Merge tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core

Pull driver core updates from Greg KH:
 "Here is the large set of driver core changes for 6.3-rc1.

  There's a lot of changes this development cycle, most of the work
  falls into two different categories:

   - fw_devlink fixes and updates. This has gone through numerous review
     cycles and lots of review and testing by lots of different devices.
     Hopefully all should be good now, and Saravana will be keeping a
     watch for any potential regression on odd embedded systems.

   - driver core changes to work to make struct bus_type able to be
     moved into read-only memory (i.e. const) The recent work with Rust
     has pointed out a number of areas in the driver core where we are
     passing around and working with structures that really do not have
     to be dynamic at all, and they should be able to be read-only
     making things safer overall. This is the contuation of that work
     (started last release with kobject changes) in moving struct
     bus_type to be constant. We didn't quite make it for this release,
     but the remaining patches will be finished up for the release after
     this one, but the groundwork has been laid for this effort.

  Other than that we have in here:

   - debugfs memory leak fixes in some subsystems

   - error path cleanups and fixes for some never-able-to-be-hit
     codepaths.

   - cacheinfo rework and fixes

   - Other tiny fixes, full details are in the shortlog

  All of these have been in linux-next for a while with no reported
  problems"

[ Geert Uytterhoeven points out that that last sentence isn't true, and
  that there's a pending report that has a fix that is queued up - Linus ]

* tag 'driver-core-6.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (124 commits)
  debugfs: drop inline constant formatting for ERR_PTR(-ERROR)
  OPP: fix error checking in opp_migrate_dentry()
  debugfs: update comment of debugfs_rename()
  i3c: fix device.h kernel-doc warnings
  dma-mapping: no need to pass a bus_type into get_arch_dma_ops()
  driver core: class: move EXPORT_SYMBOL_GPL() lines to the correct place
  Revert "driver core: add error handling for devtmpfs_create_node()"
  Revert "devtmpfs: add debug info to handle()"
  Revert "devtmpfs: remove return value of devtmpfs_delete_node()"
  driver core: cpu: don't hand-override the uevent bus_type callback.
  devtmpfs: remove return value of devtmpfs_delete_node()
  devtmpfs: add debug info to handle()
  driver core: add error handling for devtmpfs_create_node()
  driver core: bus: update my copyright notice
  driver core: bus: add bus_get_dev_root() function
  driver core: bus: constify bus_unregister()
  driver core: bus: constify some internal functions
  driver core: bus: constify bus_get_kset()
  driver core: bus: constify bus_register/unregister_notifier()
  driver core: remove private pointer from struct bus_type
  ...

1 files changed, 319 insertions, 170 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index bb36aca8d1b7..e54a10b5dbd7 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -54,11 +54,12 @@ static LIST_HEAD(deferred_sync);
 static unsigned int defer_sync_state_count = 1;
 static DEFINE_MUTEX(fwnode_link_lock);
 static bool fw_devlink_is_permissive(void);
+static void __fw_devlink_link_to_consumers(struct device *dev);
 static bool fw_devlink_drv_reg_done;
 static bool fw_devlink_best_effort;
 
 /**
- * fwnode_link_add - Create a link between two fwnode_handles.
+ * __fwnode_link_add - Create a link between two fwnode_handles.
  * @con: Consumer end of the link.
  * @sup: Supplier end of the link.
  *
@@ -74,35 +75,42 @@ static bool fw_devlink_best_effort;
  * Attempts to create duplicate links between the same pair of fwnode handles
  * are ignored and there is no reference counting.
  */
-int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup)
+static int __fwnode_link_add(struct fwnode_handle *con,
+			     struct fwnode_handle *sup, u8 flags)
 {
 	struct fwnode_link *link;
-	int ret = 0;
-
-	mutex_lock(&fwnode_link_lock);
 
 	list_for_each_entry(link, &sup->consumers, s_hook)
-		if (link->consumer == con)
-			goto out;
+		if (link->consumer == con) {
+			link->flags |= flags;
+			return 0;
+		}
 
 	link = kzalloc(sizeof(*link), GFP_KERNEL);
-	if (!link) {
-		ret = -ENOMEM;
-		goto out;
-	}
+	if (!link)
+		return -ENOMEM;
 
 	link->supplier = sup;
 	INIT_LIST_HEAD(&link->s_hook);
 	link->consumer = con;
 	INIT_LIST_HEAD(&link->c_hook);
+	link->flags = flags;
 
 	list_add(&link->s_hook, &sup->consumers);
 	list_add(&link->c_hook, &con->suppliers);
 	pr_debug("%pfwP Linked as a fwnode consumer to %pfwP\n",
 		 con, sup);
-out:
-	mutex_unlock(&fwnode_link_lock);
 
