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Diffstat (limited to 'sound/soc/codecs/da7219.c')
-rw-r--r--sound/soc/codecs/da7219.c14
1 files changed, 10 insertions, 4 deletions
diff --git a/sound/soc/codecs/da7219.c b/sound/soc/codecs/da7219.c
index 13009d08b09a..c7493549a9a5 100644
--- a/sound/soc/codecs/da7219.c
+++ b/sound/soc/codecs/da7219.c
@@ -446,7 +446,7 @@ static int da7219_tonegen_freq_put(struct snd_kcontrol *kcontrol,
struct soc_mixer_control *mixer_ctrl =
(struct soc_mixer_control *) kcontrol->private_value;
unsigned int reg = mixer_ctrl->reg;
- __le16 val;
+ __le16 val_new, val_old;
int ret;
/*
@@ -454,13 +454,19 @@ static int da7219_tonegen_freq_put(struct snd_kcontrol *kcontrol,
* Therefore we need to convert to little endian here to align with
* HW registers.
*/
- val = cpu_to_le16(ucontrol->value.integer.value[0]);
+ val_new = cpu_to_le16(ucontrol->value.integer.value[0]);
mutex_lock(&da7219->ctrl_lock);
- ret = regmap_raw_write(da7219->regmap, reg, &val, sizeof(val));
+ ret = regmap_raw_read(da7219->regmap, reg, &val_old, sizeof(val_old));
+ if (ret == 0 && (val_old != val_new))
+ ret = regmap_raw_write(da7219->regmap, reg,
+ &val_new, sizeof(val_new));
mutex_unlock(&da7219->ctrl_lock);
- return ret;
+ if (ret < 0)
+ return ret;
+
+ return val_old != val_new;
}