patch "driver core: Add missing dev->bus->need_parent_lock checks" added to driver-core-testing

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

    driver core: Add missing dev->bus->need_parent_lock checks

to my driver-core git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core.git
in the driver-core-testing branch.

The patch will show up in the next release of the linux-next tree (usually sometime within the next 24 hours during the week.)

The patch will be merged to the driver-core-next branch sometime soon, after it passes testing, and the merge window is open.

If you have any questions about this process, please let me know.

From: "Rafael J. Wysocki" <[email protected]>
Date: Thu, 13 Dec 2018 19:27:47 +0100
Subject: driver core: Add missing dev->bus->need_parent_lock checks

__device_release_driver() has to check dev->bus->need_parent_lock before dropping the parent lock and acquiring it again as it may attempt to drop a lock that hasn't been acquired or lock a device that shouldn't be locked and create a lock imbalance.

---
 drivers/base/dd.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

index 88713f182086..8ac10af17c00 100644
@@ -933,11 +933,11 @@ static void __device_release_driver(struct device *dev, struct device *parent)
 	if (drv) {
 		while (device_links_busy(dev)) {
 			device_unlock(dev);
-			if (parent)
+			if (parent && dev->bus->need_parent_lock)
 				device_unlock(parent);
 
 			device_links_unbind_consumers(dev);
-			if (parent)
+			if (parent && dev->bus->need_parent_lock)
 				device_lock(parent);
 
 			device_lock(dev);

2.20.1