Hi Guenther, I recently became aware of some weird behavior when using the UCD9000 driver for voltage monitoring. We use that device on our zc706 Zynq platform to generate 5 voltage rails. Observing the voltages in Linux showed a correct value for rail 1 but a 2x error in in rails 2-3 and a 4x error in rail 5. Digging through specs, docs and sources I could track this down to this: - The PMBus core assumes one VOUT_MODE register per chip - UCD90120 has VOUT_MODE registers per rail In our setup we have an exponent of -14 for rail 1, -13 for rails 2-4 and -14 for rail 5. The PMBus core only reads and uses the first one and applies it to all rails. I'm not sure whether the UCD devices don't comply to spec or whether this is a bug in the PMBus core, either way, the reported values from the driver are prone to be wrong/scaled by an unknown factor. Is this somehow known behavior for which a workaround might be available? Otherwise, if you know how an acceptable solution might look like, I might find some time and give it a shot. Thanks, Sören _______________________________________________ lm-sensors mailing list lm-sensors@xxxxxxxxxxxxxx http://lists.lm-sensors.org/mailman/listinfo/lm-sensors
