From: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To: Omar Sandoval <osandov@osandov.com>
Cc: Peter Huewe <peterhuewe@gmx.de>, Jason Gunthorpe <jgg@ziepe.ca>,
linux-integrity@vger.kernel.org
Subject: Re: [PATCH] tpm_tis: work around status register bug in STMicroelectronics TPM
Date: Sat, 18 Apr 2020 02:54:06 +0300 [thread overview]
Message-ID: <20200417235406.GA85230@linux.intel.com> (raw)
In-Reply-To: <20200416185433.GA701157@vader>
On Thu, Apr 16, 2020 at 11:54:33AM -0700, Omar Sandoval wrote:
> On Thu, Apr 16, 2020 at 08:08:10PM +0300, Jarkko Sakkinen wrote:
> > On Wed, Apr 15, 2020 at 03:45:22PM -0700, Omar Sandoval wrote:
> > > From: Omar Sandoval <osandov@fb.com>
> > >
> > > We've encountered a particular model of STMicroelectronics TPM that
> > > transiently returns a bad value in the status register. This causes the
> > > kernel to believe that the TPM is ready to receive a command when it
> > > actually isn't, which in turn causes the send to time out in
> > > get_burstcount(). In testing, reading the status register one extra time
> > > convinces the TPM to return a valid value.
> > >
> > > Signed-off-by: Omar Sandoval <osandov@fb.com>
> >
> > So what is the bad value?
>
> 0xff. Sorry, I thought it would be clear from the code and comment in
> the patch itself. Would you prefer for me to repeat it in the commit
> message?
It is part of the problem description where as "bad value" does
not have any particular meaning.
/Jarkko
prev parent reply other threads:[~2020-04-17 23:54 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-15 22:45 [PATCH] tpm_tis: work around status register bug in STMicroelectronics TPM Omar Sandoval
2020-04-15 23:51 ` James Bottomley
2020-04-16 0:16 ` Omar Sandoval
2020-04-16 0:24 ` Omar Sandoval
2020-04-16 18:02 ` James Bottomley
2020-04-17 23:55 ` Jarkko Sakkinen
2020-04-18 0:12 ` James Bottomley
2020-04-20 20:46 ` Jarkko Sakkinen
2020-04-20 22:28 ` James Bottomley
2020-04-21 14:36 ` Mimi Zohar
2020-04-21 20:25 ` Jarkko Sakkinen
2020-04-21 20:31 ` Mimi Zohar
2020-04-21 20:23 ` Jarkko Sakkinen
2020-04-21 22:08 ` James Bottomley
2020-04-16 17:09 ` Jarkko Sakkinen
2020-04-16 17:56 ` James Bottomley
2020-08-27 15:24 ` Jason Andryuk
2020-08-28 23:18 ` Jarkko Sakkinen
2020-08-29 0:12 ` Jason Andryuk
2020-08-31 13:55 ` Jarkko Sakkinen
2020-09-04 12:03 ` Jarkko Sakkinen
2020-04-16 17:08 ` Jarkko Sakkinen
2020-04-16 18:54 ` Omar Sandoval
2020-04-17 23:54 ` Jarkko Sakkinen [this message]
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