Messages in this thread | | | Date | Thu, 3 Mar 2016 08:29:44 -0800 | From | Eduardo Valentin <> | Subject | Re: [PATCH v2 1/5] thermal: change "hysteresis" as optional property |
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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
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