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? > > No but maybe we are a bit on the "limit" of the device and some > registers take long to respond than others ?
Unlikely. The ADT7460 can run at I2C clock rates up to 400 kHz while the Keywest I2C runs at 25, 50 or 100 kHz if I read the code properly. I don't know what exact speed is used on Tim's system, apparently it is read from the hardware in the device tree directly? We could have low_i2c.c log the I2C clock frequency and/or try to force the lowest speed (25 kHz) and see if it helps, but I very much doubt it. And I'd rather wait for Tim to report the result with my last patch first. -- Jean Delvare _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev