Commit ec857209 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'pm-5.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm 

Pull power management fixes from Rafael Wysocki:
 "Revert two problematic commits.

  Specifics:

   - Revert ACPI PM commit that attempted to improve reboot handling on
     some systems, but it caused other systems to panic() during reboot
     (Josef Bacik)

   - Revert PM-runtime commit that attempted to improve the handling of
     suppliers during PM-runtime suspend of a consumer device, but it
     introduced a race condition potentially leading to unexpected
     behavior (Rafael Wysocki)"

* tag 'pm-5.12-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  Revert "PM: runtime: Update device status before letting suppliers suspend"
  Revert "PM: ACPI: reboot: Use S5 for reboot"
parents 65a10374 49cb71a7

drivers/base/power/runtime.c

+25 −37
Original line number Diff line number Diff line
@@ -325,22 +325,22 @@ static void rpm_put_suppliers(struct device *dev) 
static int __rpm_callback(int (*cb)(struct device *), struct device *dev)

	__releases(&dev->power.lock) __acquires(&dev->power.lock)

{

	bool use_links = dev->power.links_count > 0;

	bool get = false;

	int retval, idx;

	bool put;

	bool use_links = dev->power.links_count > 0;



	if (dev->power.irq_safe) {

		spin_unlock(&dev->power.lock);

	} else if (!use_links) {

		spin_unlock_irq(&dev->power.lock);

	} else {

		get = dev->power.runtime_status == RPM_RESUMING;



		spin_unlock_irq(&dev->power.lock);



		/* Resume suppliers if necessary. */

		if (get) {

		/*

		 * Resume suppliers if necessary.

		 *

		 * The device's runtime PM status cannot change until this

		 * routine returns, so it is safe to read the status outside of

		 * the lock.

		 */

		if (use_links && dev->power.runtime_status == RPM_RESUMING) {

			idx = device_links_read_lock();



			retval = rpm_get_suppliers(dev);
@@ -355,36 +355,24 @@ static int __rpm_callback(int (*cb)(struct device *), struct device *dev) 


	if (dev->power.irq_safe) {

		spin_lock(&dev->power.lock);

		return retval;

	}



	spin_lock_irq(&dev->power.lock);



	if (!use_links)

		return retval;



	} else {

		/*

	 * If the device is suspending and the callback has returned success,

	 * drop the usage counters of the suppliers that have been reference

	 * counted on its resume.

		 * If the device is suspending and the callback has returned

		 * success, drop the usage counters of the suppliers that have

		 * been reference counted on its resume.

		 *

	 * Do that if the resume fails too.

		 * Do that if resume fails too.

		 */

	put = dev->power.runtime_status == RPM_SUSPENDING && !retval;

	if (put)

		__update_runtime_status(dev, RPM_SUSPENDED);

	else

		put = get && retval;



	if (put) {

		spin_unlock_irq(&dev->power.lock);



		if (use_links

		    && ((dev->power.runtime_status == RPM_SUSPENDING && !retval)

		    || (dev->power.runtime_status == RPM_RESUMING && retval))) {

			idx = device_links_read_lock();



 fail:

			rpm_put_suppliers(dev);



			device_links_read_unlock(idx);

		}



		spin_lock_irq(&dev->power.lock);

	}

kernel/reboot.c

+0 −2
Original line number Diff line number Diff line
@@ -244,8 +244,6 @@ void migrate_to_reboot_cpu(void) 
void kernel_restart(char *cmd)

{

	kernel_restart_prepare(cmd);

	if (pm_power_off_prepare)

		pm_power_off_prepare();

	migrate_to_reboot_cpu();

	syscore_shutdown();

	if (!cmd)