Patch "PM: core: Fix device_pm_check_callbacks()" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

PM: core: Fix device_pm_check_callbacks()

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
pm-core-fix-device_pm_check_callbacks.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: "Rafael J. Wysocki" <[email protected]>
Date: Tue, 19 Sep 2017 02:22:39 +0200
Subject: PM: core: Fix device_pm_check_callbacks()

From: Rafael J. Wysocki <[email protected]>

commit 157c460e10cb6eca29ccbd0f023db159d0c55ec7 upstream.

The device_pm_check_callbacks() function doesn't check legacy ->suspend and ->resume callback pointers under the device's bus type, class and driver, so in some cases it may set the no_pm_callbacks flag for the device incorrectly and then the callbacks may be skipped during system suspend/resume, which shouldn't happen.

---
 drivers/base/power/main.c |    9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

@@ -1757,10 +1757,13 @@ void device_pm_check_callbacks(struct de
 {
 	spin_lock_irq(&dev->power.lock);
 	dev->power.no_pm_callbacks =
-		(!dev->bus || pm_ops_is_empty(dev->bus->pm)) &&
-		(!dev->class || pm_ops_is_empty(dev->class->pm)) &&
+		(!dev->bus || (pm_ops_is_empty(dev->bus->pm) &&
+		 !dev->bus->suspend && !dev->bus->resume)) &&
+		(!dev->class || (pm_ops_is_empty(dev->class->pm) &&
+		 !dev->class->suspend && !dev->class->resume)) &&
 		(!dev->type || pm_ops_is_empty(dev->type->pm)) &&
 		(!dev->pm_domain || pm_ops_is_empty(&dev->pm_domain->ops)) &&
-		(!dev->driver || pm_ops_is_empty(dev->driver->pm));
+		(!dev->driver || (pm_ops_is_empty(dev->driver->pm) &&
+		 !dev->driver->suspend && !dev->driver->resume));
 	spin_unlock_irq(&dev->power.lock);
 }

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/pm-core-fix-device_pm_check_callbacks.patch