Commit bc80c2e4 authored by Rafael J. Wysocki's avatar Rafael J. Wysocki
Browse files

PM: runtime: Do not call __rpm_callback() from rpm_idle() 

Calling __rpm_callback() from rpm_idle() after adding device links
support to the former is a clear mistake.

Not only it causes rpm_idle() to carry out unnecessary actions, but it
is also against the assumption regarding the stability of PM-runtime
status across __rpm_callback() invocations, because rpm_suspend() and
rpm_resume() may run in parallel with __rpm_callback() when it is called
by rpm_idle() and the device's PM-runtime status can be updated by any
of them.

Fixes: 21d5c57b ("PM / runtime: Use device links")
Link: https://lore.kernel.org/linux-pm/36aed941-a73e-d937-2721-4f0decd61ce0@quicinc.com


Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: default avatarAdrian Hunter <adrian.hunter@intel.com>
parent 76dcd734

drivers/base/power/runtime.c

+11 −1
Original line number Diff line number Diff line
@@ -484,7 +484,17 @@ static int rpm_idle(struct device *dev, int rpmflags) 


	dev->power.idle_notification = true;



	retval = __rpm_callback(callback, dev);

	if (dev->power.irq_safe)

		spin_unlock(&dev->power.lock);

	else

		spin_unlock_irq(&dev->power.lock);



	retval = callback(dev);



	if (dev->power.irq_safe)

		spin_lock(&dev->power.lock);

	else

		spin_lock_irq(&dev->power.lock);



	dev->power.idle_notification = false;

	wake_up_all(&dev->power.wait_queue);