+	return 0;
+}
+
+int fwnode_link_add(struct fwnode_handle *con, struct fwnode_handle *sup)
+{
+	int ret;
+
+	mutex_lock(&fwnode_link_lock);
+	ret = __fwnode_link_add(con, sup, 0);
+	mutex_unlock(&fwnode_link_lock);
 	return ret;
 }
 
@@ -122,6 +130,19 @@ static void __fwnode_link_del(struct fwnode_link *link)
 }
 
 /**
+ * __fwnode_link_cycle - Mark a fwnode link as being part of a cycle.
+ * @link: the fwnode_link to be marked
+ *
+ * The fwnode_link_lock needs to be held when this function is called.
+ */
+static void __fwnode_link_cycle(struct fwnode_link *link)
+{
+	pr_debug("%pfwf: Relaxing link with %pfwf\n",
+		 link->consumer, link->supplier);
+	link->flags |= FWLINK_FLAG_CYCLE;
+}
+
+/**
  * fwnode_links_purge_suppliers - Delete all supplier links of fwnode_handle.
  * @fwnode: fwnode whose supplier links need to be deleted
  *
@@ -181,6 +202,51 @@ void fw_devlink_purge_absent_suppliers(struct fwnode_handle *fwnode)
 }
 EXPORT_SYMBOL_GPL(fw_devlink_purge_absent_suppliers);
 
+/**
+ * __fwnode_links_move_consumers - Move consumer from @from to @to fwnode_handle
+ * @from: move consumers away from this fwnode
+ * @to: move consumers to this fwnode
+ *
+ * Move all consumer links from @from fwnode to @to fwnode.
+ */
+static void __fwnode_links_move_consumers(struct fwnode_handle *from,
+					  struct fwnode_handle *to)
+{
+	struct fwnode_link *link, *tmp;
+
+	list_for_each_entry_safe(link, tmp, &from->consumers, s_hook) {
+		__fwnode_link_add(link->consumer, to, link->flags);
+		__fwnode_link_del(link);
+	}
+}
+
+/**
+ * __fw_devlink_pickup_dangling_consumers - Pick up dangling consumers
+ * @fwnode: fwnode from which to pick up dangling consumers
+ * @new_sup: fwnode of new supplier
+ *
+ * If the @fwnode has a corresponding struct device and the device supports
+ * probing (that is, added to a bus), then we want to let fw_devlink create
+ * MANAGED device links to this device, so leave @fwnode and its descendant's
+ * fwnode links alone.
+ *
+ * Otherwise, move its consumers to the new supplier @new_sup.
+ */
+static void __fw_devlink_pickup_dangling_consumers(struct fwnode_handle *fwnode,
+						   struct fwnode_handle *new_sup)
+{
+	struct fwnode_handle *child;
+
+	if (fwnode->dev && fwnode->dev->bus)
+		return;
+
+	fwnode->flags |= FWNODE_FLAG_NOT_DEVICE;
+	__fwnode_links_move_consumers(fwnode, new_sup);
+
+	fwnode_for_each_available_child_node(fwnode, child)
+		__fw_devlink_pickup_dangling_consumers(child, new_sup);
+}
+
 static DEFINE_MUTEX(device_links_lock);
 DEFINE_STATIC_SRCU(device_links_srcu);
 
@@ -230,6 +296,12 @@ static bool device_is_ancestor(struct device *dev, struct device *target)
 	return false;
 }
 
+static inline bool device_link_flag_is_sync_state_only(u32 flags)
+{
+	return (flags & ~(DL_FLAG_INFERRED | DL_FLAG_CYCLE)) ==
+		(DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED);
+}
+
 /**
  * device_is_dependent - Check if one device depends on another one
  * @dev: Device to check dependencies for.
@@ -256,8 +328,7 @@ int device_is_dependent(struct device *dev, void *target)
 		return ret;
 
 	list_for_each_entry(link, &dev->links.consumers, s_node) {
-		if ((link->flags & ~DL_FLAG_INFERRED) ==
-		    (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
+		if (device_link_flag_is_sync_state_only(link->flags))
 			continue;
 
 		if (link->consumer == target)
@@ -330,8 +401,7 @@ static int device_reorder_to_tail(struct device *dev, void *not_used)
 
 	device_for_each_child(dev, NULL, device_reorder_to_tail);
 	list_for_each_entry(link, &dev->links.consumers, s_node) {
-		if ((link->flags & ~DL_FLAG_INFERRED) ==
-		    (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
+		if (device_link_flag_is_sync_state_only(link->flags))
 			continue;
 		device_reorder_to_tail(link->consumer, NULL);
 	}
@@ -592,7 +662,8 @@ postcore_initcall(devlink_class_init);
 			       DL_FLAG_AUTOREMOVE_SUPPLIER | \
 			       DL_FLAG_AUTOPROBE_CONSUMER  | \
 			       DL_FLAG_SYNC_STATE_ONLY | \
-			       DL_FLAG_INFERRED)
+			       DL_FLAG_INFERRED | \
+			       DL_FLAG_CYCLE)
 
 #define DL_ADD_VALID_FLAGS (DL_MANAGED_LINK_FLAGS | DL_FLAG_STATELESS | \
 			    DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE)
@@ -661,8 +732,6 @@ struct device_link *device_link_add(struct device *consumer,
 	if (!consumer || !supplier || consumer == supplier ||
 	    flags & ~DL_ADD_VALID_FLAGS ||
 	    (flags & DL_FLAG_STATELESS && flags & DL_MANAGED_LINK_FLAGS) ||
-	    (flags & DL_FLAG_SYNC_STATE_ONLY &&
-	     (flags & ~DL_FLAG_INFERRED) != DL_FLAG_SYNC_STATE_ONLY) ||
 	    (flags & DL_FLAG_AUTOPROBE_CONSUMER &&
 	     flags & (DL_FLAG_AUTOREMOVE_CONSUMER |
 		      DL_FLAG_AUTOREMOVE_SUPPLIER)))
@@ -678,6 +747,10 @@ struct device_link *device_link_add(struct device *consumer,
 	if (!(flags & DL_FLAG_STATELESS))
 		flags |= DL_FLAG_MANAGED;
 
+	if (flags & DL_FLAG_SYNC_STATE_ONLY &&
+	    !device_link_flag_is_sync_state_only(flags))
+		return NULL;
+
 	device_links_write_lock();
 	device_pm_lock();
 
@@ -942,6 +1015,21 @@ static bool dev_is_best_effort(struct device *dev)
 		(dev->fwnode && (dev->fwnode->flags & FWNODE_FLAG_BEST_EFFORT));
 }
 
+static struct fwnode_handle *fwnode_links_check_suppliers(
+						struct fwnode_handle *fwnode)
+{
+	struct fwnode_link *link;
+
+	if (!fwnode || fw_devlink_is_permissive())
+		return NULL;
+
+	list_for_each_entry(link, &fwnode->suppliers, c_hook)
+		if (!(link->flags & FWLINK_FLAG_CYCLE))
+			return link->supplier;
+
+	return NULL;
+}
+
 /**
  * device_links_check_suppliers - Check presence of supplier drivers.
  * @dev: Consumer device.
@@ -969,11 +1057,8 @@ int device_links_check_suppliers(struct device *dev)
 	 * probe.
 	 */
 	mutex_lock(&fwnode_link_lock);
-	if (dev->fwnode && !list_empty(&dev->fwnode->suppliers) &&
-	    !fw_devlink_is_permissive()) {
-		sup_fw = list_first_entry(&dev->fwnode->suppliers,
-					  struct fwnode_link,
-					  c_hook)->supplier;
+	sup_fw = fwnode_links_check_suppliers(dev->fwnode);
+	if (sup_fw) {
 		if (!dev_is_best_effort(dev)) {
 			fwnode_ret = -EPROBE_DEFER;
 			dev_err_probe(dev, -EPROBE_DEFER,
@@ -1162,7 +1247,9 @@ static ssize_t waiting_for_supplier_show(struct device *dev,
 	bool val;
 
