From mboxrd@z Thu Jan  1 00:00:00 1970
From: Steve Sakoman <steve@sakoman.com>
Date: Wed, 17 Nov 2010 14:48:59 -0800
Subject: [U-Boot] fw_setenv broken?
In-Reply-To: <20101117160802.5bacf545@udp111988uds.am.freescale.net>
References: <1290011424.2927.1123.camel@quadra> <4CE4092B.7090209@denx.de>
	<20101117173933.665FE14EA7E@gemini.denx.de>
	<AANLkTikaLbZG5ED=p-_0MWoLOjH=kfna-P8SYAC=Nisx@mail.gmail.com>
	<20101117204722.E34FC14EA7E@gemini.denx.de>
	<AANLkTimrfQ5+AWfdFy_fueTMH=x=xrkaZGNtK8fiSD48@mail.gmail.com>
	<20101117214049.52CA614EA7E@gemini.denx.de>
	<20101117160802.5bacf545@udp111988uds.am.freescale.net>
Message-ID: <1290034139.2927.1192.camel@quadra>
List-Id: <u-boot.lists.denx.de>
MIME-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
To: u-boot@lists.denx.de

On Wed, 2010-11-17 at 16:08 -0600, Scott Wood wrote:
> On Wed, 17 Nov 2010 22:40:49 +0100
> Wolfgang Denk <wd@denx.de> wrote:
> 
> > Dear Steve Sakoman,
> > 
> > In message <AANLkTimrfQ5+AWfdFy_fueTMH=x=xrkaZGNtK8fiSD48@mail.gmail.com> you wrote:
> > >
> > > readenv: offset = 240000
> > > readenv: nand_read failure = -117
> > > *** Warning - readenv() failed, using default environment
> > > 
> > > I then immediately tried to use the nand read command to read the same
> > > block, and it was successful!
> > 
> > Hm... any chance that - for example - your timers are not working
> > correctly before relocation (maybe because they try to write to the
> > not yet available data segment) ? This could cause timeouts or delays
> > to be too short, so the NAND driver is misbehaving?
> 
> The NAND driver only works after relocation.
> 
> It looks like the problem is that -EUCLEAN is a non-fatal error
> (indicates a correctable ECC error).  The code invoked by the "nand
> read" command succeeds if nand_read() returns either 0 or -EUCLEAN, but
> readenv() is missing this check.

OK, we seem to be peeling back the layers of the onion now.

I patched readenv to use the same nand_read_skip_bad function used in
the command line "nand read" tool.  I no longer get the -EUCLEAN errors
when reading the environment after using fw_setenv to write from linux.
Now I get:

*** Warning - bad CRC, using default environment

Checking the data with the "nand read" command line shows that the
changes I made in linux are indeed there, so I suspect that there is
also some mismatch in the CRC computation between the fw tools and the
u-boot code (i.e. I'm pretty sure this error does *not* refer to the
nand CRC)

Steve