[3.13.y.z extended stable] Patch "ASoC: wm8994: Prevent double lock of accdet_lock mutex on wm1811" has been added to staging queue

[Kamal Mostafa]

This is a note to let you know that I have just added a patch titled

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

to the linux-3.13.y-queue branch of the 3.13.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.13.y-queue

This patch is scheduled to be released in version 3.13.11.7.

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.13.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Kamal

------

>From 0a57c3890080d3b3d7383ff3c7ffcb013646d27c Mon Sep 17 00:00:00 2001
From: Charles Keepax <ckeepax at opensource.wolfsonmicro.com>
Date: Mon, 16 Jun 2014 21:24:03 +0100
Subject: ASoC: wm8994: Prevent double lock of accdet_lock mutex on wm1811

commit b38314179c9ccb789e6fe967cff171fa817e8978 upstream.

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 at opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie at linaro.org>
Signed-off-by: Kamal Mostafa <kamal at canonical.com>
---
 sound/soc/codecs/wm8994.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/sound/soc/codecs/wm8994.c b/sound/soc/codecs/wm8994.c
index 86426a1..c9ce977 100644
--- a/sound/soc/codecs/wm8994.c
+++ b/sound/soc/codecs/wm8994.c
@@ -3492,6 +3492,7 @@ 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);
@@ -3499,14 +3500,10 @@ 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");
@@ -3547,10 +3544,10 @@ 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;
--
1.9.1