PM: domains: Fix initialization of genpd's next_wakeup

In the genpd governor we walk the list of child-domains to take into
account their next_wakeup. If the child-domain itself, doesn't have a
governor assigned to it, we can end up using the next_wakeup value before
it has been properly initialized. To prevent a possible incorrect behaviour
in the governor, let's initialize next_wakeup to KTIME_MAX.

Fixes: c79aa08 ("PM: domains: use device's next wakeup to determine domain idle state")
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Author: Ulf Hansson

drivers/base/power/domain.c

@@ -2007,6 +2007,7 @@ int pm_genpd_init(struct generic_pm_domain *genpd,
 	genpd->device_count = 0;
 	genpd->max_off_time_ns = -1;
 	genpd->max_off_time_changed = true;
+	genpd->next_wakeup = KTIME_MAX;
 	genpd->provider = NULL;
 	genpd->has_provider = false;
 	genpd->accounting_time = ktime_get_mono_fast_ns();