[U-Boot] [PATCH] TPM: remove dead code

[Simon Glass]

Hi Wolfgang,

On Thu, Nov 22, 2012 at 11:10 AM, Simon Glass <sjg at chromium.org> wrote:
> Hi Wolfgang,
>
> On Mon, Nov 19, 2012 at 11:14 PM, Wolfgang Denk <wd at denx.de> wrote:
>> Dear Tom,
>>
>> In message <1351960246-31771-1-git-send-email-wd at denx.de> you wrote:
>>> The TPM code was added more than a year or 4 releases ago.  This was
>>> done under the proposition that board support that would actually use
>>> such code would be added soon.  However, nothing happened since.  The
>>> code has no users in mainline, and does not even get build for any
>>> configuration, so we cannot even tell if it compiles at all.
>>>
>>> Remove the unused code.  In in some far future actual users show up,
>>> it can be re-added easily.
>>>
>>> Signed-off-by: Wolfgang Denk <wd at denx.de>
>>> Cc: Vadim Bendebury <vbendeb at chromium.org>
>>> Cc: Simon Glass <sjg at chromium.org>
>>> ---
>>>  README                        |  10 -
>>>  common/Makefile               |   1 -
>>>  common/cmd_tpm.c              | 103 ---------
>>>  doc/driver-model/UDM-tpm.txt  |  48 ----
>>>  drivers/tpm/Makefile          |  43 ----
>>>  drivers/tpm/generic_lpc_tpm.c | 495 ------------------------------------------
>>>  include/tpm.h                 |  71 ------
>>>  7 files changed, 771 deletions(-)
>>>  delete mode 100644 common/cmd_tpm.c
>>>  delete mode 100644 doc/driver-model/UDM-tpm.txt
>>>  delete mode 100644 drivers/tpm/Makefile
>>>  delete mode 100644 drivers/tpm/generic_lpc_tpm.c
>>>  delete mode 100644 include/tpm.h
>>
>> This was sent before end of the merge window, but has not been applied
>> yet.
>>
>> Despite some discussion about why having TPM code is generally useful,
>> there are still no actual users for it visible, so I really would like
>> to see this patch applied.
>>
>> It is trivial to re-activate this code if actual users for it should
>> be added some day to come.
>
> For what it is worth, this is a NAK from me. There is a patch pending
> for the next release to enable this for coreboot, and another driver
> for an i2c TPM driver for the ARM Chromebook also pending, also within
> the merge window. The TPM support here is light but it is a start, and
> reverting it seems to serve no purpose (I am happy to maintain the
> code if it needs work, e.g. for device model). On the contrary this
> code provides a base on which verified boot can be built, and provides
> useful functions for talking to a TPM which may be on others boards as
> well.

Part of the reason why the TPM was never turned on in coreboot was the
difficulty in upstreaming the code, which resulted in us giving up
about a year ago. That effort has since restarted and I am hopeful
that it will be successful.

Perhaps as a compromise we could have one more cycle to create a
verified boot which uses the TPM drivers, which I think is what is
required here? The timing is good at this end to actually do the work.

That would send that right signal that this work is valued upstream.
That is a very important signal.

Regards,
SImon

>
> Regards,
> Simon
>
>>
>> Best regards,
>>
>> Wolfgang Denk
>>
>> --
>> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
>> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
>> Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd at denx.de
>> "I used to think that the brain was the most wonderful  organ  in  my
>> body. Then I realized who was telling me this."        - Emo Phillips