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 09:51:16 +0200 [thread overview]
Message-ID: <7f570b08-59fb-add9-9502-96d284e0d4da@infineon.com> (raw)
In-Reply-To: <5d30b567.1c69fb81.e6308.74a2@mx.google.com>
On 18.07.2019 20:07, Stephen Boyd wrote:
> Quoting Alexander Steffen (2019-07-18 09:47:14)
>> On 17.07.2019 21:57, Stephen Boyd wrote:
>>>
>>> I think the idea is to let users override the quality if they decide
>>> that they don't want to use the default value specified in the driver.
>>
>> But isn't this something that applies to all TPMs, not only cr50? So
>> shouldn't this parameter be added to one of the global modules (tpm?
>> tpm_tis_core?) instead? Or do all low-level drivers (tpm_tis,
>> tpm_tis_spi, ...) need this parameter to provide a consistent interface
>> for the user?
>
> Looking at commit 7a64c5597aa4 ("tpm: Allow tpm_tis drivers to set hwrng
> quality.") I think all low-level drivers need to set the hwrng quality
> somehow. I'm not sure how tpm_tis_spi will do that in general, but at
> least for cr50 we have derived this quality number.
>
> I can move this module parameter to tpm_tis_core.c, but then it will be
> a global hwrng quality override for whatever tpm is registered through
> tpm_tis_core instead of per-tpm driver. This is sort of a problem right
> now too if we have two tpm_tis_spi devices. I can drop this parameter if
> you want.
Since it does not seem like a critical feature, maybe just drop it for
now. Then we can figure out a way to do it properly and add it later.
Alexander
next prev parent reply other threads:[~2019-07-19 7:51 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
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 [this message]
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
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