 	device_lock(dev);
-	val = !list_empty(&dev->fwnode->suppliers);
+	mutex_lock(&fwnode_link_lock);
+	val = !!fwnode_links_check_suppliers(dev->fwnode);
+	mutex_unlock(&fwnode_link_lock);
 	device_unlock(dev);
 	return sysfs_emit(buf, "%u\n", val);
 }
@@ -1225,16 +1312,23 @@ void device_links_driver_bound(struct device *dev)
 	 * them. So, fw_devlink no longer needs to create device links to any
 	 * of the device's suppliers.
 	 *
-	 * Also, if a child firmware node of this bound device is not added as
-	 * a device by now, assume it is never going to be added and make sure
-	 * other devices don't defer probe indefinitely by waiting for such a
-	 * child device.
+	 * Also, if a child firmware node of this bound device is not added as a
+	 * device by now, assume it is never going to be added. Make this bound
+	 * device the fallback supplier to the dangling consumers of the child
+	 * firmware node because this bound device is probably implementing the
+	 * child firmware node functionality and we don't want the dangling
+	 * consumers to defer probe indefinitely waiting for a device for the
+	 * child firmware node.
 	 */
 	if (dev->fwnode && dev->fwnode->dev == dev) {
 		struct fwnode_handle *child;
 		fwnode_links_purge_suppliers(dev->fwnode);
+		mutex_lock(&fwnode_link_lock);
 		fwnode_for_each_available_child_node(dev->fwnode, child)
-			fw_devlink_purge_absent_suppliers(child);
+			__fw_devlink_pickup_dangling_consumers(child,
+							       dev->fwnode);
+		__fw_devlink_link_to_consumers(dev);
+		mutex_unlock(&fwnode_link_lock);
 	}
 	device_remove_file(dev, &dev_attr_waiting_for_supplier);
 
@@ -1591,8 +1685,11 @@ static int __init fw_devlink_strict_setup(char *arg)
 }
 early_param("fw_devlink.strict", fw_devlink_strict_setup);
 
-u32 fw_devlink_get_flags(void)
+static inline u32 fw_devlink_get_flags(u8 fwlink_flags)
 {
+	if (fwlink_flags & FWLINK_FLAG_CYCLE)
+		return FW_DEVLINK_FLAGS_PERMISSIVE | DL_FLAG_CYCLE;
+
 	return fw_devlink_flags;
 }
 
@@ -1630,7 +1727,7 @@ static void fw_devlink_relax_link(struct device_link *link)
 	if (!(link->flags & DL_FLAG_INFERRED))
 		return;
 
-	if (link->flags == (DL_FLAG_MANAGED | FW_DEVLINK_FLAGS_PERMISSIVE))
+	if (device_link_flag_is_sync_state_only(link->flags))
 		return;
 
 	pm_runtime_drop_link(link);
@@ -1727,44 +1824,138 @@ static void fw_devlink_unblock_consumers(struct device *dev)
 	device_links_write_unlock();
 }
 
+
+static bool fwnode_init_without_drv(struct fwnode_handle *fwnode)
+{
+	struct device *dev;
+	bool ret;
+
+	if (!(fwnode->flags & FWNODE_FLAG_INITIALIZED))
+		return false;
+
+	dev = get_dev_from_fwnode(fwnode);
+	ret = !dev || dev->links.status == DL_DEV_NO_DRIVER;
+	put_device(dev);
+
+	return ret;
+}
+
+static bool fwnode_ancestor_init_without_drv(struct fwnode_handle *fwnode)
+{
+	struct fwnode_handle *parent;
+
+	fwnode_for_each_parent_node(fwnode, parent) {
+		if (fwnode_init_without_drv(parent)) {
+			fwnode_handle_put(parent);
+			return true;
+		}
+	}
+
+	return false;
+}
+
 /**
- * fw_devlink_relax_cycle - Convert cyclic links to SYNC_STATE_ONLY links
- * @con: Device to check dependencies for.
- * @sup: Device to check against.
- *
- * Check if @sup depends on @con or any device dependent on it (its child or
- * its consumer etc).  When such a cyclic dependency is found, convert all
- * device links created solely by fw_devlink into SYNC_STATE_ONLY device links.
- * This is the equivalent of doing fw_devlink=permissive just between the
- * devices in the cycle. We need to do this because, at this point, fw_devlink
- * can't tell which of these dependencies is not a real dependency.
- *
- * Return 1 if a cycle is found. Otherwise, return 0.
+ * __fw_devlink_relax_cycles - Relax and mark dependency cycles.
+ * @con: Potential consumer device.
+ * @sup_handle: Potential supplier's fwnode.
+ *
+ * Needs to be called with fwnode_lock and device link lock held.
+ *
+ * Check if @sup_handle or any of its ancestors or suppliers direct/indirectly
+ * depend on @con. This function can detect multiple cyles between @sup_handle
+ * and @con. When such dependency cycles are found, convert all device links
+ * created solely by fw_devlink into SYNC_STATE_ONLY device links. Also, mark
+ * all fwnode links in the cycle with FWLINK_FLAG_CYCLE so that when they are
+ * converted into a device link in the future, they are created as
+ * SYNC_STATE_ONLY device links. This is the equivalent of doing
+ * fw_devlink=permissive just between the devices in the cycle. We need to do
+ * this because, at this point, fw_devlink can't tell which of these
+ * dependencies is not a real dependency.
+ *
+ * Return true if one or more cycles were found. Otherwise, return false.
  */
-static int fw_devlink_relax_cycle(struct device *con, void *sup)
+static bool __fw_devlink_relax_cycles(struct device *con,
+				 struct fwnode_handle *sup_handle)
 {
-	struct device_link *link;
-	int ret;
+	struct device *sup_dev = NULL, *par_dev = NULL;
+	struct fwnode_link *link;
+	struct device_link *dev_link;
+	bool ret = false;
 
