of: dynamic: Move dead property list check into property add/update functions

The changeset code checks for a property in the deadprops list when
adding/updating a property, but of_add_property() and
of_update_property() do not. As the users of these functions are pretty
simple, they have not hit this scenario or else the property lists
would get corrupted.

With this there are 3 cases of removing a property from either deadprops
or properties lists, so add a helper to find and remove a matching
property.
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/20230801-dt-changeset-fixes-v3-5-5f0410e007dd@kernel.orgSigned-off-by: Rob Herring <robh@kernel.org>

drivers/of/base.c

@@ -1530,6 +1530,20 @@ int of_count_phandle_with_args(const struct device_node *np, const char *list_na
 }
 EXPORT_SYMBOL(of_count_phandle_with_args);
 
+static struct property *__of_remove_property_from_list(struct property **list, struct property *prop)
+{
+	struct property **next;
+
+	for (next = list; *next; next = &(*next)->next) {
+		if (*next == prop) {
+			*next = prop->next;
+			prop->next = NULL;
+			return prop;
+		}
+	}
+	return NULL;
+}
+
 /**
  * __of_add_property - Add a property to a node without lock operations
  * @np:		Caller's Device Node
@@ -1539,6 +1553,8 @@ int __of_add_property(struct device_node *np, struct property *prop)
 {
 	struct property **next;
 
+	__of_remove_property_from_list(&np->deadprops, prop);
+
 	prop->next = NULL;
 	next = &np->properties;
 	while (*next) {
@@ -1583,21 +1599,14 @@ EXPORT_SYMBOL_GPL(of_add_property);
 
 int __of_remove_property(struct device_node *np, struct property *prop)
 {
-	struct property **next;
-
-	for (next = &np->properties; *next; next = &(*next)->next) {
-		if (*next == prop)
-			break;
+	if (__of_remove_property_from_list(&np->properties, prop)) {
+		/* Found the property, add it to deadprops list */
+		prop->next = np->deadprops;
+		np->deadprops = prop;
+		return 0;
 	}
-	if (*next == NULL)
-		return -ENODEV;
-
-	/* found the node */
-	*next = prop->next;
-	prop->next = np->deadprops;
-	np->deadprops = prop;
 
-	return 0;
+	return -ENODEV;
 }
 
 /**
@@ -1641,6 +1650,8 @@ int __of_update_property(struct device_node *np, struct property *newprop,
 {
 	struct property **next, *oldprop;
 
+	__of_remove_property_from_list(&np->deadprops, newprop);
+
 	for (next = &np->properties; *next; next = &(*next)->next) {
 		if (of_prop_cmp((*next)->name, newprop->name) == 0)
 			break;

drivers/of/dynamic.c

@@ -564,7 +564,6 @@ static int __of_changeset_entry_notify(struct of_changeset_entry *ce,
 
 static int __of_changeset_entry_apply(struct of_changeset_entry *ce)
 {
-	struct property **propp;
 	unsigned long flags;
 	int ret = 0;
 
@@ -579,15 +578,6 @@ static int __of_changeset_entry_apply(struct of_changeset_entry *ce)
 		__of_detach_node(ce->np);
 		break;
 	case OF_RECONFIG_ADD_PROPERTY:
-		/* If the property is in deadprops then it must be removed */
-		for (propp = &ce->np->deadprops; *propp; propp = &(*propp)->next) {
-			if (*propp == ce->prop) {
-				*propp = ce->prop->next;
-				ce->prop->next = NULL;
-				break;
-			}
-		}
-
 		ret = __of_add_property(ce->np, ce->prop);
 		break;
 	case OF_RECONFIG_REMOVE_PROPERTY:
@@ -595,15 +585,6 @@ static int __of_changeset_entry_apply(struct of_changeset_entry *ce)
 		break;
 
 	case OF_RECONFIG_UPDATE_PROPERTY:
-		/* If the property is in deadprops then it must be removed */
-		for (propp = &ce->np->deadprops; *propp; propp = &(*propp)->next) {
-			if (*propp == ce->prop) {
-				*propp = ce->prop->next;
-				ce->prop->next = NULL;
-				break;
-			}
-		}
-
 		ret = __of_update_property(ce->np, ce->prop, &ce->old_prop);
 		break;
 	default: