Re: [PATCH v4 2/2] tpm: add support for partial reads

From: Tadeusz Struk
Date: Mon Nov 19 2018 - 11:44:58 EST


On 11/19/18 5:58 AM, Jarkko Sakkinen wrote:
> Please explain a scenario where "!ret_size" would no work given that
> both size and partial_data have always positive value?

Right, I only looked at the one line above before responding.
I'll change it to !ret_size

>
> I don't understand. In order to maintain backwards compatibility you can
> send a new command at any time.

No, currently it is not possible to send a new command until the previous
response is consumed. -EBUSY is returned if one sends a new command before
reading the previous response (or at least part of it). See:
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/char/tpm/tpm-dev-common.c#n128

--
Tadeusz