-	if (con == sup)
-		return 1;
+	if (!sup_handle)
+		return false;
 
-	ret = device_for_each_child(con, sup, fw_devlink_relax_cycle);
-	if (ret)
-		return ret;
+	/*
+	 * We aren't trying to find all cycles. Just a cycle between con and
+	 * sup_handle.
+	 */
+	if (sup_handle->flags & FWNODE_FLAG_VISITED)
+		return false;
 
-	list_for_each_entry(link, &con->links.consumers, s_node) {
-		if ((link->flags & ~DL_FLAG_INFERRED) ==
-		    (DL_FLAG_SYNC_STATE_ONLY | DL_FLAG_MANAGED))
-			continue;
+	sup_handle->flags |= FWNODE_FLAG_VISITED;
 
-		if (!fw_devlink_relax_cycle(link->consumer, sup))
-			continue;
+	sup_dev = get_dev_from_fwnode(sup_handle);
 
-		ret = 1;
+	/* Termination condition. */
+	if (sup_dev == con) {
+		ret = true;
+		goto out;
+	}
 
-		fw_devlink_relax_link(link);
+	/*
+	 * If sup_dev is bound to a driver and @con hasn't started binding to a
+	 * driver, sup_dev can't be a consumer of @con. So, no need to check
+	 * further.
+	 */
+	if (sup_dev && sup_dev->links.status ==  DL_DEV_DRIVER_BOUND &&
+	    con->links.status == DL_DEV_NO_DRIVER) {
+		ret = false;
+		goto out;
+	}
+
+	list_for_each_entry(link, &sup_handle->suppliers, c_hook) {
+		if (__fw_devlink_relax_cycles(con, link->supplier)) {
+			__fwnode_link_cycle(link);
+			ret = true;
+		}
 	}
+
+	/*
+	 * Give priority to device parent over fwnode parent to account for any
+	 * quirks in how fwnodes are converted to devices.
+	 */
+	if (sup_dev)
+		par_dev = get_device(sup_dev->parent);
+	else
+		par_dev = fwnode_get_next_parent_dev(sup_handle);
+
+	if (par_dev && __fw_devlink_relax_cycles(con, par_dev->fwnode))
+		ret = true;
+
+	if (!sup_dev)
+		goto out;
+
+	list_for_each_entry(dev_link, &sup_dev->links.suppliers, c_node) {
+		/*
+		 * Ignore a SYNC_STATE_ONLY flag only if it wasn't marked as
+		 * such due to a cycle.
+		 */
+		if (device_link_flag_is_sync_state_only(dev_link->flags) &&
+		    !(dev_link->flags & DL_FLAG_CYCLE))
+			continue;
+
+		if (__fw_devlink_relax_cycles(con,
+					      dev_link->supplier->fwnode)) {
+			fw_devlink_relax_link(dev_link);
+			dev_link->flags |= DL_FLAG_CYCLE;
+			ret = true;
+		}
+	}
+
+out:
+	sup_handle->flags &= ~FWNODE_FLAG_VISITED;
+	put_device(sup_dev);
+	put_device(par_dev);
 	return ret;
 }
 
@@ -1772,7 +1963,7 @@ static int fw_devlink_relax_cycle(struct device *con, void *sup)
  * fw_devlink_create_devlink - Create a device link from a consumer to fwnode
  * @con: consumer device for the device link
  * @sup_handle: fwnode handle of supplier
- * @flags: devlink flags
+ * @link: fwnode link that's being converted to a device link
  *
  * This function will try to create a device link between the consumer device
  * @con and the supplier device represented by @sup_handle.
@@ -1789,10 +1980,17 @@ static int fw_devlink_relax_cycle(struct device *con, void *sup)
  *  possible to do that in the future
  */
 static int fw_devlink_create_devlink(struct device *con,
-				     struct fwnode_handle *sup_handle, u32 flags)
+				     struct fwnode_handle *sup_handle,
+				     struct fwnode_link *link)
 {
 	struct device *sup_dev;
 	int ret = 0;
+	u32 flags;
+
+	if (con->fwnode == link->consumer)
+		flags = fw_devlink_get_flags(link->flags);
+	else
+		flags = FW_DEVLINK_FLAGS_PERMISSIVE;
 
