[PATCH] ASoC: wcd9335: Fix device reference leak in wcd9335_slim_status()

[Ma Ke]

wcd9335_slim_status() obtains the SLIM interface device with
of_slim_get_device(), which uses device_find_child() internally and
returns the device with a reference held.  As the device_find_child()
documentation says: you will need to drop the reference with
put_device() after use. The reference is stored in wcd->slim_ifc_dev
and never dropped, so the SLIM interface device cannot be released.
Fix it by using devm_add_action_or_reset() or put_device() respectively.

Found by code review.

Fixes: 20aedafdf492 ("ASoC: wcd9335: add support to wcd9335 codec")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Ma Ke <make_ruc2021@xxxxxxx>
---
 sound/soc/codecs/wcd9335.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/sound/soc/codecs/wcd9335.c b/sound/soc/codecs/wcd9335.c
index 40de279a9750..9332082092c7 100644
--- a/sound/soc/codecs/wcd9335.c
+++ b/sound/soc/codecs/wcd9335.c
@@ -5096,6 +5096,13 @@ static int wcd9335_slim_probe(struct slim_device *slim)
 	return 0;
 }
 
+static void wcd9335_put_device_action(void *data)
+{
+	struct device *dev = data;
+
+	put_device(dev);
+}
+
 static int wcd9335_slim_status(struct slim_device *sdev,
 			       enum slim_device_status status)
 {
@@ -5120,6 +5127,11 @@ static int wcd9335_slim_status(struct slim_device *sdev,
 		return -EINVAL;
 	}
 
+	ret = devm_add_action_or_reset(dev, wcd9335_put_device_action,
+			&wcd->slim_ifc_dev->dev);
+	if (ret)
+		return ret;
+
 	slim_get_logical_addr(wcd->slim_ifc_dev);
 
 	wcd->regmap = regmap_init_slimbus(sdev, &wcd9335_regmap_config);
-- 
2.43.0