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Message-ID: <6131ffd5cd7455426ea5f68633d5a8c8dd8457bb.camel@linux.intel.com>
Subject: Re: [PATCH v2 01/10] tpm/tpm_i2c_infineon: switch to
 i2c_lock_bus(..., I2C_LOCK_SEGMENT)
From:   Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
To:     Alexander Steffen <Alexander.Steffen@infineon.com>,
        Peter Rosin <peda@axentia.se>
Cc:     linux-kernel@vger.kernel.org, Peter Huewe <peterhuewe@gmx.de>,
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Date:   Tue, 26 Jun 2018 15:07:59 +0300
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         <7703d6a2-b22c-104c-7390-b5143a504725@infineon.com>
         <6169da633eab7e68d645e6b933b605dcc9ae09f1.camel@linux.intel.com>
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On Tue, 2018-06-26 at 15:05 +0300, Jarkko Sakkinen wrote:
> On Tue, 2018-06-26 at 12:07 +0200, Alexander Steffen wrote:
> > On 25.06.2018 12:24, Jarkko Sakkinen wrote:
> > > On Wed, Jun 20, 2018 at 07:17:54AM +0200, Peter Rosin wrote:
> > > > Locking the root adapter for __i2c_transfer will deadlock if the
> > > > device sits behind a mux-locked I2C mux. Switch to the finer-grained
> > > > i2c_lock_bus with the I2C_LOCK_SEGMENT flag. If the device does not
> > > > sit behind a mux-locked mux, the two locking variants are equivalent.
> > > > 
> > > > Signed-off-by: Peter Rosin <peda@axentia.se>
> > > 
> > > Studied enough so that I can give
> > > 
> > > Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
> > > 
> > > Do not have hardware to test this, however.
> > 
> > I don't have a mux-locked I2C mux either, but at least I can confirm 
> > that this change did not break my existing test setup (SLB9635/SLB9645 
> > on Raspberry Pi 2B).
> > 
> > Tested-by: Alexander Steffen <Alexander.Steffen@infineon.com>
> > 
> > Alexander
> 
> Given the scope of the change and since analogous change works for
> every other subsystem, this should be enough! Thank you.

It is now applied to my tree (master). I will move it to the
next branch once James has updated security/next-general.

/Jarkko