Re: [PATCH v3] tpm: Enable hwrng only for Pluton on AMD CPUs

[Mario Limonciello <mario.limonciello@amd.com>]

On 8/27/2023 13:12, Jarkko Sakkinen wrote:
> On Wed Aug 23, 2023 at 9:58 PM EEST, Mario Limonciello wrote:
>> On 8/23/2023 12:40, Jarkko Sakkinen wrote:
>>> On Wed Aug 23, 2023 at 11:23 AM EEST, Paul Menzel wrote:
>>>> Dear Jarkko,
>>>>
>>>>
>>>> Thank you for your patch.
>>>>
>>>>
>>>> Am 23.08.23 um 01:15 schrieb Jarkko Sakkinen:
>>>>> The vendor check introduced by commit 554b841d4703 ("tpm: Disable RNG for
>>>>> all AMD fTPMs") doesn't work properly on a number of Intel fTPMs.  On the
>>>>> reported systems the TPM doesn't reply at bootup and returns back the
>>>>> command code. This makes the TPM fail probe.
>>>>>
>>>>> Since only Microsoft Pluton is the only known combination of AMD CPU and
>>>>> fTPM from other vendor, disable hwrng otherwise. In order to make sysadmin
>>>>> aware of this, print also info message to the klog.
>>>>>
>>>>> Cc: stable@vger.kernel.org
>>>>> Fixes: 554b841d4703 ("tpm: Disable RNG for all AMD fTPMs")
>>>>> Reported-by: Todd Brandt <todd.e.brandt@intel.com>
>>>>> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217804
>>>>> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
>>>>
>>>> Mario’s patch also had the three reporters below listed:
>>>>
>>>> Reported-by: Patrick Steinhardt <ps@pks.im>
>>>> Reported-by: Ronan Pigott <ronan@rjp.ie>
>>>> Reported-by: Raymond Jay Golo <rjgolo@gmail.com>
>>>
>>> The problem here is that checkpatch throws three warnings:
>>>
>>> WARNING: Reported-by: should be immediately followed by Closes: with a URL to the report
>>> #19:
>>> Reported-by: Patrick Steinhardt <ps@pks.im>
>>> Reported-by: Ronan Pigott <ronan@rjp.ie>
>>>
>>> WARNING: Reported-by: should be immediately followed by Closes: with a URL to the report
>>> #20:
>>> Reported-by: Ronan Pigott <ronan@rjp.ie>
>>> Reported-by: Raymond Jay Golo <rjgolo@gmail.com>
>>>
>>> WARNING: Reported-by: should be immediately followed by Closes: with a URL to the report
>>> #21:
>>> Reported-by: Raymond Jay Golo <rjgolo@gmail.com>
>>> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
>>>
>>
>> FWIW I observed the same checkpatch warning when I submitted my version
>> of the patch.  I figured it's better to ignore the warning and attribute
>> everyone who reported the issue affected them.
> 
> OK so:
> 
> 1. checkpatch.pl is part of the kernel process.
> 2. Bugzilla is not part of the kernel process.
> 
> Why emphasis on 1?
> 
> BR, Jarkko

The reason I submitted it this way is because of this quote from the 
documentation [1].

"Check your patches with the patch style checker prior to submission 
(scripts/checkpatch.pl). Note, though, that the style checker should be 
viewed as a guide, not as a replacement for human judgment. If your code 
looks better with a violation then its probably best left alone."

I wanted the patch to capture and attribute all those that reported it 
not just the "first one".  Like I said previously, it's better to have a 
collection of people to ping to notify if something needs to be reverted.

[1] 
https://www.kernel.org/doc/html/latest/process/submitting-patches.html#style-check-your-changes