[alsa-devel] [PATCH] wm8753: Skip noop reconfiguration of DAI mode

Timo Juhani Lindfors timo.lindfors at iki.fi
Thu Nov 17 01:52:50 CET 2011

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 at fluxnetz.de>.

Signed-off-by: Timo Juhani Lindfors <timo.lindfors at iki.fi>
 sound/soc/codecs/wm8753.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)

diff --git a/sound/soc/codecs/wm8753.c b/sound/soc/codecs/wm8753.c
index a950471..3a629d0 100644
--- a/sound/soc/codecs/wm8753.c
+++ b/sound/soc/codecs/wm8753.c
@@ -190,6 +190,9 @@ 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;

More information about the Alsa-devel mailing list