Merge tag 'dt-fixes-for-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux

Pull devicetree fixes from Rob Herring:
 "Fix booting on PPC boards.  Changes to of_match_node matching caused
  the serial port on some PPC boards to stop working.  Reverted the
  change and reimplement to split matching between new style compatible
  only matching and fallback to old matching algorithm"

* tag 'dt-fixes-for-3.14' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  of: search the best compatible match first in __of_match_node()
  Revert "OF: base: match each node compatible against all given matches first"

1 files changed, 54 insertions, 34 deletions

diff --git a/drivers/of/base.c b/drivers/of/base.c
index ff85450d5683..10b51106c854 100644
--- a/drivers/of/base.c
+++ b/drivers/of/base.c
@@ -730,46 +730,64 @@ out:
 }
 EXPORT_SYMBOL(of_find_node_with_property);
 
-static
-const struct of_device_id *__of_match_node(const struct of_device_id *matches,
-					   const struct device_node *node)
+static const struct of_device_id *
+of_match_compatible(const struct of_device_id *matches,
+			const struct device_node *node)
 {
 	const char *cp;
 	int cplen, l;
-
-	if (!matches)
-		return NULL;
+	const struct of_device_id *m;
 
 	cp = __of_get_property(node, "compatible", &cplen);
-	do {
-		const struct of_device_id *m = matches;
-
-		/* Check against matches with current compatible string */
+	while (cp && (cplen > 0)) {
+		m = matches;
 		while (m->name[0] || m->type[0] || m->compatible[0]) {
-			int match = 1;
-			if (m->name[0])
-				match &= node->name
-					&& !strcmp(m->name, node->name);
-			if (m->type[0])
-				match &= node->type
-					&& !strcmp(m->type, node->type);
-			if (m->compatible[0])
-				match &= cp
-					&& !of_compat_cmp(m->compatible, cp,
-							strlen(m->compatible));
-			if (match)
+			/* Only match for the entries without type and name */
+			if (m->name[0] || m->type[0] ||
+				of_compat_cmp(m->compatible, cp,
+					 strlen(m->compatible)))
+				m++;
+			else
 				return m;
-			m++;
 		}
 
-		/* Get node's next compatible string */ 
-		if (cp) {
-			l = strlen(cp) + 1;
-			cp += l;
-			cplen -= l;
-		}
-	} while (cp && (cplen > 0));
+		/* Get node's next compatible string */
+		l = strlen(cp) + 1;
+		cp += l;
+		cplen -= l;
+	}
+
+	return NULL;
+}
+
+static
+const struct of_device_id *__of_match_node(const struct of_device_id *matches,
+					   const struct device_node *node)
+{
+	const struct of_device_id *m;
 
+	if (!matches)
+		return NULL;
+
+	m = of_match_compatible(matches, node);
+	if (m)
+		return m;
+
+	while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
+		int match = 1;
+		if (matches->name[0])
+			match &= node->name
+				&& !strcmp(matches->name, node->name);
+		if (matches->type[0])
+			match &= node->type
+				&& !strcmp(matches->type, node->type);
+		if (matches->compatible[0])
+			match &= __of_device_is_compatible(node,
+							   matches->compatible);
+		if (match)
+			return matches;
+		matches++;
+	}
 	return NULL;
 }
 
@@ -778,10 +796,12 @@ const struct of_device_id *__of_match_node(const struct of_device_id *matches,
  *	@matches:	array of of device match structures to search in
  *	@node:		the of device structure to match against
  *
- *	Low level utility function used by device matching. Matching order
- *	is to compare each of the node's compatibles with all given matches
- *	first. This implies node's compatible is sorted from specific to
- *	generic while matches can be in any order.
+ *	Low level utility function used by device matching. We have two ways
+ *	of matching:
+ *	- Try to find the best compatible match by comparing each compatible
+ *	  string of device node with all the given matches respectively.
+ *	- If the above method failed, then try to match the compatible by using
+ *	  __of_device_is_compatible() besides the match in type and name.
  */
 const struct of_device_id *of_match_node(const struct of_device_id *matches,
 					 const struct device_node *node)