Subject: Re: i2c-powermac fails

From: Benjamin Herrenschmidt <[email-masked]>
Date: Tue, 13 Oct 2009 20:32:28 +1100

On Tue, 2009-10-13 at 11:23 +0200, Jean Delvare wrote:
> Hi Ben, Paul,
> 
> I had a report by Tim Shepard (Cc'd) that the therm_adt746x driver
> sometimes fails to initialize on his PowerBook G4 running kernel
> 2.6.31. The following error message can be seen in the logs when the
> failure happens:
> 
> therm_adt746x 7-002e: Thermostat failed to read config!
> 
> After enabling low-level i2c debugging, it turns out that the problem
> is caused by low-level errors at the I2C bus level:

Nothing comes to mind immediately, but I'll have another look tomorrow.

Maybe we are configuring the i2c bus too fast ? Another possibility
would be that the device needs some retries ...

Ben.