On Sun, Feb 13, 2011 at 09:52:25AM -0500, Devin Heitmueller wrote: > On Sun, Feb 13, 2011 at 9:47 AM, Mark Zimmerman <markzimm@xxxxxxxx> wrote: > > Clearly my previous bisection went astray; I think I have a more > > sensible result this time. > > > > qpc$ git bisect good > > 44835f197bf1e3f57464f23dfb239fef06cf89be is the first bad commit > > commit 44835f197bf1e3f57464f23dfb239fef06cf89be > > Author: Jean Delvare <khali@xxxxxxxxxxxx> > > Date: ? Sun Jul 18 16:52:05 2010 -0300 > > > > ? ?V4L/DVB: cx23885: Check for slave nack on all transactions > > > > ? ?Don't just check for nacks on zero-length transactions. Check on > > ? ?other transactions too. > > This could be a combination of the xc5000 doing clock stretching and > the cx23885 i2c master not properly implementing clock stretch. In > the past I've seen i2c masters broken in their handling of clock > stretching where they treat it as a NAK. > > The xc5000 being one of the few devices that actually does i2c clock > stretching often exposes cases where it is improperly implemented in > the i2c master driver (I've had to fix this with several bridges). > Thanks for your insight. I am looking at cx23885-i2c.c and there is no clock stretching logic in i2c_slave_did_ack(). Would this be the right place for it to be? Can you point me to an example of another driver that does it correctly? I really don't know what I am doing... -- Mark -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
