On Mon, Feb 25, 2013 at 11:06:40AM +0800, Zhang Rui wrote: > when the temperature goes up to 50C, will the fan be turned on or not?
Right, let's first clarify this: so we want the fan to go on when it reaches and/or exceeds the 'fanon' temperature and to go off after it goes under the 'fanoff' temperature. It is supposed to remain on in the [fanoff,fanon] interval. Now, my observation from yesterday was that, if we don't do the flattening of the abovementioned interval in acerhdf_set_cur_state() but we simply turn on the fan if we receive state=1 and turn it off when state=0, the fan gets turned on only for short bursts when the governor decides it is time to throttle, i.e. the temperature in the zone is rising and turns it off when the temperature starts to fall again. And it would turn on the fan at lower temperatures than fanon. But this is annoying. The main reason why this acerhdf thing was added in the first place was to do a better fan control on those machines because the fans are noisy. Basically, enable the fan only when really needed - and leave it off when not because it is really annoying. When enabled, however, leave it on longer until a safe, 'fanoff' temperature is reached. Am I making more sense now? Peter? Thanks. -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. -- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/