Re: [tpmdd-devel] [PATCH v2] tpm: Apply a sane minimum adapterlimit value for retransmission.

From: Enric Balletbo i Serra
Date: Thu Mar 02 2017 - 15:37:33 EST


Hi Andrew,

On 02/03/17 18:24, Andrew Lunn wrote:
>>>> Hi Enric
>>>>
>>>> Maybe you should remember that you need to use smaller transfers? If
>>>> you don't remember, but use the full size message every time and only
>>>> drop back on error, the i2c core is going to log rate limited
>>>> messages. By remembering, there will only be one such message in the
>>>> log.
>>>>
>>
>
>> Maybe I did not explain well but this is what the code does, when
>> i2c-core fails with -EOPNOTSUPP because the msg is too long for this
>> adapter it loop with a smaller chunk of fixed size, so you only see
>> the i2c-core message once.
>
> Hi Enric
>
> Would it not be more accurate to say, that you only see the i2c-core
> message once, for this transfer request. Is the next transfer request
> again going to use the longer length? then fail, maybe generate
> another i2c core message, depending on rate limiting, and then use the
> lower message size? I think it does.
>
> Which is why i suggested remembering the length.
>

Ah ok, sorry I did not understand you, got it now. Yes, so with this every time you do, i.e. a tpm_getpubek, you will see the i2c-core message, right. Thanks. Sounds a good suggestion for me.

Cheers,
Enric

> Andrew
>