On Tue, Dec 20, 2011 at 11:00:35AM -0500, Wayne Tams wrote: > Hi Guenter, > > Turns out it was an I2C voltage translator had popped, thankfully all > my I2C devices are ok. Did not realise i2cdetect could behave in such > a peculiar way. > Hi Wayne, please don't top-post. Nothing to do with i2cdetect, but with the i2c bus driver. i2cdetect tries to read, and the bus driver ends up getting a transfer timeout for each read. Depending on the I2C bus chip and the driver, timeouts can be _very_ long, up to 500ms per read or even more. Guenter > Thanks > > Wayne > > On Fri, Dec 16, 2011 at 4:29 PM, Guenter Roeck > <guenter.roeck@xxxxxxxxxxxx> wrote: > > On Fri, 2011-12-16 at 10:33 -0500, Wayne Tams wrote: > >> Hi, > >> > >> i2cdetect is behaving in a fashion that I have not seen before and I > >> just would like to know if anyone has a suggestion on what it is > >> telling me. > >> > >> Normally i2cdetect returns in <1s, if the bus were inactive it would > >> take closer to 20s. However I'm finding that the scanning is taken a > >> round 5s and the addresses returned appear random, except for one. > >> Obviously there must be a fault in my hardware, but I just wanted to > >> make sure that was/wasn't a common explanation for this behaviour > >> before I go debugging up the wrong tree. > > > > I typically see this kind of problem if there is something wrong on the > > i2c bus, for example if a signal is pulled high or low. I have also seen > > it after I managed to physically "destroy" an I2C controller by applying > > a reversed voltage to the i2c signal pins. > > > > If you have a logic analyzer or a scope, you might want to connect it to > > the clock and data lines to see what is happening on the bus. > > > > Guenter > > > > _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
