[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <20141122132309.GC2679@katana>
Date: Sat, 22 Nov 2014 14:23:09 +0100
From: Wolfram Sang <wsa@...-dreams.de>
To: Felipe Balbi <balbi@...com>
Cc: Alexander Kochetkov <al.kochet@...il.com>,
linux-omap@...r.kernel.org, linux-i2c@...r.kernel.org,
linux-kernel@...r.kernel.org, Tony Lindgren <tony@...mide.com>
Subject: Re: [PATCH 2/4] i2c: omap: implement workaround for handling invalid
BB-bit values
On Fri, Nov 21, 2014 at 10:08:08AM -0600, Felipe Balbi wrote:
> On Fri, Nov 21, 2014 at 01:28:43AM +0400, Alexander Kochetkov wrote:
> > In a multimaster environment, after IP software reset, BB-bit value doesn't
> > correspond to the current bus state. It may happen what BB-bit will be 0,
> > while the bus is busy due to another I2C master activity.
> >
> > Any transfer started when BB=0 and bus is busy wouldn't be completed by IP
> > and results in controller timeout. More over, in some cases IP could
> > interrupt another master's transfer and corrupt data on wire.
> >
> > The commit implement method allowing to prevent IP from entering into
> > "controller timeout" state and from "data corruption" state.
> >
> > The one drawback is the need to wait for 10ms before the first transfer.
> >
> > Tested on Beagleboard XM C.
> >
> > Signed-off-by: Alexander Kochetkov <al.kochet@...il.com>
>
> Tested on BBB and AM437x Starter Kit
>
> Tested-by: Felipe Balbi <balbi@...com>
> Reviewed-by: Felipe Balbi <balbi@...com>
Huh, I can't apply this one? Which kernel version is this based on?
Download attachment "signature.asc" of type "application/pgp-signature" (820 bytes)
Powered by blists - more mailing lists