Commit 3784fad9 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'pm-5.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm 

Pull power management fixes from Rafael Wysocki:
 "These fix a NULL pointer dereference in a devfreq driver and a runtime
  PM framework issue that may cause a supplier device to be suspended
  before its consumer.

  Specifics:

   - Fix NULL pointer dereference related to printing a diagnostic
     message in the exynos-bus devfreq driver (Christian Marangi)

   - Fix race condition in the runtime PM framework which in some cases
     may cause a supplier device to be suspended when its consumer is
     still active (Rafael Wysocki)"

* tag 'pm-5.19-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM / devfreq: exynos-bus: Fix NULL pointer dereference
  PM: runtime: Fix supplier device management during consumer probe
  PM: runtime: Redefine pm_runtime_release_supplier()
parents 483e4a1d fe7c758c

drivers/base/core.c

+12 −1
Original line number Diff line number Diff line
@@ -486,7 +486,18 @@ static void device_link_release_fn(struct work_struct *work) 
	/* Ensure that all references to the link object have been dropped. */

	device_link_synchronize_removal();



	pm_runtime_release_supplier(link, true);

	pm_runtime_release_supplier(link);

	/*

	 * If supplier_preactivated is set, the link has been dropped between

	 * the pm_runtime_get_suppliers() and pm_runtime_put_suppliers() calls

	 * in __driver_probe_device().  In that case, drop the supplier's

	 * PM-runtime usage counter to remove the reference taken by

	 * pm_runtime_get_suppliers().

	 */

	if (link->supplier_preactivated)

		pm_runtime_put_noidle(link->supplier);



	pm_request_idle(link->supplier);



	put_device(link->consumer);

	put_device(link->supplier);

drivers/base/power/runtime.c

+10 −24
Original line number Diff line number Diff line
@@ -308,13 +308,10 @@ static int rpm_get_suppliers(struct device *dev) 
/**

 * pm_runtime_release_supplier - Drop references to device link's supplier.

 * @link: Target device link.

 * @check_idle: Whether or not to check if the supplier device is idle.

 *

 * Drop all runtime PM references associated with @link to its supplier device

 * and if @check_idle is set, check if that device is idle (and so it can be

 * suspended).

 * Drop all runtime PM references associated with @link to its supplier device.

 */

void pm_runtime_release_supplier(struct device_link *link, bool check_idle)

void pm_runtime_release_supplier(struct device_link *link)

{

	struct device *supplier = link->supplier;
@@ -327,9 +324,6 @@ void pm_runtime_release_supplier(struct device_link *link, bool check_idle) 
	while (refcount_dec_not_one(&link->rpm_active) &&

	       atomic_read(&supplier->power.usage_count) > 0)

		pm_runtime_put_noidle(supplier);



	if (check_idle)

		pm_request_idle(supplier);

}



static void __rpm_put_suppliers(struct device *dev, bool try_to_suspend)
@@ -337,8 +331,11 @@ static void __rpm_put_suppliers(struct device *dev, bool try_to_suspend) 
	struct device_link *link;



	list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,

				device_links_read_lock_held())

		pm_runtime_release_supplier(link, try_to_suspend);

				device_links_read_lock_held()) {

		pm_runtime_release_supplier(link);

		if (try_to_suspend)

			pm_request_idle(link->supplier);

	}

}



static void rpm_put_suppliers(struct device *dev)
@@ -1771,7 +1768,6 @@ void pm_runtime_get_suppliers(struct device *dev) 
		if (link->flags & DL_FLAG_PM_RUNTIME) {

			link->supplier_preactivated = true;

			pm_runtime_get_sync(link->supplier);

			refcount_inc(&link->rpm_active);

		}



	device_links_read_unlock(idx);
@@ -1791,18 +1787,7 @@ void pm_runtime_put_suppliers(struct device *dev) 
	list_for_each_entry_rcu(link, &dev->links.suppliers, c_node,

				device_links_read_lock_held())

		if (link->supplier_preactivated) {

			bool put;



			link->supplier_preactivated = false;



			spin_lock_irq(&dev->power.lock);



			put = pm_runtime_status_suspended(dev) &&

			      refcount_dec_not_one(&link->rpm_active);



			spin_unlock_irq(&dev->power.lock);



			if (put)

			pm_runtime_put(link->supplier);

		}
@@ -1838,7 +1823,8 @@ void pm_runtime_drop_link(struct device_link *link) 
		return;



	pm_runtime_drop_link_count(link->consumer);

	pm_runtime_release_supplier(link, true);

	pm_runtime_release_supplier(link);

	pm_request_idle(link->supplier);

}



static bool pm_runtime_need_not_resume(struct device *dev)

drivers/devfreq/exynos-bus.c

+3 −3
Original line number Diff line number Diff line
@@ -447,9 +447,9 @@ static int exynos_bus_probe(struct platform_device *pdev) 
		}

	}



	max_state = bus->devfreq->profile->max_state;

	min_freq = (bus->devfreq->profile->freq_table[0] / 1000);

	max_freq = (bus->devfreq->profile->freq_table[max_state - 1] / 1000);

	max_state = bus->devfreq->max_state;

	min_freq = (bus->devfreq->freq_table[0] / 1000);

	max_freq = (bus->devfreq->freq_table[max_state - 1] / 1000);

	pr_info("exynos-bus: new bus device registered: %s (%6ld KHz ~ %6ld KHz)\n",

			dev_name(dev), min_freq, max_freq);

include/linux/pm_runtime.h

+2 −3
Original line number Diff line number Diff line
@@ -88,7 +88,7 @@ extern void pm_runtime_get_suppliers(struct device *dev); 
extern void pm_runtime_put_suppliers(struct device *dev);

extern void pm_runtime_new_link(struct device *dev);

extern void pm_runtime_drop_link(struct device_link *link);

extern void pm_runtime_release_supplier(struct device_link *link, bool check_idle);

extern void pm_runtime_release_supplier(struct device_link *link);



extern int devm_pm_runtime_enable(struct device *dev);
@@ -314,8 +314,7 @@ static inline void pm_runtime_get_suppliers(struct device *dev) {} 
static inline void pm_runtime_put_suppliers(struct device *dev) {}

static inline void pm_runtime_new_link(struct device *dev) {}

static inline void pm_runtime_drop_link(struct device_link *link) {}

static inline void pm_runtime_release_supplier(struct device_link *link,

					       bool check_idle) {}

static inline void pm_runtime_release_supplier(struct device_link *link) {}



#endif /* !CONFIG_PM */