From mboxrd@z Thu Jan  1 00:00:00 1970
From: u.kleine-koenig@pengutronix.de (Uwe =?iso-8859-1?Q?Kleine-K=F6nig?=)
Date: Fri, 10 Aug 2012 22:14:56 +0200
Subject: Lockups reading from i.MX51 SSI registers
In-Reply-To: <20120810195638.GF1451@pengutronix.de>
References: <20120810195005.GP24328@opensource.wolfsonmicro.com>
 <20120810195638.GF1451@pengutronix.de>
Message-ID: <20120810201456.GL25520@pengutronix.de>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Hi,

On Fri, Aug 10, 2012 at 09:56:38PM +0200, Sascha Hauer wrote:
> On Fri, Aug 10, 2012 at 08:50:08PM +0100, Mark Brown wrote:
> > I'm trying to use -next to test AC'97 register I/O on an i.MX51 board
> > but I'm seeing the CPU hang during probe at:
> > 
> > 	lreg = (reg & 0x7f) <<  12 ;
> > 	writel(lreg, base + SSI_SACADD);
> > 
> > in imx_ssi_ac97_read().  I'm somewhat suspicious this might be because
> > the IP block isn't clocked properly, I do notice the recent conversion
> > to the clock API which looks rather involved but it's possible something
> > else broke.  Does anyone have any bright ideas what might be going on
> > here?  The board doesn't have the reste functions defined so this is the
> > first interaction with the hardware block AFAICT.
> 
> No idea currently, just adding Uwe to Cc because I think he has seen
> something similar on an i.MX35 board recently.
I havn't debugged that yet, but one issue I think needs to be solved is
that since the clk conversion there are two ssi clocks. And from a quick
look the ssi driver only handles one of them.

Uwe

-- 
Pengutronix e.K.                           | Uwe Kleine-K?nig            |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |