device property: add description of fwnode cases

[linux-2.6-microblaze.git] / drivers / base / core.c

diff --git a/drivers/base/core.c b/drivers/base/core.c
index 51b9545..14f1658 100644 (file)
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -4414,6 +4414,12 @@ static inline bool fwnode_is_primary(struct fwnode_handle *fwnode)
  *
  * Set the device's firmware node pointer to @fwnode, but if a secondary
  * firmware node of the device is present, preserve it.
+ *
+ * Valid fwnode cases are:
+ *  - primary --> secondary --> -ENODEV
+ *  - primary --> NULL
+ *  - secondary --> -ENODEV
+ *  - NULL
  */
 void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
 {
@@ -4432,6 +4438,7 @@ void set_primary_fwnode(struct device *dev, struct fwnode_handle *fwnode)
        } else {
                if (fwnode_is_primary(fn)) {
                        dev->fwnode = fn->secondary;
+                       /* Set fn->secondary = NULL, so fn remains the primary fwnode */
                        if (!(parent && fn == parent->fwnode))
                                fn->secondary = NULL;
                } else {