Re: [PATCH] tpm: fix ATMEL TPM crash caused by too frequent queries

From: Hao Wu <hao.wu@rubrik.com>
To: Jarkko Sakkinen <jarkko@kernel.org>
Cc: Shrihari Kalkar <shrihari.kalkar@rubrik.com>,
	Seungyeop Han <seungyeop.han@rubrik.com>,
	Anish Jhaveri <anish.jhaveri@rubrik.com>,
	peterhuewe@gmx.de, jgg@ziepe.ca, linux-integrity@vger.kernel.org,
	Paul Menzel <pmenzel@molgen.mpg.de>,
	Ken Goldman <kgold@linux.ibm.com>,
	zohar@linux.vnet.ibm.com, why2jjj.linux@gmail.com,
	Hamza Attak <hamza@hpe.com>,
	gregkh@linuxfoundation.org, arnd@arndb.de,
	Nayna <nayna@linux.vnet.ibm.com>,
	James.Bottomley@hansenpartnership.com
Subject: Re: [PATCH] tpm: fix ATMEL TPM crash caused by too frequent queries
Date: Mon, 5 Jul 2021 16:09:10 -0700	[thread overview]
Message-ID: <CE168D94-C8F1-4DDB-B0F5-66E5F1D58097@rubrik.com> (raw)
In-Reply-To: <20210705071531.axxzyvecf52foik2@kernel.org>

> On Jul 5, 2021, at 12:15 AM, Jarkko Sakkinen <jarkko@kernel.org> wrote:
> 
> Is this really the first version? Please, use git-format-patch -vX.
Got it, will re-send the patch with `[PATCH v2]`. 
Thanks for bearing my mistakes, I am not quite familiar with the workflow yet.

> On Sat, Jul 03, 2021 at 05:07:54PM -0700, Hao Wu wrote:
>> This is a fix for the ATMEL TPM crash bug reported in
>> https://patchwork.kernel.org/project/linux-integrity/patch/20200926223150.109645-1-hao.wu@rubrik.com/
>> 
>> According to the discussions in the original thread,
>> we don't want to revert the timeout of wait_for_tpm_stat
>> for non-ATMEL chips, which brings back the performance cost.
>> For investigation and analysis of why wait_for_tpm_stat
>> caused the issue, and how the regression was introduced,
>> please read the original thread above.
> 
> Please, no xrefs. Instead, describe what you are doing.
Ok, will rewrite the commit message
> 
>> Thus the proposed fix here is to only revert the timeout
>> for ATMEL chips by checking the vendor ID.
> 
> What do you mean by reverting?
> 
> The long description needs a full rewrite.
> 
> You can add
> 
> Link: https://patchwork.kernel.org/project/linux-integrity/patch/20200926223150.109645-1-hao.wu@rubrik.com/
> 
> But do not expect anyone to read the thread in order to
> understand what the commit is doing.
> 
>> Fixes: 9f3fc7bcddcb ("tpm: replace msleep() with usleep_range() in TPM 1.2/2.0 generic drivers")
>> Signed-off-by: Hao Wu <hao.wu@rubrik.com>
>> ---
>> Test Plan:
>> - Run fixed kernel with ATMEL TPM chips and see crash
>> has been fixed.
>> - Run fixed kernel with non-ATMEL TPM chips, and confirm
>> the timeout has not been changed.
> 
> The changelog is missing.
Sorry, I don’t get your point here. Could you help clarify it a bit.
I did follow the section 14, but I didn’t see anything specifically needed after `---`
Could you be specific ? Thanks for your time. 

> Please read section 14 of
> 
> https://www.kernel.org/doc/html/v4.17/process/submitting-patches.html
> 
> /Jarkko
Hao