Re: [PATCH] tpm_i2c_atmel: fix i2c_atmel_recv() when response is greater than 35 bytes

[Jarkko Sakkinen <jarkko.sakkinen-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>]

On Tue, Nov 22, 2016 at 02:47:37PM -0300, Fábio Urquiza wrote:
> On Tue, Nov 22, 2016 at 2:08 PM, Jason Gunthorpe
> <jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org> wrote:
> >
> > On Tue, Nov 22, 2016 at 09:40:07AM -0300, Fabio Urquiza wrote:
> > > If the variable expected_len is greater than 35 bytes, i2c_atmel_recv()
> > > ignores the amount of data already read in i2c_atmel_read_status() and
> > > request more data than what the device is ready to supply. As result the
> > > TPM data sent to the upper layers will miss the first 35 bytes of the
> > > response and will be filled with garbage in the end.
> >
> > I'm concerned your chip is not behaving the same as mine, I have to
> > dig out my hardware and check. I'm fairly certain I would have hit
> > this..
> >
> > Do you know the revision code for your chip?
> >
> > IIRC my TPM re-read the message starting from byte 0, which is why the
> > code is like this.
> >
> > Jason
> 
> I'm working on an emulator for that chip and I don't have the real
> hardware to check.
> 
> That behavior makes sense. I will change the emulator to follow that.
> 
> You can ignore that patch, then.
> 
> Thanks,
> 
> -Fabio Urquiza

Thanks guys. I was going to ask if someone is able to test this. Good
that you sorted this out.

/Jarkko

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