On Tue, Dec 20, 2011 at 4:18 PM, Guenter Roeck <guenter.roeck@xxxxxxxxxxxx> wrote: > 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. Sorry was not not thinking...end of the day > > 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. I see, that makes sense. Once again thanks Wayne > > 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
