[PATCH] of: add a function to remove an of_fixup

[Uwe Kleine-König]

This function is needed when a device that already registered a fixup in
the probe routine fails later to probe completely. Without unregistering
the fixup the function might later be called with invalid data.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig at pengutronix.de>
---
 common/oftree.c | 19 +++++++++++++++++++
 include/of.h    |  1 +
 2 files changed, 20 insertions(+)

diff --git a/common/oftree.c b/common/oftree.c
index 50fc95b58820..f75d7b4bfe5d 100644
--- a/common/oftree.c
+++ b/common/oftree.c
@@ -160,6 +160,25 @@ int of_register_fixup(int (*fixup)(struct device_node *, void *), void *context)
 }
 
 /*
+ * Remove a previously registered fixup. Only the first (if any) is removed.
+ * Returns 0 if a match was found (and removed), -ENOENT otherwise.
+ */
+int of_unregister_fixup(int (*fixup)(struct device_node *, void *),
+			void *context)
+{
+	struct of_fixup *of_fixup;
+
+	list_for_each_entry(of_fixup, &of_fixup_list, list) {
+		if (of_fixup->fixup == fixup && of_fixup->context == context) {
+			list_del(&of_fixup->list);
+			return 0;
+		}
+	}
+
+	return -ENOENT;
+}
+
+/*
  * Apply registered fixups for the given fdt. The fdt must have
  * enough free space to apply the fixups.
  */
diff --git a/include/of.h b/include/of.h
index e73cd7a446b7..c02f5f49aba4 100644
--- a/include/of.h
+++ b/include/of.h
@@ -243,6 +243,7 @@ struct device_d *of_find_device_by_node_path(const char *path);
 #define OF_FIND_PATH_FLAGS_BB 1		/* return .bb device if available */
 int of_find_path(struct device_node *node, const char *propname, char **outpath, unsigned flags);
 int of_register_fixup(int (*fixup)(struct device_node *, void *), void *context);
+int of_unregister_fixup(int (*fixup)(struct device_node *, void *), void *context);
 struct device_node *of_find_node_by_alias(struct device_node *root,
 		const char *alias);
 struct device_node *of_find_node_by_path_or_alias(struct device_node *root,
-- 
2.1.4