>>If during transmission system error was returned, the logic was to > >>>incorrectly deduce that chip is a TPM 1.x chip. This patch fixes this > >>>issue. Also, this patch changes probing so that message tag is used as the > >>>measure for TPM 2.x, which should be much more stable. > >>Is it aware that some TPMs may respond with 0x00C1 as TAG for TPM1.2 commands? > >I guess none of the TPM 1.2 command answer with the tag 0x8002? > > > FYI: pdf page 26 , section 6.1 explains the predictable return value for a > TPM1.2 command seen by a TPM2 > > http://www.trustedcomputinggroup.org/files/static_page_files/8C68ADA8-1A4B-B294-D0FC06D3773F7DAA/TPM%20Rev%202.0%20Part%203%20-%20Commands%2001.16-code.pdf > > Following this: > > Sending a TPM1.2 command to a TPM2 should return a TPM1.2 header (tag = > 0xc4) and error code (TPM_BADTAG = 0x1e) > > Sending a TPM 2 command to a TPM 2 will give a TPM 2 tag in the header. > Sending a TPM 2 command to a TPM 1.2 will give a TPM 1.2 tag in the header > and an error code. Thank you for the information. Do you think that for some reason tpm2_probe() shoould instead check that value is not this error instead of checking that tag is 0x80002? > Stefan /Jarkko -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
