From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Andrzej Siewior Subject: Re: [PATCH 6/7] i2c/pxa2xx: reset the chip if the bus is not free Date: Thu, 25 Nov 2010 14:39:01 +0100 Message-ID: <4CEE66F5.30705@linutronix.de> References: <1290633617-15311-1-git-send-email-bigeasy@linutronix.de> <1290633617-15311-7-git-send-email-bigeasy@linutronix.de> <4CEE05A4.6030201@compulab.co.il> <4CEE5587.90109@linutronix.de> <4CEE602D.5090501@compulab.co.il> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4CEE602D.5090501-UTxiZqZC01RS1MOuV/RT9w@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Igor Grinberg Cc: Haojian Zhuang , eric.y.miao-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, sodaville-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org, Dirk Brandewie , linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org, tglx-hfZtesqFncYOwBW4kG4KsQ@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: linux-i2c@vger.kernel.org Igor Grinberg wrote: > I don't think there is such a rule for this case, as if we "believe" the > Developer Manual, but do the opposite - we can get into trouble... > IMHO, at least we need to report a problem. > > Or may be in some way reset the slave device, > if there is such an option available outside the i2c scope... > (Yeah, I know this is a crazy idea...) Doing the oposite what the manual says is not a good idea. Let's discard the patch for now. >>>> From my experience, in master mode resetting the controller >>> does not help and if the bus is busy for too much time, >>> there always was a h/w problem involved. >> Looks like it. > > 1) Well, you should check if you have a pull-up resistors on that bus. > 2) Or if the slave device chip is broken, then it should be replaced. Thanks for the hint. I try to check the HW and see if there can be done something about it. Sebastian