ASoC: wm8994: Prevent double lock of accdet_lock mutex on wm1811

wm1811_micd_stop takes the accdet_lock mutex, and is called from two
places, one of which is already holding the accdet_lock. This obviously
causes a lock up.

This patch fixes this issue by removing the lock from wm1811_micd_stop
and ensuring that it is always locked externally.
Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org

sound/soc/codecs/wm8994.c

@@ -3505,6 +3505,7 @@ static irqreturn_t wm8994_mic_irq(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
+/* Should be called with accdet_lock held */
 static void wm1811_micd_stop(struct snd_soc_codec *codec)
 {
 	struct wm8994_priv *wm8994 = snd_soc_codec_get_drvdata(codec);
@@ -3512,14 +3513,10 @@ static void wm1811_micd_stop(struct snd_soc_codec *codec)
 	if (!wm8994->jackdet)
 		return;
 
-	mutex_lock(&wm8994->accdet_lock);
-
 	snd_soc_update_bits(codec, WM8958_MIC_DETECT_1, WM8958_MICD_ENA, 0);
 
 	wm1811_jackdet_set_mode(codec, WM1811_JACKDET_MODE_JACK);
 
-	mutex_unlock(&wm8994->accdet_lock);
-
 	if (wm8994->wm8994->pdata.jd_ext_cap)
 		snd_soc_dapm_disable_pin(&codec->dapm,
 					 "MICBIAS2");
@@ -3560,10 +3557,10 @@ static void wm8958_open_circuit_work(struct work_struct *work)
 						  open_circuit_work.work);
 	struct device *dev = wm8994->wm8994->dev;
 
-	wm1811_micd_stop(wm8994->hubs.codec);
-
 	mutex_lock(&wm8994->accdet_lock);
 
+	wm1811_micd_stop(wm8994->hubs.codec);
+
 	dev_dbg(dev, "Reporting open circuit\n");
 
 	wm8994->jack_mic = false;