linux-kernel - Re: [PATCH 4/5] i2c: octeon,thunderx: Check bus state before starting a transaction

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Date:   Thu, 22 Sep 2016 18:08:32 +0200
From:   Jan Glauber <jan.glauber@...iumnetworks.com>
To:     Wolfram Sang <wsa@...-dreams.de>
CC:     <linux-kernel@...r.kernel.org>, <linux-i2c@...r.kernel.org>,
        "Bazhenov, Dmitry" <dmitry.bazhenov@...iga.com>
Subject: Re: [PATCH 4/5] i2c: octeon,thunderx: Check bus state before
 starting a transaction

On Wed, Sep 21, 2016 at 10:55:41PM +0200, Wolfram Sang wrote:
> On Wed, Sep 21, 2016 at 08:51:05AM +0200, Jan Glauber wrote:
> > Add an additional status check before starting a transaction and,
> > if required, trigger the recovery if the check fails.
> > 
> > Signed-off-by: Jan Glauber <jglauber@...ium.com>
> 
> Won't this break multi-master setups?
> 

I'm afraid yes. I don't have a multi-master setup, but agree that we
should not break it.

How about re-checking if the bus is idle until a timeout
(i2c->adap.timeout ?) happens and only then recover?

Additionaly we can check for arbitration loss as Dmitry did in his
original patch.

--Jan