Re: Atmel I2C TPM transfer length issues

[Andrew Lunn <andrew-g2DYL2Zd6BY@public.gmane.org>]

> Just limit the value which get_burstcount() returns to 256.
>
> This should do the trick - because that would be the mechanism the
> tpm itself would use to fragment its response.  Atleast for other
> tpms like our infineon slb9645 i2c tpm that would work.

Yes, that was one idea i had. But then i found the comment on the top
of tpm_i2c_atmel:

 * Teddy Reed determined the basic I2C command flow, unlike other I2C TPM
 * devices the raw TCG formatted TPM command data is written via I2C and then
 * raw TCG formatted TPM command data is returned via I2C.

The driver does not do anything like read the burst size and then
transfer in blocks. It reads/writes all in one go.

However, you have answered what was going to be a follow question. The
hardware is not yet set in stone. We could change the TPM. Use the
Infinion TPM with a modified get_burstcount(). And you think this will
work. Great.

Thanks
	Andrew

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