 	/*
 	 * In some cases, a device P might also be a supplier to its child node
@@ -1813,7 +2011,26 @@ static int fw_devlink_create_devlink(struct device *con,
 	    fwnode_is_ancestor_of(sup_handle, con->fwnode))
 		return -EINVAL;
 
-	sup_dev = get_dev_from_fwnode(sup_handle);
+	/*
+	 * SYNC_STATE_ONLY device links don't block probing and supports cycles.
+	 * So cycle detection isn't necessary and shouldn't be done.
+	 */
+	if (!(flags & DL_FLAG_SYNC_STATE_ONLY)) {
+		device_links_write_lock();
+		if (__fw_devlink_relax_cycles(con, sup_handle)) {
+			__fwnode_link_cycle(link);
+			flags = fw_devlink_get_flags(link->flags);
+			dev_info(con, "Fixed dependency cycle(s) with %pfwf\n",
+				 sup_handle);
+		}
+		device_links_write_unlock();
+	}
+
+	if (sup_handle->flags & FWNODE_FLAG_NOT_DEVICE)
+		sup_dev = fwnode_get_next_parent_dev(sup_handle);
+	else
+		sup_dev = get_dev_from_fwnode(sup_handle);
+
 	if (sup_dev) {
 		/*
 		 * If it's one of those drivers that don't actually bind to
@@ -1822,71 +2039,34 @@ static int fw_devlink_create_devlink(struct device *con,
 		 */
 		if (sup_dev->links.status == DL_DEV_NO_DRIVER &&
 		    sup_handle->flags & FWNODE_FLAG_INITIALIZED) {
+			dev_dbg(con,
+				"Not linking %pfwf - dev might never probe\n",
+				sup_handle);
 			ret = -EINVAL;
 			goto out;
 		}
 
-		/*
-		 * If this fails, it is due to cycles in device links.  Just
-		 * give up on this link and treat it as invalid.
-		 */
-		if (!device_link_add(con, sup_dev, flags) &&
-		    !(flags & DL_FLAG_SYNC_STATE_ONLY)) {
-			dev_info(con, "Fixing up cyclic dependency with %s\n",
-				 dev_name(sup_dev));
-			device_links_write_lock();
-			fw_devlink_relax_cycle(con, sup_dev);
-			device_links_write_unlock();
-			device_link_add(con, sup_dev,
-					FW_DEVLINK_FLAGS_PERMISSIVE);
+		if (!device_link_add(con, sup_dev, flags)) {
+			dev_err(con, "Failed to create device link with %s\n",
+				dev_name(sup_dev));
 			ret = -EINVAL;
 		}
 
 		goto out;
 	}
 
-	/* Supplier that's already initialized without a struct device. */
-	if (sup_handle->flags & FWNODE_FLAG_INITIALIZED)
-		return -EINVAL;
-
-	/*
-	 * DL_FLAG_SYNC_STATE_ONLY doesn't block probing and supports
-	 * cycles. So cycle detection isn't necessary and shouldn't be
-	 * done.
-	 */
-	if (flags & DL_FLAG_SYNC_STATE_ONLY)
-		return -EAGAIN;
-
 	/*
-	 * If we can't find the supplier device from its fwnode, it might be
-	 * due to a cyclic dependency between fwnodes. Some of these cycles can
-	 * be broken by applying logic. Check for these types of cycles and
-	 * break them so that devices in the cycle probe properly.
-	 *
-	 * If the supplier's parent is dependent on the consumer, then the
-	 * consumer and supplier have a cyclic dependency. Since fw_devlink
-	 * can't tell which of the inferred dependencies are incorrect, don't
-	 * enforce probe ordering between any of the devices in this cyclic
-	 * dependency. Do this by relaxing all the fw_devlink device links in
-	 * this cycle and by treating the fwnode link between the consumer and
-	 * the supplier as an invalid dependency.
+	 * Supplier or supplier's ancestor already initialized without a struct
+	 * device or being probed by a driver.
 	 */
-	sup_dev = fwnode_get_next_parent_dev(sup_handle);
-	if (sup_dev && device_is_dependent(con, sup_dev)) {
-		dev_info(con, "Fixing up cyclic dependency with %pfwP (%s)\n",
-			 sup_handle, dev_name(sup_dev));
-		device_links_write_lock();
-		fw_devlink_relax_cycle(con, sup_dev);
-		device_links_write_unlock();
-		ret = -EINVAL;
-	} else {
-		/*
-		 * Can't check for cycles or no cycles. So let's try
-		 * again later.
-		 */
-		ret = -EAGAIN;
+	if (fwnode_init_without_drv(sup_handle) ||
+	    fwnode_ancestor_init_without_drv(sup_handle)) {
+		dev_dbg(con, "Not linking %pfwf - might never become dev\n",
+			sup_handle);
+		return -EINVAL;
 	}
 
