RE: [tpmdd-devel] [PATCH] TPM: Retry SaveState command in suspendpath

From: Peter.Huewe
Date: Mon Mar 18 2013 - 05:06:37 EST


> The TPM is too busy to respond to the command immediately, but the
> command could be resubmitted at a later time. The TPM MAY return
> TPM_RETRY for any command at any time.

> It can take several seconds before the TPM will respond again. I measured a typical time between 3 and 4 seconds and the timeout is set at a safe 5 seconds.
> I tested a variety of TPMs from Infineon, Nuvoton, Atmel, and STMicro but was only able to reproduce this with LPC and I2C TPMs from Infineon.

Yes, our TPMs respond with TPM_RETRY if the time between two TPM_SaveState is too short to prevent wear leveling.
If I remember correctly the internal timer is set to 5sec.

As you've already said this is compliant with the TCG specification.

the patch looks good to me.

Reviewed-by: Peter Huewe <peter.huewe@xxxxxxxxxxxx>
Acked-by: Peter Huewe <peter.huewe@xxxxxxxxxxxx>


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at