[PATCH 1/2] drivers/of: Add of_detach_node_no_notify()

[Haren Myneni <haren@linux.ibm.com>]

of_changeset_apply() interface adds nodes for action
OF_RECONFIG_ATTACH_NODE and calls notifiers for each attached node.
Then the caller uses of_detach_node() to release each node and
also calls the corresponding notifier function. In the case of
failure from the add notifier for any node, of_changeset_apply()
returns failure after adding nodes. The current implementation
does not the provide any interface to the caller to remove nodes
from the DT without calling notifiers. It may end up having nodes
in DT even though ADD is not successful.

This patch introduces of_detach_node_no_notify() interface for the
caller to only remove node if it is not attached.

Signed-off-by: Haren Myneni <haren@linux.ibm.com>
---
 drivers/of/dynamic.c | 16 ++++++++++++++++
 include/linux/of.h   |  1 +
 2 files changed, 17 insertions(+)

diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c
index 744ce0e1eb24..fc6f22371a97 100644
--- a/drivers/of/dynamic.c
+++ b/drivers/of/dynamic.c
@@ -318,6 +318,22 @@ int of_detach_node(struct device_node *np)
 }
 EXPORT_SYMBOL_GPL(of_detach_node);
 
+/**
+ * of_detach_node_no_notify() - "Unplug" a node from the device
+ * and return without running notifiers.
+ * @np:	Pointer to the caller's Device Node
+ */
+int of_detach_node_no_notify(struct device_node *np)
+{
+	mutex_lock(&of_mutex);
+	if (!of_node_check_flag(np, OF_DETACHED))
+		__of_detach_node(np);
+	mutex_unlock(&of_mutex);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(of_detach_node_no_notify);
+
 void __of_prop_free(struct property *prop)
 {
 	kfree(prop->name);
diff --git a/include/linux/of.h b/include/linux/of.h
index b920aac6b975..7a509341e998 100644
--- a/include/linux/of.h
+++ b/include/linux/of.h
@@ -442,6 +442,7 @@ extern int of_update_property(struct device_node *np, struct property *newprop);
 
 extern int of_attach_node(struct device_node *);
 extern int of_detach_node(struct device_node *);
+extern int of_detach_node_no_notify(struct device_node *);
 
 #define of_match_ptr(_ptr)	(_ptr)
 
-- 
2.55.0