+	ret = -EAGAIN;
 out:
 	put_device(sup_dev);
 	return ret;
@@ -1914,7 +2094,6 @@ static void __fw_devlink_link_to_consumers(struct device *dev)
 	struct fwnode_link *link, *tmp;
 
 	list_for_each_entry_safe(link, tmp, &fwnode->consumers, s_hook) {
-		u32 dl_flags = fw_devlink_get_flags();
 		struct device *con_dev;
 		bool own_link = true;
 		int ret;
@@ -1944,14 +2123,13 @@ static void __fw_devlink_link_to_consumers(struct device *dev)
 				con_dev = NULL;
 			} else {
 				own_link = false;
-				dl_flags = FW_DEVLINK_FLAGS_PERMISSIVE;
 			}
 		}
 
 		if (!con_dev)
 			continue;
 
-		ret = fw_devlink_create_devlink(con_dev, fwnode, dl_flags);
+		ret = fw_devlink_create_devlink(con_dev, fwnode, link);
 		put_device(con_dev);
 		if (!own_link || ret == -EAGAIN)
 			continue;
@@ -1971,10 +2149,7 @@ static void __fw_devlink_link_to_consumers(struct device *dev)
  *
  * The function creates normal (non-SYNC_STATE_ONLY) device links between @dev
  * and the real suppliers of @dev. Once these device links are created, the
- * fwnode links are deleted. When such device links are successfully created,
- * this function is called recursively on those supplier devices. This is
- * needed to detect and break some invalid cycles in fwnode links.  See
- * fw_devlink_create_devlink() for more details.
+ * fwnode links are deleted.
  *
  * In addition, it also looks at all the suppliers of the entire fwnode tree
  * because some of the child devices of @dev that have not been added yet
@@ -1992,44 +2167,16 @@ static void __fw_devlink_link_to_suppliers(struct device *dev,
 	bool own_link = (dev->fwnode == fwnode);
 	struct fwnode_link *link, *tmp;
 	struct fwnode_handle *child = NULL;
-	u32 dl_flags;
-
-	if (own_link)
-		dl_flags = fw_devlink_get_flags();
-	else
-		dl_flags = FW_DEVLINK_FLAGS_PERMISSIVE;
 
 	list_for_each_entry_safe(link, tmp, &fwnode->suppliers, c_hook) {
 		int ret;
-		struct device *sup_dev;
 		struct fwnode_handle *sup = link->supplier;
 
-		ret = fw_devlink_create_devlink(dev, sup, dl_flags);
+		ret = fw_devlink_create_devlink(dev, sup, link);
 		if (!own_link || ret == -EAGAIN)
 			continue;
 
 		__fwnode_link_del(link);
-
-		/* If no device link was created, nothing more to do. */
-		if (ret)
-			continue;
-
-		/*
-		 * If a device link was successfully created to a supplier, we
-		 * now need to try and link the supplier to all its suppliers.
-		 *
-		 * This is needed to detect and delete false dependencies in
-		 * fwnode links that haven't been converted to a device link
-		 * yet. See comments in fw_devlink_create_devlink() for more
-		 * details on the false dependency.
-		 *
-		 * Without deleting these false dependencies, some devices will
-		 * never probe because they'll keep waiting for their false
-		 * dependency fwnode links to be converted to device links.
-		 */
-		sup_dev = get_dev_from_fwnode(sup);
-		__fw_devlink_link_to_suppliers(sup_dev, sup_dev->fwnode);
-		put_device(sup_dev);
 	}
 
 	/*
@@ -2312,7 +2459,7 @@ static void device_get_ownership(const struct kobject *kobj, kuid_t *uid, kgid_t
 		dev->class->get_ownership(dev, uid, gid);
 }
 
