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Date:   Thu, 29 Aug 2019 13:25:27 -0700
From:   Jerry Snitselaar <jsnitsel@redhat.com>
To:     Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Cc:     linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
        Peter Huewe <peterhuewe@gmx.de>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        Alexey Klimov <aklimov@redhat.com>
Subject: Re: [PATCH 2/2 v2] tpm_tis: override durations for STM tpm with
 firmware 1.2.8.28
Message-ID: <20190829202527.auyqek7yryuvaruk@cantor>
Reply-To: Jerry Snitselaar <jsnitsel@redhat.com>
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        linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
        Peter Huewe <peterhuewe@gmx.de>, Jason Gunthorpe <jgg@ziepe.ca>,
        Alexey Klimov <aklimov@redhat.com>
References: <20190828004621.29050-1-jsnitsel@redhat.com>
 <20190828004621.29050-3-jsnitsel@redhat.com>
 <20190829144002.zhuqxnsswgl65pnm@linux.intel.com>
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On Thu Aug 29 19, Jarkko Sakkinen wrote:
>On Tue, Aug 27, 2019 at 05:46:21PM -0700, Jerry Snitselaar wrote:
>> There was revealed a bug in the STM TPM chipset used in Dell R415s.
>> Bug is observed so far only on chipset firmware 1.2.8.28
>> (1.2 TPM, device-id 0x0, rev-id 78). After some number of
>> operations chipset hangs and stays in inconsistent state:
>>
>> tpm_tis 00:09: Operation Timed out
>> tpm_tis 00:09: tpm_transmit: tpm_send: error -5
>>
>> Durations returned by the chip are the same like on other
>> firmware revisions but apparently with specifically 1.2.8.28 fw
>> durations should be reset to 2 minutes to enable tpm chip work
>> properly. No working way of updating firmware was found.
>>
>> This patch adds implementation of ->update_durations method
>> that matches only STM devices with specific firmware version.
>>
>> Cc: Peter Huewe <peterhuewe@gmx.de>
>> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
>> Cc: Jason Gunthorpe <jgg@ziepe.ca>
>> Signed-off-by: Alexey Klimov <aklimov@redhat.com>
>> Signed-off-by: Jerry Snitselaar <jsnitsel@redhat.com>
>> ---
>> v2: Make suggested changes from Jarkko
>>     - change struct field name to durations from durs
>>     - formatting cleanups
>>     - turn into void function like update_timeouts and
>>       use chip->duration_adjusted to track whether adjustment occurred.
>
>The code repetition looks horrible so I wrote a patch that should help:
>
>https://patchwork.kernel.org/patch/11121475/
>
>Read the remar that prepends the diffstat.
>
>/Jarkko

LGTM, and testing it on a 1.2 tpm system here worked fine. You can add my
Reviewed-by and Tested-by.

I have reworked this 2/2 patch to make use of these new structs and
pull the tpm1_getcap calls out of the for loop. So I will submit a v3
to go on top of your patch.