ASoC: wm8753: Skip noop reconfiguration of DAI mode

BugLink: http://bugs.launchpad.net/bugs/902312

commit 2391a0e06789a3f1718dee30b282562f7ed28c87 upstream.

This patch makes it possible to set DAI mode to its currently applied
value even if codec is active. This is necessary to allow

aplay -t raw -r 44100 -f S16_LE -c 2 < /dev/urandom &
alsactl store -f backup.state
alsactl restore -f backup.state

to work without returning errors. This patch is based on a patch sent
by Klaus Kurzmann <mok@fluxnetz.de>.

Signed-off-by: Timo Juhani Lindfors <timo.lindfors@iki.fi>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/sound/soc/codecs/wm8753.c b/sound/soc/codecs/wm8753.c
index aa091a0d818..66d18a3e57f 100644
--- a/sound/soc/codecs/wm8753.c
+++ b/sound/soc/codecs/wm8753.c
@@ -189,6 +189,9 @@ static int wm8753_set_dai(struct snd_kcontrol *kcontrol,
         struct wm8753_priv *wm8753 = snd_soc_codec_get_drvdata(codec);
         u16 ioctl;
 
+        if (wm8753->dai_func == ucontrol->value.integer.value[0])
+                return 0;
+
         if (codec->active)
                 return -EBUSY;