-static struct kobj_type device_ktype = {
+static const struct kobj_type device_ktype = {
 	.release	= device_release,
 	.sysfs_ops	= &dev_sysfs_ops,
 	.namespace	= device_namespace,
@@ -2345,9 +2492,9 @@ static const char *dev_uevent_name(const struct kobject *kobj)
 	return NULL;
 }
 
-static int dev_uevent(struct kobject *kobj, struct kobj_uevent_env *env)
+static int dev_uevent(const struct kobject *kobj, struct kobj_uevent_env *env)
 {
-	struct device *dev = kobj_to_dev(kobj);
+	const struct device *dev = kobj_to_dev(kobj);
 	int retval = 0;
 
 	/* add device node properties if present */
@@ -2950,7 +3097,7 @@ struct kobj_ns_type_operations *class_dir_child_ns_type(const struct kobject *ko
 	return dir->class->ns_type;
 }
 
-static struct kobj_type class_dir_ktype = {
+static const struct kobj_type class_dir_ktype = {
 	.release	= class_dir_release,
 	.sysfs_ops	= &kobj_sysfs_ops,
 	.child_ns_type	= class_dir_child_ns_type
@@ -2984,8 +3131,9 @@ static DEFINE_MUTEX(gdp_mutex);
 static struct kobject *get_device_parent(struct device *dev,
 					 struct device *parent)
 {
+	struct kobject *kobj = NULL;
+
 	if (dev->class) {
-		struct kobject *kobj = NULL;
 		struct kobject *parent_kobj;
 		struct kobject *k;
 
@@ -3033,8 +3181,15 @@ static struct kobject *get_device_parent(struct device *dev,
 	}
 
 	/* subsystems can specify a default root directory for their devices */
-	if (!parent && dev->bus && dev->bus->dev_root)
-		return &dev->bus->dev_root->kobj;
+	if (!parent && dev->bus) {
+		struct device *dev_root = bus_get_dev_root(dev->bus);
+
+		if (dev_root) {
+			kobj = &dev_root->kobj;
+			put_device(dev_root);
+			return kobj;
+		}
+	}
 
 	if (parent)
 		return &parent->kobj;
@@ -3371,7 +3526,7 @@ int device_add(struct device *dev)
 	/* we require the name to be set before, and pass NULL */
 	error = kobject_add(&dev->kobj, dev->kobj.parent, NULL);
 	if (error) {
-		glue_dir = get_glue_dir(dev);
+		glue_dir = kobj;
 		goto Error;
 	}
 
@@ -3411,10 +3566,7 @@ int device_add(struct device *dev)
 	/* Notify clients of device addition.  This call must come
 	 * after dpm_sysfs_add() and before kobject_uevent().
 	 */
-	if (dev->bus)
-		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
-					     BUS_NOTIFY_ADD_DEVICE, dev);
-
+	bus_notify(dev, BUS_NOTIFY_ADD_DEVICE);
 	kobject_uevent(&dev->kobj, KOBJ_ADD);
 
 	/*
@@ -3471,6 +3623,7 @@ done:
 	device_pm_remove(dev);
 	dpm_sysfs_remove(dev);
  DPMError:
+	dev->driver = NULL;
 	bus_remove_device(dev);
  BusError:
 	device_remove_attrs(dev);
@@ -3594,9 +3747,7 @@ void device_del(struct device *dev)
 	 * before dpm_sysfs_remove().
 	 */
 	noio_flag = memalloc_noio_save();
-	if (dev->bus)
-		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
-					     BUS_NOTIFY_DEL_DEVICE, dev);
+	bus_notify(dev, BUS_NOTIFY_DEL_DEVICE);
 
 	dpm_sysfs_remove(dev);
 	if (parent)
@@ -3627,9 +3778,7 @@ void device_del(struct device *dev)
 	device_platform_notify_remove(dev);
 	device_links_purge(dev);
 
-	if (dev->bus)
-		blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
-					     BUS_NOTIFY_REMOVED_DEVICE, dev);
+	bus_notify(dev, BUS_NOTIFY_REMOVED_DEVICE);
 	kobject_uevent(&dev->kobj, KOBJ_REMOVE);
 	glue_dir = get_glue_dir(dev);
 	kobject_del(&dev->kobj);
@@ -3697,7 +3846,7 @@ static struct device *next_device(struct klist_iter *i)
  * a name. This memory is returned in tmp and needs to be
  * freed by the caller.
  */
-const char *device_get_devnode(struct device *dev,
+const char *device_get_devnode(const struct device *dev,
 			       umode_t *mode, kuid_t *uid, kgid_t *gid,
 			       const char **tmp)
 {