1 files changed, 28 insertions, 35 deletions

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 529af59e25ff..94865c9d8adc 100644
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -552,7 +552,7 @@ void device_link_wait_removal(void)
 }
 EXPORT_SYMBOL_GPL(device_link_wait_removal);
 
-static struct class devlink_class = {
+static const struct class devlink_class = {
 	.name = "devlink",
 	.dev_groups = devlink_groups,
 	.dev_release = devlink_dev_release,
@@ -1971,7 +1971,7 @@ static struct device *fwnode_get_next_parent_dev(const struct fwnode_handle *fwn
 
 /**
  * __fw_devlink_relax_cycles - Relax and mark dependency cycles.
- * @con: Potential consumer device.
+ * @con_handle: Potential consumer device fwnode.
  * @sup_handle: Potential supplier's fwnode.
  *
  * Needs to be called with fwnode_lock and device link lock held.
@@ -1989,10 +1989,10 @@ static struct device *fwnode_get_next_parent_dev(const struct fwnode_handle *fwn
  *
  * Return true if one or more cycles were found. Otherwise, return false.
  */
-static bool __fw_devlink_relax_cycles(struct device *con,
+static bool __fw_devlink_relax_cycles(struct fwnode_handle *con_handle,
 				 struct fwnode_handle *sup_handle)
 {
-	struct device *sup_dev = NULL, *par_dev = NULL;
+	struct device *sup_dev = NULL, *par_dev = NULL, *con_dev = NULL;
 	struct fwnode_link *link;
 	struct device_link *dev_link;
 	bool ret = false;
@@ -2009,22 +2009,22 @@ static bool __fw_devlink_relax_cycles(struct device *con,
 
 	sup_handle->flags |= FWNODE_FLAG_VISITED;
 
-	sup_dev = get_dev_from_fwnode(sup_handle);
-
 	/* Termination condition. */
-	if (sup_dev == con) {
+	if (sup_handle == con_handle) {
 		pr_debug("----- cycle: start -----\n");
 		ret = true;
 		goto out;
 	}
 
+	sup_dev = get_dev_from_fwnode(sup_handle);
+	con_dev = get_dev_from_fwnode(con_handle);
 	/*
 	 * 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) {
+	    con_dev && con_dev->links.status == DL_DEV_NO_DRIVER) {
 		ret = false;
 		goto out;
 	}
@@ -2033,7 +2033,7 @@ static bool __fw_devlink_relax_cycles(struct device *con,
 		if (link->flags & FWLINK_FLAG_IGNORE)
 			continue;
 
-		if (__fw_devlink_relax_cycles(con, link->supplier)) {
+		if (__fw_devlink_relax_cycles(con_handle, link->supplier)) {
 			__fwnode_link_cycle(link);
 			ret = true;
 		}
@@ -2048,7 +2048,7 @@ static bool __fw_devlink_relax_cycles(struct device *con,
 	else
 		par_dev = fwnode_get_next_parent_dev(sup_handle);
 
-	if (par_dev && __fw_devlink_relax_cycles(con, par_dev->fwnode)) {
+	if (par_dev && __fw_devlink_relax_cycles(con_handle, par_dev->fwnode)) {
 		pr_debug("%pfwf: cycle: child of %pfwf\n", sup_handle,
 			 par_dev->fwnode);
 		ret = true;
@@ -2066,7 +2066,7 @@ static bool __fw_devlink_relax_cycles(struct device *con,
 		    !(dev_link->flags & DL_FLAG_CYCLE))
 			continue;
 
-		if (__fw_devlink_relax_cycles(con,
+		if (__fw_devlink_relax_cycles(con_handle,
 					      dev_link->supplier->fwnode)) {
 			pr_debug("%pfwf: cycle: depends on %pfwf\n", sup_handle,
 				 dev_link->supplier->fwnode);
@@ -2114,11 +2114,6 @@ static int fw_devlink_create_devlink(struct device *con,
 	if (link->flags & FWLINK_FLAG_IGNORE)
 		return 0;
 
-	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
 	 * C. However, this would defer the probe of C until the probe of P
@@ -2139,25 +2134,23 @@ static int fw_devlink_create_devlink(struct device *con,
 		return -EINVAL;
 
 	/*
-	 * SYNC_STATE_ONLY device links don't block probing and supports cycles.
-	 * So, one might expect that cycle detection isn't necessary for them.
-	 * However, if the device link was marked as SYNC_STATE_ONLY because
-	 * it's part of a cycle, then we still need to do cycle detection. This
-	 * is because the consumer and supplier might be part of multiple cycles
-	 * and we need to detect all those cycles.
+	 * Don't try to optimize by not calling the cycle detection logic under
+	 * certain conditions. There's always some corner case that won't get
+	 * detected.
 	 */
-	if (!device_link_flag_is_sync_state_only(flags) ||
-	    flags & DL_FLAG_CYCLE) {
-		device_links_write_lock();
-		if (__fw_devlink_relax_cycles(con, sup_handle)) {
-			__fwnode_link_cycle(link);
-			flags = fw_devlink_get_flags(link->flags);
-			pr_debug("----- cycle: end -----\n");
-			dev_info(con, "Fixed dependency cycle(s) with %pfwf\n",
-				 sup_handle);
-		}
-		device_links_write_unlock();
+	device_links_write_lock();
+	if (__fw_devlink_relax_cycles(link->consumer, sup_handle)) {
+		__fwnode_link_cycle(link);
+		pr_debug("----- cycle: end -----\n");
+		pr_info("%pfwf: Fixed dependency cycle(s) with %pfwf\n",
+			link->consumer, sup_handle);
 	}
+	device_links_write_unlock();
+
+	if (con->fwnode == link->consumer)
+		flags = fw_devlink_get_flags(link->flags);
+	else
+		flags = FW_DEVLINK_FLAGS_PERMISSIVE;
 
 	if (sup_handle->flags & FWNODE_FLAG_NOT_DEVICE)
 		sup_dev = fwnode_get_next_parent_dev(sup_handle);
@@ -2180,8 +2173,8 @@ static int fw_devlink_create_devlink(struct device *con,
 		}
 
 		if (con != sup_dev && !device_link_add(con, sup_dev, flags)) {
-			dev_err(con, "Failed to create device link (0x%x) with %s\n",
-				flags, dev_name(sup_dev));
+			dev_err(con, "Failed to create device link (0x%x) with supplier %s for %pfwf\n",
+				flags, dev_name(sup_dev), link->consumer);
 			ret = -EINVAL;
 		}