From: Mimi Zohar <zohar@linux.ibm.com>
To: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>,
Calvin Owens <calvinowens@fb.com>
Cc: Peter Huewe <peterhuewe@gmx.de>, Jason Gunthorpe <jgg@ziepe.ca>,
Arnd Bergmann <arnd@arndb.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org,
kernel-team@fb.com
Subject: Re: [PATCH] tpm: Make timeout logic simpler and more robust
Date: Tue, 12 Mar 2019 12:56:37 -0400 [thread overview]
Message-ID: <1552409797.24794.65.camel@linux.ibm.com> (raw)
In-Reply-To: <20190312123632.GB9243@linux.intel.com>
On Tue, 2019-03-12 at 14:36 +0200, Jarkko Sakkinen wrote:
> On Mon, Mar 11, 2019 at 04:54:04PM -0700, Calvin Owens wrote:
> > We're having lots of problems with TPM commands timing out, and we're
> > seeing these problems across lots of different hardware (both v1/v2).
> >
> > I instrumented the driver to collect latency data, but I wasn't able to
> > find any specific timeout to fix: it seems like many of them are too
> > aggressive. So I tried replacing all the timeout logic with a single
> > universal long timeout, and found that makes our TPMs 100% reliable.
> >
> > Given that this timeout logic is very complex, problematic, and appears
> > to serve no real purpose, I propose simply deleting all of it.
> >
> > Signed-off-by: Calvin Owens <calvinowens@fb.com>
>
> Have been thinking about this and I do agree. It has been like that
> before my times with this subsystem so when I did the original TPM2
> patches I carried this logic albeit even at that point I did not get it.
> Now that I've been maintaining for over three years I'm confident that
> this the Right Thing to do.
Please really consider this impact on IMA, before making this change.
Mimi
next prev parent reply other threads:[~2019-03-12 16:56 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-11 23:54 [PATCH] tpm: Make timeout logic simpler and more robust Calvin Owens
2019-03-12 0:27 ` James Bottomley
2019-03-12 12:50 ` Jarkko Sakkinen
2019-03-12 14:42 ` James Bottomley
2019-03-12 15:39 ` Jarkko Sakkinen
2019-03-12 19:41 ` Calvin Owens
2019-03-12 16:59 ` Mimi Zohar
2019-03-12 17:14 ` James Bottomley
2019-03-12 18:32 ` Mimi Zohar
2019-03-12 19:37 ` Calvin Owens
2019-03-12 12:36 ` Jarkko Sakkinen
2019-03-12 16:56 ` Mimi Zohar [this message]
2019-03-12 14:55 ` Jarkko Sakkinen
2019-03-12 17:04 ` Mimi Zohar
2019-03-12 20:08 ` Calvin Owens
2019-03-12 20:56 ` Mimi Zohar
2019-03-13 13:22 ` Jarkko Sakkinen
2019-03-13 13:23 ` Jarkko Sakkinen
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