Re: [PATCH v3 2/2] usb: misc: xapea00x: perform platform initialization of TPM

On Tue, May 8, 2018 at 5:47 AM, Jarkko Sakkinen
[off-list ref] wrote:

On Fri, May 04, 2018 at 08:00:22AM -0500, David R. Bild wrote:

quoted

Normally the system platform (i.e., BIOS/UEFI for x86) is responsible
for performing initialization of the TPM.  For these modules, the host
kernel is the platform, so we perform the initialization in the driver
before registering the TPM with the kernel TPM subsystem.

The initialization consists of issuing the TPM startup command,
running the TPM self-test, and setting the TPM platform hierarchy
authorization to a random, unsaved value so that it can never be used
after the driver has loaded.

Signed-off-by: David R. Bild <redacted>

Have you checked what the TPM driver already does?

Yes.  It does the startup and self-test.

 However, this driver sets the platform hierarchy password *before*
giving the TPM to the TPM driver (thus, before the TPM driver can do
the startup and self-test).  Startup and self-test are prerequisites
for setting the platform hierarchy password, so this driver does those
itself too.

Best,
David