linux-kernel - Re: TPM chip prevents machine from suspending

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Date:	Tue, 29 Mar 2011 08:30:35 -0400
From:	Jeff Layton <jlayton@...chiereds.net>
To:	Stefan Berger <stefanb@...ux.vnet.ibm.com>
Cc:	linux-kernel@...r.kernel.org, tpmdd-devel@...ts.sourceforge.net,
	"debora@...ux.vnet.ibm.com" <debora@...ux.vnet.ibm.com>,
	Rajiv Andrade <srajiv@...ux.vnet.ibm.com>
Subject: Re: TPM chip prevents machine from suspending

On Tue, 29 Mar 2011 08:25:01 -0400
Stefan Berger <stefanb@...ux.vnet.ibm.com> wrote:

> >> Another possibility would be for you to check for BIOS updates from the
> >> laptop manufacturer...
> >>
> > This is actually a desktop machine and the BIOS for the motherboard is
> > at the latest version, though it is quite old -- 2007/09/01. For the
> > record this is a:
> >
> >       Foxconn 6150BK8MC
> >
> > I'm actually not using the TPM in this thing at all. I'd be just as
> > happy if there were some way to disable it. Unfortunately, the option
> > in the BIOS to do this doesn't seem to actually work. When I set "TPM
> > Control" in the BIOS to "Disable" it always ends up reset back to "No
> > Change". I'd report both problems to the mfr, but this thing is long
> > out of warranty and I'm pretty sure they won't care.
> >
> > Is there some way short of recompiling with CONFIG_TCG_* turned off
> > to disable the TPM driver at boot time?
> >
> As far as I know, 'no'. I'd defer it to the maintainers as to how they 
> would want to solve your particular problem... either by using above 
> work-around, which would be more transparent, or actively having to turn 
> the driver off with a command line parameter.
> 

I'm fine with leaving it enabled as long as it doesn't get in the way
of suspend working. The scheme you mention above -- test the chip and
conditionally do a TPM_Startup() seems reasonable to me. Let me know if
you need me to test a patch...

Thanks,
-- 
Jeff Layton <jlayton@...chiereds.net>
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