1 files changed, 13 insertions, 8 deletions

diff --git a/sound/soc/codecs/cs4270.c b/sound/soc/codecs/cs4270.c
index 43d50a4d8089..5d601ad6da70 100644
--- a/sound/soc/codecs/cs4270.c
+++ b/sound/soc/codecs/cs4270.c
@@ -294,19 +294,24 @@ static unsigned int cs4270_read_reg_cache(struct snd_soc_codec *codec,
 static int cs4270_i2c_write(struct snd_soc_codec *codec, unsigned int reg,
                             unsigned int value)
 {
+        u8 *cache = codec->reg_cache;
+
         if ((reg < CS4270_FIRSTREG) || (reg > CS4270_LASTREG))
                 return -EIO;
 
-        if (i2c_smbus_write_byte_data(codec->control_data, reg, value) == 0) {
+        /* Only perform an I2C operation if the new value is different */
+        if (cache[reg - CS4270_FIRSTREG] != value) {
+                struct i2c_client *client = codec->control_data;
+                if (i2c_smbus_write_byte_data(client, reg, value)) {
+                        printk(KERN_ERR "cs4270: I2C write failed\n");
+                        return -EIO;
+                }
+
                 /* We've written to the hardware, so update the cache */
-                u8 *cache = codec->reg_cache;
                 cache[reg - CS4270_FIRSTREG] = value;
-                return 0;
-        } else {
-                printk(KERN_ERR "cs4270: I2C write of register %u failed\n",
-                        reg);
-                return -EIO;
         }
+
+        return 0;
 }
 
 /*
@@ -521,7 +526,7 @@ static int cs4270_i2c_detach(struct i2c_client *client)
 /* A list of non-DAPM controls that the CS4270 supports */
 static const struct snd_kcontrol_new cs4270_snd_controls[] = {
         SOC_DOUBLE_R("Master Playback Volume",
-                CS4270_VOLA, CS4270_VOLB, 0, 0xFF, 0)
+                CS4270_VOLA, CS4270_VOLB, 0, 0xFF, 1)
 };
 
 static struct i2c_driver cs4270_i2c_driver = {