Re: [tpmdd-devel] [PATCH 1/2] tpm: Apply an adapterlimit for retransmission.

From: Enric Balletbo i Serra
Date: Wed Feb 22 2017 - 06:16:23 EST


Hi Andrew,

Removing Bryan Freed from the loop as seems his email is not valid anymore. I already CC'ied Andrey which is doing the TPM bit in chromeos kernel.

On 21/02/17 17:29, Andrew Lunn wrote:
> On Tue, Feb 21, 2017 at 03:44:59PM +0100, Enric Balletbo i Serra wrote:
>> From: Bryan Freed <bfreed@xxxxxxxxxxxx>
>>
>> When the I2C Infineon part is attached to an I2C adapter that imposes
>> a size limitation, large requests will fail -EINVAL.
>> Retry them with size backoff without re-issuing the 0x05 command
>> as this appears to occasionally put the TPM in a bad state.
>
> Hi Enric
>
> Rather than trying small and smaller transfers, would it not be better
> to get the i2c core to expose the quirk info about transfer limits?
>

Sounds a good idea to me, I guess the quirk info can be accessed with

tpm_dev.client->adapter->quirks->max_read_len

so I think we don't need to touch the i2c core. I'll propose a second version of the patch.

Thanks,
Enric


> Andrew
>