From 728697bca3ac68a86f43e19349c082362a6edae8 Mon Sep 17 00:00:00 2001
From: Mark Brown <broonie@opensource.wolfsonmicro.com>
Date: Fri, 18 Nov 2011 16:03:50 +0000
Subject: [PATCH] --- yaml --- r: 280550 b: refs/heads/master c:
 d91e8db2c3bbe8ef0e2f3e1a6ff5b31a8d53ef16 h: refs/heads/master v: v3

---
 [refs]                             | 2 +-
 trunk/drivers/base/regmap/regmap.c | 9 +++++----
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/[refs] b/[refs]
index 28f315abddc6..a9e10904471e 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 4c691664583ef6a91f9ed0e08a75fbd30a5ffd5c
+refs/heads/master: d91e8db2c3bbe8ef0e2f3e1a6ff5b31a8d53ef16
diff --git a/trunk/drivers/base/regmap/regmap.c b/trunk/drivers/base/regmap/regmap.c
index e533368e5598..10ecbba32e10 100644
--- a/trunk/drivers/base/regmap/regmap.c
+++ b/trunk/drivers/base/regmap/regmap.c
@@ -583,18 +583,19 @@ int regmap_update_bits(struct regmap *map, unsigned int reg,
 		       unsigned int mask, unsigned int val)
 {
 	int ret;
-	unsigned int tmp;
+	unsigned int tmp, orig;
 
 	mutex_lock(&map->lock);
 
-	ret = _regmap_read(map, reg, &tmp);
+	ret = _regmap_read(map, reg, &orig);
 	if (ret != 0)
 		goto out;
 
-	tmp &= ~mask;
+	tmp = orig & ~mask;
 	tmp |= val & mask;
 
-	ret = _regmap_write(map, reg, tmp);
+	if (tmp != orig)
+		ret = _regmap_write(map, reg, tmp);
 
 out:
 	mutex_unlock(&map->lock);