linux-kernel - Re: [BISECTED] tpm CLKRUN breaks PS/2 keyboard and touchpad on Braswell system

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Message-ID: <20171219130200.7zez4bnh3f3yvuzv@linux.intel.com>
Date:   Tue, 19 Dec 2017 15:02:00 +0200
From:   Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
To:     Jason Gunthorpe <jgg@...pe.ca>
Cc:     Javier Martinez Canillas <javierm@...hat.com>,
        James Ettle <james@...le.org.uk>,
        linux-integrity@...r.kernel.org, azhar.shaikh@...el.com,
        linux-kernel@...r.kernel.org, james.l.morris@...cle.com
Subject: Re: [BISECTED] tpm CLKRUN breaks PS/2 keyboard and touchpad on
 Braswell system

On Mon, Dec 18, 2017 at 10:55:02AM -0700, Jason Gunthorpe wrote:
> On Mon, Dec 18, 2017 at 01:29:01PM +0100, Javier Martinez Canillas wrote:
> > On 12/18/2017 01:22 PM, Javier Martinez Canillas wrote:
> > 
> > [snip]
> > 
> > > 
> > > James,
> > > 
> > > Can you please test the following (untested) patch on top of the other two
> > > mentioned patches to see if it makes a difference for you?
> > > 
> > 
> > I should had tried to at least compile the patch :)
> 
> I think this is backwards..
> 
> If CLKRUN_EN is on (eg power management is NOT enabled on LPC) then
> TPM shouldn't do anything at all.
> 
> If CLKRUN_EN is off, then it should try to turn it on/off to save
> power.
> 
> Perhaps the best work around is to just delete the turning off of
> CLKRUN_EN ? Uses more power but keeps the clock running which should
> keep both TPM and superio happy.
> 
> Jason

On some BSW systems keeping CLKRUN_EN on during TPM command caused
issues. That was the original reason for the fixes.

/Jarkko