i2c-powermac fails

2009-10-13 Thread Jean Delvare
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 en

Re: i2c-powermac fails

2009-10-13 Thread Benjamin Herrenschmidt
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:

Re: i2c-powermac fails

2009-10-13 Thread Jean Delvare
On Tue, 13 Oct 2009 20:32:28 +1100, Benjamin Herrenschmidt wrote: > 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. T

Re: i2c-powermac fails

2009-10-14 Thread Jean Delvare
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. May

Re: i2c-powermac fails

2009-10-14 Thread Benjamin Herrenschmidt
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

Re: i2c-powermac fails

2009-10-15 Thread Jean Delvare
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

Re: i2c-powermac fails

2009-10-15 Thread Benjamin Herrenschmidt
On Thu, 2009-10-15 at 12:49 +0200, Jean Delvare wrote: > 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? No but maybe we are a bit on the "limit" of the device and some registers

Re: i2c-powermac fails

2009-10-15 Thread Jean Delvare
On Thu, 15 Oct 2009 22:19:19 +1100, Benjamin Herrenschmidt wrote: > On Thu, 2009-10-15 at 12:49 +0200, Jean Delvare wrote: > > 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? >

Re: i2c-powermac fails

2009-10-16 Thread Jean Delvare
On Thu, 15 Oct 2009 16:05:13 +0200, Jean Delvare wrote: > On Thu, 15 Oct 2009 22:19:19 +1100, Benjamin Herrenschmidt wrote: > > On Thu, 2009-10-15 at 12:49 +0200, Jean Delvare wrote: > > > Oh. Well, if that was the case, we would see errors all the time, not > > > just during initialization, right?

Re: i2c-powermac fails

2009-10-16 Thread Benjamin Herrenschmidt
On Fri, 2009-10-16 at 09:44 +0200, Jean Delvare wrote: > On Thu, 15 Oct 2009 16:05:13 +0200, Jean Delvare wrote: > > On Thu, 15 Oct 2009 22:19:19 +1100, Benjamin Herrenschmidt wrote: > > > On Thu, 2009-10-15 at 12:49 +0200, Jean Delvare wrote: > > > > Oh. Well, if that was the case, we would see er