On 07.05.22 21:43, Jarkko Sakkinen wrote:
> On Fri, May 06, 2022 at 02:31:48PM +0200, Stefan Mahnke-Hartmann wrote:
>> TPM2_GetCapability with a capability that has the property type value
>> of TPM_PT_TOTAL_COMMANDS returns a zero length list, when an Infineon
>> TPM2 is in Field Upgrade mode.
>> Since an Infineon TPM2.0 in Field Upgrade mode returns RC_SUCCESS on
>> TPM2_Startup, the Field Upgrade mode has to be detected by
>> TPM2_GetCapability.
>>
>> Signed-off-by: Stefan Mahnke-Hartmann <stefan.mahnke-hartmann@xxxxxxxxxxxx>
>> ---
>> drivers/char/tpm/tpm2-cmd.c | 6 ++++++
>> 1 file changed, 6 insertions(+)
>>
>> diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
>> index e62a644ce26b..659130e2936e 100644
>> --- a/drivers/char/tpm/tpm2-cmd.c
>> +++ b/drivers/char/tpm/tpm2-cmd.c
>> @@ -746,6 +746,12 @@ int tpm2_auto_startup(struct tpm_chip *chip)
>> }
>>
>> rc = tpm2_get_cc_attrs_tbl(chip);
>> + /*
>> + * Infineon TPM in Field Upgrade mode will return no data for the number
>> + * of supported commands.
>> + */
>> + if (rc == -ENODATA)
>> + rc = TPM2_RC_UPGRADE;
>
> Injecting hardware error codes like this is not considered a great idea.
Resetting the error code was to avoid code duplication, while following the
same rationale as Mårten's patch. I can also add the -ENODATA to the if clause
below or duplicate the code block (similar to Mårten's). Do you have a better
suggestion?
>
>>
>> out:
>> if (rc == TPM2_RC_UPGRADE) {
>> --
>> 2.25.1
>>
>
> BR, Jarkko
