Commit e9825d1c authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'pm-7.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm 

Pull power management fixes from Rafael Wysocki:
 "These fix an idle loop issue exposed by recent changes and a race
  condition related to device removal in the runtime PM core code:

   - Consolidate the handling of two special cases in the idle loop that
     occur when only one CPU idle state is present (Rafael Wysocki)

   - Fix a race condition related to device removal in the runtime PM
     core code that may cause a stale device object pointer to be
     dereferenced (Bart Van Assche)"

* tag 'pm-7.0-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM: runtime: Fix a race condition related to device removal
  sched: idle: Consolidate the handling of two special cases
parents d107dc8c 96333706

drivers/base/power/runtime.c

+1 −0
Original line number Diff line number Diff line
@@ -1895,6 +1895,7 @@ void pm_runtime_reinit(struct device *dev) 
void pm_runtime_remove(struct device *dev)

{

	__pm_runtime_disable(dev, false);

	flush_work(&dev->power.work);

	pm_runtime_reinit(dev);

}

kernel/sched/idle.c

+21 −9
Original line number Diff line number Diff line
@@ -161,6 +161,14 @@ static int call_cpuidle(struct cpuidle_driver *drv, struct cpuidle_device *dev, 
	return cpuidle_enter(drv, dev, next_state);

}



static void idle_call_stop_or_retain_tick(bool stop_tick)

{

	if (stop_tick || tick_nohz_tick_stopped())

		tick_nohz_idle_stop_tick();

	else

		tick_nohz_idle_retain_tick();

}



/**

 * cpuidle_idle_call - the main idle function

 *
@@ -170,7 +178,7 @@ static int call_cpuidle(struct cpuidle_driver *drv, struct cpuidle_device *dev, 
 * set, and it returns with polling set.  If it ever stops polling, it

 * must clear the polling bit.

 */

static void cpuidle_idle_call(void)

static void cpuidle_idle_call(bool stop_tick)

{

	struct cpuidle_device *dev = cpuidle_get_device();

	struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
@@ -186,7 +194,7 @@ static void cpuidle_idle_call(void) 
	}



	if (cpuidle_not_available(drv, dev)) {

		tick_nohz_idle_stop_tick();

		idle_call_stop_or_retain_tick(stop_tick);



		default_idle_call();

		goto exit_idle;
@@ -222,17 +230,19 @@ static void cpuidle_idle_call(void) 
		next_state = cpuidle_find_deepest_state(drv, dev, max_latency_ns);

		call_cpuidle(drv, dev, next_state);

	} else if (drv->state_count > 1) {

		bool stop_tick = true;

		/*

		 * stop_tick is expected to be true by default by cpuidle

		 * governors, which allows them to select idle states with

		 * target residency above the tick period length.

		 */

		stop_tick = true;



		/*

		 * Ask the cpuidle framework to choose a convenient idle state.

		 */

		next_state = cpuidle_select(drv, dev, &stop_tick);



		if (stop_tick || tick_nohz_tick_stopped())

			tick_nohz_idle_stop_tick();

		else

			tick_nohz_idle_retain_tick();

		idle_call_stop_or_retain_tick(stop_tick);



		entered_state = call_cpuidle(drv, dev, next_state);

		/*
@@ -240,7 +250,7 @@ static void cpuidle_idle_call(void) 
		 */

		cpuidle_reflect(dev, entered_state);

	} else {

		tick_nohz_idle_retain_tick();

		idle_call_stop_or_retain_tick(stop_tick);



		/*

		 * If there is only a single idle state (or none), there is
@@ -268,6 +278,7 @@ static void cpuidle_idle_call(void) 
static void do_idle(void)

{

	int cpu = smp_processor_id();

	bool got_tick = false;



	/*

	 * Check if we need to update blocked load
@@ -338,8 +349,9 @@ static void do_idle(void) 
			tick_nohz_idle_restart_tick();

			cpu_idle_poll();

		} else {

			cpuidle_idle_call();

			cpuidle_idle_call(got_tick);

		}

		got_tick = tick_nohz_idle_got_tick();

		arch_cpu_idle_exit();

	}