Hi Leo, On Fri, Feb 26, 2016 at 11:43:43AM +0800, Leo Yan wrote: > The property "hysteresis" is mandatory for trip points, so if without > it the thermal zone cannot register successfully. But "hysteresis" is > ignored in the thermal subsystem and only inquired by several thermal > sensor drivers. I am not sure this a good direction to go. Remember that Linux implementation not necessarily has to be the implication of the DT binding. Hysteresis is a property that plays a significant role on thermal control systems, which in many cases avoid overshooting cooling actions. Having the DT writer to explicitly set it to 0 means that zone does not suffer of overshooting and does not need hysteresis. If the Linux thermal subsystem has a problem with handling hysteresis, I would rather fix Linux code than relaxing the DT binding. Or if you still believe hysteresis is really optional, I would prefer to see a better justification than "Linux ignores it". BR, Eduardo -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
