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SubjectRe: [PATCH v2] tpm_tis: Remove the HID IFX0102
On Mon, Jul 06, 2020 at 05:00:51PM +0300, Jarkko Sakkinen wrote:
> On Mon, Jul 06, 2020 at 11:46:46AM +0000, Peter.Huewe@infineon.com wrote:
> > 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.
>
> Peter,
>
> Looking at dmesg:
>
> 1. tmp_infineon initializes cleanly
> 2. tpm_tis fails misserably with bunch error messages
>
> I'm cool with reverting the patch though. Please send a revert patch and
> explain this in the commit message because right now what you are saying
> is completely undocumented.
>
> Also, this tpm_infineon issue needs to be fixed properly after the
> revert.
>
> The bugzilla bug is unrelated to this issue but it causes extra harm
> fixing any bugs and confusion among the users as the bug discussions
> proves.
>
> How do we get the quirks for tpm_tis and tpm_infineon so that they can
> separate each other?

Also in the revert commit, please add a comment to tpm_tis.c
about the existing conflict, e.g.

/*
* Legacy Infineon devices can emit illegit warnings as tpm_tis and
* tpm_infineon have a conflicting device ID IFX0102.
*/

I'm cool reverting it as long as I get a patch with the required
premises to do so and proper documentation, because the issue is
still real.

/Jarkko

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