From: Alexander Steffen <Alexander.Steffen@infineon.com>
To: Stephen Boyd <swboyd@chromium.org>,
Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
Peter Huewe <peterhuewe@gmx.de>
Cc: Andrey Pronin <apronin@chromium.org>,
<linux-kernel@vger.kernel.org>, Jason Gunthorpe <jgg@ziepe.ca>,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
<linux-integrity@vger.kernel.org>,
Duncan Laurie <dlaurie@chromium.org>,
Guenter Roeck <groeck@chromium.org>
Subject: Re: [PATCH v2 5/6] tpm: add driver for cr50 on SPI
Date: Fri, 19 Jul 2019 09:53:00 +0200 [thread overview]
Message-ID: <1bb8d417-3199-7aff-ad60-b25464502cb3@infineon.com> (raw)
In-Reply-To: <5d30b649.1c69fb81.f440e.9a0a@mx.google.com>
On 18.07.2019 20:11, Stephen Boyd wrote:
> Quoting Alexander Steffen (2019-07-18 09:47:22)
>> On 17.07.2019 23:38, Stephen Boyd wrote:
>>> Quoting Stephen Boyd (2019-07-17 12:57:34)
>>>> Quoting Alexander Steffen (2019-07-17 05:00:06)
>>>>>
>>>>> Can't the code be shared more explicitly, e.g. by cr50_spi wrapping
>>>>> tpm_tis_spi, so that it can intercept the calls, execute the additional
>>>>> actions (like waking up the device), but then let tpm_tis_spi do the
>>>>> common work?
>>>>>
>>>>
>>>> I suppose the read{16,32} and write32 functions could be reused. I'm not
>>>> sure how great it will be if we combine these two drivers, but I can
>>>> give it a try today and see how it looks.
>>>>
>>>
>>> Here's the patch. I haven't tested it besides compile testing.
>
> The code seems to work but I haven't done any extensive testing besides
> making sure that the TPM responds to pcr reads and some commands like
> reading random numbers.
>
>>
>> Thanks for providing this. Makes it much easier to see what the actual
>> differences between the devices are.
>>
>> Do we have a general policy on how to support devices that are very
>> similar but need special handling in some places? Not duplicating the
>> whole driver just to change a few things definitely seems like an
>> improvement (and has already been done in the past, as with
>> TPM_TIS_ITPM_WORKAROUND). But should all the code just be added to
>> tpm_tis_spi.c? Or is there some way to keep a clearer separation,
>> especially when (in the future) we have multiple devices that all have
>> their own set of deviations from the spec?
>>
>
> If you have any ideas on how to do it please let me know. At this point,
> I'd prefer if the maintainers could provide direction on what they want.
Sure, I'd expect Jarkko will say something once he's back from vacation.
Alexander
next prev parent reply other threads:[~2019-07-19 7:53 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-16 22:45 [PATCH v2 0/6] tpm: Add driver for cr50 Stephen Boyd
2019-07-16 22:45 ` [PATCH v2 1/6] hwrng: core: Freeze khwrng thread during suspend Stephen Boyd
2019-07-17 1:43 ` Herbert Xu
2019-07-17 16:36 ` Stephen Boyd
2019-07-17 11:39 ` Jason Gunthorpe
2019-07-17 16:42 ` Stephen Boyd
2019-07-17 16:50 ` Jason Gunthorpe
2019-07-17 17:03 ` Stephen Boyd
2019-08-02 22:50 ` Stephen Boyd
2019-08-16 15:56 ` Alexander Steffen
2019-08-16 23:55 ` Jarkko Sakkinen
2019-08-02 20:22 ` Jarkko Sakkinen
2019-08-02 23:18 ` Stephen Boyd
2019-07-16 22:45 ` [PATCH v2 2/6] tpm_tis_core: add optional max xfer size check Stephen Boyd
2019-07-16 22:45 ` [PATCH v2 3/6] tpm_tis_spi: add max xfer size Stephen Boyd
2019-07-17 8:07 ` Alexander Steffen
2019-07-17 18:19 ` Stephen Boyd
2019-07-16 22:45 ` [PATCH v2 4/6] dt-bindings: tpm: document properties for cr50 Stephen Boyd
2019-07-16 22:45 ` [PATCH v2 5/6] tpm: add driver for cr50 on SPI Stephen Boyd
2019-07-17 12:00 ` Alexander Steffen
2019-07-17 12:25 ` Jason Gunthorpe
2019-07-17 16:49 ` Stephen Boyd
2019-07-17 16:56 ` Jason Gunthorpe
2019-07-17 17:05 ` Stephen Boyd
2019-07-17 17:12 ` Jason Gunthorpe
2019-07-17 17:22 ` Stephen Boyd
2019-07-17 17:25 ` Jason Gunthorpe
2019-07-17 18:21 ` Stephen Boyd
2019-07-17 18:30 ` Guenter Roeck
2019-07-17 18:36 ` Jason Gunthorpe
2019-07-17 19:57 ` Stephen Boyd
2019-07-17 21:38 ` Stephen Boyd
2019-07-17 22:17 ` Stephen Boyd
2019-07-18 16:47 ` Alexander Steffen
2019-07-18 18:11 ` Stephen Boyd
2019-07-19 7:53 ` Alexander Steffen [this message]
2019-08-01 16:02 ` Stephen Boyd
2019-08-02 15:21 ` Jarkko Sakkinen
2019-08-02 18:03 ` Stephen Boyd
2019-08-02 19:43 ` Jarkko Sakkinen
2019-07-18 16:47 ` Alexander Steffen
2019-07-18 18:07 ` Stephen Boyd
2019-07-19 7:51 ` Alexander Steffen
2019-08-02 20:43 ` Jarkko Sakkinen
2019-08-02 22:32 ` Stephen Boyd
2019-08-02 20:41 ` Jarkko Sakkinen
2019-07-16 22:45 ` [PATCH v2 6/6] tpm: Add driver for cr50 on I2C Stephen Boyd
2019-07-17 15:19 ` Alexander Steffen
2019-08-05 23:52 ` Stephen Boyd
2019-08-02 20:44 ` Jarkko Sakkinen
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=1bb8d417-3199-7aff-ad60-b25464502cb3@infineon.com \
--to=alexander.steffen@infineon.com \
--cc=apronin@chromium.org \
--cc=arnd@arndb.de \
--cc=dlaurie@chromium.org \
--cc=gregkh@linuxfoundation.org \
--cc=groeck@chromium.org \
--cc=jarkko.sakkinen@linux.intel.com \
--cc=jgg@ziepe.ca \
--cc=linux-integrity@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=peterhuewe@gmx.de \
--cc=swboyd@chromium.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).