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

From: Jerry Snitselaar <jsnitsel@redhat.com>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Christian Bundy <christianbundy@fraction.io>,
	Peter Huewe <peterhuewe@gmx.de>, Jason Gunthorpe <jgg@ziepe.ca>,
	Stefan Berger <stefanb@linux.vnet.ibm.com>,
	stable <stable@vger.kernel.org>,
	linux-integrity@vger.kernel.org
Subject: Re: [PATCH v2] tpm_tis: reserve chip for duration of tpm_tis_core_init
Date: Tue, 17 Dec 2019 10:26:12 -0700	[thread overview]
Message-ID: <20191217172612.5hxyt7w3wtbrkypm@cantor> (raw)
In-Reply-To: <20191217171844.huqlj5csr262zkkk@cantor>

On Tue Dec 17 19, Jerry Snitselaar wrote:
>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.
>

It appears he is out of the office until January, so I doubt I will hear
anything back until then.

>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