From mboxrd@z Thu Jan  1 00:00:00 1970
From: Steve Sakoman <steve@sakoman.com>
Date: Fri, 15 Oct 2010 12:48:57 -0700
Subject: [U-Boot] [PATCH RFC] ARMV7: OMAP: I2C driver: Reduce
 excessively long udelay calls
In-Reply-To: <20101015192718.6340C1365CF@gemini.denx.de>
References: <1287158873.7756.66.camel@quadra>
	<20101015192718.6340C1365CF@gemini.denx.de>
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On Fri, 2010-10-15 at 21:27 +0200, Wolfgang Denk wrote:
> Dear Steve Sakoman,
> 
> In message <1287158873.7756.66.camel@quadra> you wrote:
> > I've been preparing a patch series for Beagle and Overo that detects expansion
> > board configuration information by reading a 128 byte I2C EEPROM on each
> > expansion board.
> > 
> > Using the OMAP I2C driver in its current form takes about 5-6 seconds to read
> > this small number of bytes!
> > 
> > Examining the code I see that there are a large number of fairly long udelay calls
> > throughout the driver (10 - 50 milliseconds). I looked through the linux driver
> > and did not see equivalent delays in that code.  In fact the longest delay in the
> > linux code was one millisecond.
> 
> Eventually the long delays are needed to make the code work stable
> even under rare conditions, which don't happen to often.  But this may
> be caused by the way the code is written, too...

<snip>

> My feeling is that this driver needs a more thorough rework.

Unfortunately I am inclined to agree with you!

I'll start work on that.

Steve