snd_soc_update_bits() will only write new register value if the old value is different from the new value. In additional, snd_soc_update_bits() returns 0 for no change. No need to read WM8994_CLOCKING_1 register before calling snd_soc_update_bits().
Signed-off-by: Axel Lin axel.lin@gmail.com --- sound/soc/codecs/wm8994.c | 11 ++++------- 1 files changed, 4 insertions(+), 7 deletions(-)
diff --git a/sound/soc/codecs/wm8994.c b/sound/soc/codecs/wm8994.c index e537267..4225e1f 100644 --- a/sound/soc/codecs/wm8994.c +++ b/sound/soc/codecs/wm8994.c @@ -208,7 +208,7 @@ static int configure_aif_clock(struct snd_soc_codec *codec, int aif) static int configure_clock(struct snd_soc_codec *codec) { struct wm8994_priv *wm8994 = snd_soc_codec_get_drvdata(codec); - int old, new; + int change, new;
/* Bring up the AIF clocks first */ configure_aif_clock(codec, 0); @@ -229,14 +229,11 @@ static int configure_clock(struct snd_soc_codec *codec) else new = 0;
- old = snd_soc_read(codec, WM8994_CLOCKING_1) & WM8994_SYSCLK_SRC; - - /* If there's no change then we're done. */ - if (old == new) + change = snd_soc_update_bits(codec, WM8994_CLOCKING_1, + WM8994_SYSCLK_SRC, new); + if (!change) return 0;
- snd_soc_update_bits(codec, WM8994_CLOCKING_1, WM8994_SYSCLK_SRC, new); - snd_soc_dapm_sync(&codec->dapm);
return 0;