Re: [PATCH v2 0/3] tpm_tis: Clean up force module parameter

[Jason Gunthorpe <jgunthorpe@obsidianresearch.com>]

On Tue, Dec 01, 2015 at 11:33:51PM +0200, Jarkko Sakkinen wrote:
> On Tue, Dec 01, 2015 at 11:58:26AM -0700, Jason Gunthorpe wrote:

> I went through the patches and didn't see anything that would shock me
> enough not to apply the patches in the current if they also work when
> tested *but* are these release critical for Linux v4.4?

Jarkko,

Can you explain how

commit 399235dc6e95400a1322a9999e92073bc572f0c8
Author: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Date:   Tue Sep 29 00:32:19 2015 +0300

    tpm, tpm_tis: fix tpm_tis ACPI detection issue with TPM 2.0

Is supposed to work? I get the jist of the idea, but I'm not seeing
how it can work reliably..

The idea is to pass off TPM2_START_FIFO to tpm_tis?

I'm guessing that if the driver probe order is tpm_crb,tpm_tis then
things work because tpm_crb will claim the device first? Otherwise
tpm_tis claims these things unconditionally? If the probe order is
reversed things become broken?

What is the address tpm_tis should be using? I see two things, it
either uses the x86 default address or it expects the ACPI to have a
MEM resource. AFAIK ACPI should never rely on hard wired addresses, so
I removed that code in this series. Perhaps tpm_tis should be using
control_area_pa ? Will ACPI ever present a struct resource? (if yes,
why isn't tpm_crb using one?)

There is also something wrong with the endianness in the acpi
stuff. I don't see endianness conversions in other acpi places, so I
wonder if the ones in tpm_crb are correct. If they are correct then
the struct needs le/be notations and there are some missing
conversions.

Jason