Re: [PATCH v2] tpm_tis: reserve chip for duration of tpm_tis_core_init

Jerry Snitselaar
2019-12-17T17:18:53Z

On Tue Dec 17 19, Jarkko Sakkinen wrote:
>On Mon, 2019-12-16 at 18:14 -0800, Dan Williams wrote:
>> On Mon, Dec 16, 2019 at 6:00 PM Jerry Snitselaar <jsnitsel@redhat.com> wrote:
>> > On Mon Dec 16 19, Dan Williams wrote:
>> > > On Mon, Dec 16, 2019 at 4:59 PM Jarkko Sakkinen
>> > > <jarkko.sakkinen@linux.intel.com> wrote:
>> > > > On Wed, 2019-12-11 at 16:54 -0700, Jerry Snitselaar wrote:
>> > > > > Instead of repeatedly calling tpm_chip_start/tpm_chip_stop when
>> > > > > issuing commands to the tpm during initialization, just reserve the
>> > > > > chip after wait_startup, and release it when we are ready to call
>> > > > > tpm_chip_register.
>> > > > >
>> > > > > Cc: Christian Bundy <christianbundy@fraction.io>
>> > > > > Cc: Dan Williams <dan.j.williams@intel.com>
>> > > > > Cc: Peter Huewe <peterhuewe@gmx.de>
>> > > > > Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
>> > > > > Cc: Jason Gunthorpe <jgg@ziepe.ca>
>> > > > > Cc: Stefan Berger <stefanb@linux.vnet.ibm.com>
>> > > > > Cc: stable@vger.kernel.org
>> > > > > Cc: linux-integrity@vger.kernel.org
>> > > > > Fixes: a3fbfae82b4c ("tpm: take TPM chip power gating out of tpm_transmit()")
>> > > > > Fixes: 5b359c7c4372 ("tpm_tis_core: Turn on the TPM before probing IRQ's")
>> > > > > Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
>> > > >
>> > > > I pushed to my master with minor tweaks and added my tags.
>> > > >
>> > > > Please check before I put it to linux-next.
>> > >
>> > > I don't see it yet here:
>> > >
>> > > http://git.infradead.org/users/jjs/linux-tpmdd.git/shortlog/refs/heads/master
>> > >
>> > > However, I wanted to make sure you captured that this does *not* fix
>> > > the interrupt issue. I.e. make sure you remove the "Fixes:
>> > > 5b359c7c4372 ("tpm_tis_core: Turn on the TPM before probing IRQ's")"
>> > > tag.
>> > >
>> > > With that said, are you going to include the revert of:
>> > >
>> > > 1ea32c83c699 tpm_tis_core: Set TPM_CHIP_FLAG_IRQ before probing for interrupts
>> >
>> > Dan, with the above reverted do you still get the screaming interrupt?
>>
>> Yes, the screaming interrupt goes away, although it is replaced by
>> these messages when the driver starts:
>>
>> [ 3.725131] tpm_tis IFX0740:00: 2.0 TPM (device-id 0x1B, rev-id 16)
>> [ 3.725358] tpm tpm0: tpm_try_transmit: send(): error -5
>> [ 3.725359] tpm tpm0: [Firmware Bug]: TPM interrupt not working,
>> polling instead
>>
>> If the choice is "error message + polled-mode" vs "pinning a cpu with
>> interrupts" I'd accept the former, but wanted Jarkko with his
>> maintainer hat to weigh in.
>>
>> Is there a simple sanity check I can run to see if the TPM is still
>> operational in this state?
>
>What about T490S?
>
>/Jarkko
>

Hi Jarkko, I'm waiting to hear back from the t490s user, but I imagine
it still has the problem as well.

Christian, were you able to try this patch and verify it still
resolves the issue you were having with the kernel failing to get the
timeouts and durations from the tpm?

Thanks,
Jerry