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Commit 4080ab08 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki Committed by Greg Kroah-Hartman
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PM-runtime: Take suppliers into account in __pm_runtime_set_status() 



If the target device has any suppliers, as reflected by device links
to them, __pm_runtime_set_status() does not take them into account,
which is not consistent with the other parts of the PM-runtime
framework and may lead to programming mistakes.

Modify __pm_runtime_set_status() to take suppliers into account by
activating them upfront if the new status is RPM_ACTIVE and
deactivating them on exit if the new status is RPM_SUSPENDED.

If the activation of one of the suppliers fails, the new status
will be RPM_SUSPENDED and the (remaining) suppliers will be
deactivated on exit (the child count of the device's parent
will be dropped too then).

Of course, adding device links locking to __pm_runtime_set_status()
means that it cannot be run fron interrupt context, so make it use
spin_lock_irq() and spin_unlock_irq() instead of spin_lock_irqsave()
and spin_unlock_irqrestore(), respectively.

Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 79a4e91d

drivers/base/power/runtime.c

+40 −5
Original line number Diff line number Diff line
@@ -1089,20 +1089,43 @@ EXPORT_SYMBOL_GPL(pm_runtime_get_if_in_use); 
 * and the device parent's counter of unsuspended children is modified to

 * reflect the new status.  If the new status is RPM_SUSPENDED, an idle

 * notification request for the parent is submitted.

 *

 * If @dev has any suppliers (as reflected by device links to them), and @status

 * is RPM_ACTIVE, they will be activated upfront and if the activation of one

 * of them fails, the status of @dev will be changed to RPM_SUSPENDED (instead

 * of the @status value) and the suppliers will be deacticated on exit.  The

 * error returned by the failing supplier activation will be returned in that

 * case.

 */

int __pm_runtime_set_status(struct device *dev, unsigned int status)

{

	struct device *parent = dev->parent;

	unsigned long flags;

	bool notify_parent = false;

	int error = 0;



	if (status != RPM_ACTIVE && status != RPM_SUSPENDED)

		return -EINVAL;



	spin_lock_irqsave(&dev->power.lock, flags);

	/*

	 * If the new status is RPM_ACTIVE, the suppliers can be activated

	 * upfront regardless of the current status, because next time

	 * rpm_put_suppliers() runs, the rpm_active refcounts of the links

	 * involved will be dropped down to one anyway.

	 */

	if (status == RPM_ACTIVE) {

		int idx = device_links_read_lock();



		error = rpm_get_suppliers(dev);

		if (error)

			status = RPM_SUSPENDED;



		device_links_read_unlock(idx);

	}



	spin_lock_irq(&dev->power.lock);



	if (!dev->power.runtime_error && !dev->power.disable_depth) {

		status = dev->power.runtime_status;

		error = -EAGAIN;

		goto out;

	}
@@ -1134,19 +1157,31 @@ int __pm_runtime_set_status(struct device *dev, unsigned int status) 


		spin_unlock(&parent->power.lock);



		if (error)

		if (error) {

			status = RPM_SUSPENDED;

			goto out;

		}

	}



 out_set:

	__update_runtime_status(dev, status);

	if (!error)

		dev->power.runtime_error = 0;



 out:

	spin_unlock_irqrestore(&dev->power.lock, flags);

	spin_unlock_irq(&dev->power.lock);



	if (notify_parent)

		pm_request_idle(parent);



	if (status == RPM_SUSPENDED) {

		int idx = device_links_read_lock();



		rpm_put_suppliers(dev);



		device_links_read_unlock(idx);

	}



	return error;

}

EXPORT_SYMBOL_GPL(__pm_runtime_set_status);