From: Eugene Surovegin <ebs@ebshome.net>
To: Wolfgang Denk <wd@denx.de>
Cc: Miku Jha <jha_miku@yahoo.com>, linuxppc-embedded@lists.linuxppc.org
Subject: Re: ppc440 and i2c
Date: Tue, 18 Nov 2003 00:42:47 -0800 [thread overview]
Message-ID: <20031118084247.GB28129@gate.ebshome.net> (raw)
In-Reply-To: <20031118082248.38F8DC5F59@atlas.denx.de>
On Tue, Nov 18, 2003 at 09:22:43AM +0100, Wolfgang Denk wrote:
>
> > If bootstrap IIC is accidentaly activated you may get problems if you
> > have non-compliant/not-properly-reset device on IIC0 bus.
>
> The problem is an I2C Edge Condition which means that I2C devices may
> be left in a write state if a read was occuring and the CPU was
> reset. This may for example result in EEPROM data corruption.
>
Well, I just read doc from U-Boot, and as far as I understand "I2C
Edge Condition" _cannot_ cause 440 to hang as it was described in the
parent post. Sure, it may cause some unlikely corruption but that's
it (provided we haven't corrupted bootstrap EEPROM itself :).
That's why I suspected some bootstrap IIC interaction with
non-properly-reset i2c device left in some intermediate state (as
show in U-Boot doc for example).
Eugene.
** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/
next prev parent reply other threads:[~2003-11-18 8:42 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-11-18 7:18 ppc440 and i2c Miku Jha
2003-11-18 8:08 ` Eugene Surovegin
2003-11-18 8:22 ` Wolfgang Denk
2003-11-18 8:42 ` Eugene Surovegin [this message]
2003-11-18 8:55 ` Robert Berger
2003-11-18 8:09 ` Wolfgang Denk
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20031118084247.GB28129@gate.ebshome.net \
--to=ebs@ebshome.net \
--cc=jha_miku@yahoo.com \
--cc=linuxppc-embedded@lists.linuxppc.org \
--cc=wd@denx.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.