Merge v7.1.5linux-rolling-stable

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 74 insertions, 9 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index bd2ddf2aab50..478aa3fbf1e8 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -235,6 +235,79 @@ static void __fw_devlink_pickup_dangling_consumers(struct fwnode_handle *fwnode,
 		__fw_devlink_pickup_dangling_consumers(child, new_sup);
 }
 
+static void fw_devlink_pickup_dangling_consumers(struct device *dev)
+{
+	struct fwnode_handle *child;
+
+	guard(mutex)(&fwnode_link_lock);
+
+	fwnode_for_each_available_child_node(dev->fwnode, child)
+		__fw_devlink_pickup_dangling_consumers(child, dev->fwnode);
+	__fw_devlink_link_to_consumers(dev);
+}
+
+/**
+ * fw_devlink_refresh_fwnode - Recheck the tree under this firmware node
+ * @fwnode: The fwnode under which the fwnode tree has changed
+ *
+ * This function is mainly meant to adjust the supplier/consumer dependencies
+ * after a fwnode tree overlay has occurred.
+ */
+void fw_devlink_refresh_fwnode(struct fwnode_handle *fwnode)
+{
+	struct device *dev;
+
+	/*
+	 * Find the closest ancestor fwnode that has been converted to a device
+	 * that can bind to a driver (bus device).
+	 */
+	fwnode_handle_get(fwnode);
+	do {
+		if (fwnode_test_flag(fwnode, FWNODE_FLAG_NOT_DEVICE))
+			continue;
+
+		dev = get_dev_from_fwnode(fwnode);
+		if (!dev)
+			continue;
+
+		if (dev->bus)
+			break;
+
+		put_device(dev);
+	} while ((fwnode = fwnode_get_next_parent(fwnode)));
+
+	/*
+	 * If none of the ancestor fwnodes have (yet) been converted to a device
+	 * that can bind to a driver, there's nothing to fix up.
+	 */
+	if (!fwnode)
+		return;
+
+	WARN(device_is_bound(dev) && dev->links.status != DL_DEV_DRIVER_BOUND,
+	     "Don't multithread overlaying and probing the same device!\n");
+
+	/*
+	 * If the device has already bound to a driver, then we need to redo
+	 * some of the work that was done after the device was bound to a
+	 * driver. If the device hasn't bound to a driver, running things too
+	 * soon would incorrectly pick up consumers that it shouldn't.
+	 */
+	if (dev->links.status == DL_DEV_DRIVER_BOUND) {
+		fw_devlink_pickup_dangling_consumers(dev);
+		/*
+		 * Some of dangling consumers could have been put previously in
+		 * the deferred probe list due to the unavailability of their
+		 * suppliers. Those consumers have been picked up and some of
+		 * their suppliers links have been updated. Time to re-try their
+		 * probe sequence.
+		 */
+		driver_deferred_probe_trigger();
+	}
+
+	put_device(dev);
+	fwnode_handle_put(fwnode);
+}
+
 static DEFINE_MUTEX(device_links_lock);
 DEFINE_STATIC_SRCU(device_links_srcu);
 
@@ -1312,16 +1385,8 @@ void device_links_driver_bound(struct device *dev)
 	 * child firmware node.
 	 */
 	if (dev->fwnode && dev->fwnode->dev == dev) {
-		struct fwnode_handle *child;
-
 		fwnode_links_purge_suppliers(dev->fwnode);
-
-		guard(mutex)(&fwnode_link_lock);
-
-		fwnode_for_each_available_child_node(dev->fwnode, child)
-			__fw_devlink_pickup_dangling_consumers(child,
-							       dev->fwnode);
-		__fw_devlink_link_to_consumers(dev);
+		fw_devlink_pickup_dangling_consumers(dev);
 	}
 	device_remove_file(dev, &dev_attr_waiting_for_supplier);