RE: [PATCH v2] tpm_tis: Remove the HID IFX0102

From: Peter.Huewe
Date: Mon Jul 06 2020 - 07:47:58 EST


Hi,
NACK

> % git --no-pager grep IFX0102 drivers/char/tpm
> drivers/char/tpm/tpm_infineon.c: {"IFX0102", 0},
> drivers/char/tpm/tpm_tis.c: {"IFX0102", 0}, /* Infineon */
> Obviously IFX0102 was added to the HID table for the TCG TIS driver by mistake.

The HID IFX0102 was NOT added by mistake.
Let me explain the history a bit:

Old SLB 9635 / 9630 TPMs had two ways to interface them
- proprietary 'io' mapped protocol (tpm_infineon)
- tis protocol (tpm_tis)

Both match the same HID.
However with the emerging of the tis protocol, the io protocol eventually went away for newer products.
So all TPM1.2 by IFX match the HID0102 and the TCG generic ones PNP0C31

So basically you break TPM1.2 support for all (newer) Infineon chips if the platform vendor used the IFX0102 HID as they would speak via tpm_infineon driver.
The bug must be something different, especially as it only seems to happen after suspend resume.


Thanks,
Peter