Re: [PATCH 1/2] tpm: Factor out common startup code

On Mon, Jun 20, 2016 at 03:07:57PM -0600, Jason Gunthorpe wrote:

On Sun, Jun 19, 2016 at 02:39:24PM +0200, Jarkko Sakkinen wrote:

quoted

quoted

Signed-off-by: Jason Gunthorpe <jgunthorpe-ePGOBjL8dl3ta4EC/59zMFaTQe2KTcn/@public.gmane.org>
Tested-by: Andrew Zamansky <redacted>

Couldn't tpm?_auto_startup() be static functions inside tpm-chip.c?

Why? tpm-chip is for chip functions and tpm-interface is for command
issuing functions, the startup command sequencors seem appropriately
placed...

These are still module private functions.

Hmm.. interesting point and I actually realized that this related to
work that I'm doing right now.

I'm working on a patches to move TPM 1.x protocol level code to
tpm1-cmd.c. We want to do so that one can conditionally compile out TPM
1.x when it is not needed. Another reason is that, I would not like to
put TPM 1.x sealing code to tpm-interface.c.

Given that I think it is cool to keep these in tpm-interface.c in this
in tpm-interface.c.

Summary: lets keep it in a way that these functions are in
tpm-interface.c for now.

quoted

quoted

+enum TPM_OPS_FLAGS {
+	TPM_OPS_PROBE_TPM2 = BIT(0),

I see two alternatives here:

1. Make this work for tpm_tis.c if it is doable.
2. Remove this flag and call tpm2_probe() inside tpm_i2c_nuvoton.c.

If this flag works only for a single driver, it does not bring any value.

We already have two drivers that auto probe, you don't think there
will be more? The idea is to try and remove these low level entry
points so drivers are simpler.

TIS doesn't use it because it needs to get things setup in advance for
interrupt auto-probing, which is a very TIS unique thing.

Alternatively we can drop the auto-probe from nuvoton and force it to
rely on compatible string matching to enter TPM2 mode.

The patch set used TPM2_OPS_PROBE_TPM2 only for nuvoton driver. The more
recent one used it incorrectly with tpm_tis.

Jason

PS. Would you have time to look at https://lkml.org/lkml/2016/6/17/887
and give your feedback? :)

/Jarkko

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