Messages in this thread | | | Date | Thu, 17 Jul 2014 11:58:55 +0200 | From | Borislav Petkov <> | Subject | Re: [PATCH v3 3/6] thermal: Added Bang-bang thermal governor |
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On Sat, May 03, 2014 at 07:59:23PM +0200, Peter Feuerer wrote: > The bang-bang thermal governor uses a hysteresis to switch abruptly on > or off a cooling device. It is intended to control fans, which can > not be throttled but just switched on or off. > Bang-bang cannot be set as default governor as it is intended for > special devices only. For those special devices the driver needs to > explicitely request it. > > Cc: Andrew Morton <akpm@linux-foundation.org> > Cc: Zhang Rui <rui.zhang@intel.com> > Cc: Andreas Mohr <andi@lisas.de> > Cc: Borislav Petkov <bp@suse.de> > Cc: Javi Merino <javi.merino@arm.com> > Signed-off-by: Peter Feuerer <peter@piie.net>
...
> +static void thermal_zone_trip_update(struct thermal_zone_device *tz, int trip) > +{ > + long trip_temp; > + unsigned long trip_hyst; > + struct thermal_instance *instance; > + > + tz->ops->get_trip_temp(tz, trip, &trip_temp); > + tz->ops->get_trip_hyst(tz, trip, &trip_hyst); > + > + dev_dbg(&tz->device, "Trip%d[temp=%ld]:temp=%d:hyst=%ld\n", > + trip, trip_temp, tz->temperature, > + trip_hyst); > + > + mutex_lock(&tz->lock); > + > + list_for_each_entry(instance, &tz->thermal_instances, tz_node) { > + if (instance->trip != trip) > + continue; > + > + /* in case fan is in initial state, switch the fan off */ > + if (instance->target == THERMAL_NO_TARGET) > + instance->target = 0; > + > + /* in case fan is neither on nor off set the fan to active */ > + if (instance->target != 0 && instance->target != 1) {
->target is unsigned long so
if (instance->target > 1)
(and btw, a whole unsigned long for a cooling state... 2^64-1 cooling states, nice).
> + pr_warn("Thermal instance %s controlled by bang-bang has unexpected state: %ld\n", > + instance->name, instance->target); > + instance->target = 1; > + }
Can that even happen?
-- Regards/Gruss, Boris.
Sent from a fat crate under my desk. Formatting is fine. --
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