From: Jean Delvare <khali@linux-fr.org>
To: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>,
Tim Shepard <shep@alum.mit.edu>,
linuxppc-dev@ozlabs.org
Subject: Re: i2c-powermac fails
Date: Thu, 15 Oct 2009 12:49:23 +0200 [thread overview]
Message-ID: <20091015124923.23863a94@hyperion.delvare> (raw)
In-Reply-To: <1255555575.2347.56.camel@pasglop>
On Thu, 15 Oct 2009 08:26:15 +1100, Benjamin Herrenschmidt wrote:
> On Wed, 2009-10-14 at 23:02 +0200, Jean Delvare wrote:
> > Hi all,
> >
> > On Tue, 13 Oct 2009 11:49:48 +0200, Jean Delvare wrote:
> > > I2C bus being setup too fast sounds more likely. It might be worth
> > > adding an arbitrary delay after initialization, just to see if it
> > > helps. Not sure where though, as I'm not familiar with the Powermac
> > > initialization steps. Maybe right before i2c_add_adapter() in
> > > i2c_powermac_probe?
> >
> > Tim, can you please give a try to this patch? Obviously your machine
> > will take 5 additional seconds to boot, and this isn't meant as a real
> > fix, but if it helps, this will be an interesting hint for further
> > debugging attempts.
>
> Oh, I was actually thinking about the frequency of the I2C clock :-)
Oh. Well, if that was the case, we would see errors all the time, not
just during initialization, right? Or does the I2C clock frequency
change over time somehow?
--
Jean Delvare
next prev parent reply other threads:[~2009-10-15 10:49 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-13 9:23 i2c-powermac fails Jean Delvare
2009-10-13 9:32 ` Benjamin Herrenschmidt
2009-10-13 9:49 ` Jean Delvare
2009-10-14 21:02 ` Jean Delvare
2009-10-14 21:26 ` Benjamin Herrenschmidt
2009-10-15 10:49 ` Jean Delvare [this message]
2009-10-15 11:19 ` Benjamin Herrenschmidt
2009-10-15 14:05 ` Jean Delvare
2009-10-16 7:44 ` Jean Delvare
2009-10-16 8:42 ` Benjamin Herrenschmidt
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