[PATCH 3/4] extcon: arizona: Fix race with microphone detection and removal

[Charles Keepax <ckeepax@opensource.wolfsonmicro.com>]

The microphone detection code is run as delayed work to provide
additional debounce, it is possible that the jack could have been
removed by the time we process the microphone detection. Turn this
case into a no op.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
---
 drivers/extcon/extcon-arizona.c |   13 +++++++++++++
 1 files changed, 13 insertions(+), 0 deletions(-)

diff --git a/drivers/extcon/extcon-arizona.c b/drivers/extcon/extcon-arizona.c
index cce24de..0d70bf6 100644
--- a/drivers/extcon/extcon-arizona.c
+++ b/drivers/extcon/extcon-arizona.c
@@ -782,6 +782,19 @@ static void arizona_micd_detect(struct work_struct *work)
 
 	mutex_lock(&info->lock);
 
+	/* If the cable was removed while measuring ignore the result */
+	ret = extcon_get_cable_state_(&info->edev, ARIZONA_CABLE_MECHANICAL);
+	if (ret < 0) {
+		dev_err(arizona->dev, "Failed to check cable state: %d\n",
+				ret);
+		mutex_unlock(&info->lock);
+		return;
+	} else if (!ret) {
+		dev_dbg(arizona->dev, "Ignoring MICDET for removed cable\n");
+		mutex_unlock(&info->lock);
+		return;
+	}
+
 	for (i = 0; i < 10 && !(val & MICD_LVL_0_TO_8); i++) {
 		ret = regmap_read(arizona->regmap, ARIZONA_MIC_DETECT_3, &val);
 		if (ret != 0) {
-- 
1.7.2.5