[PATCH v2] iio: admv1013: initialize callback mutex before registering notifier

[Runyu Xiao]

admv1013_probe() registers a clock notifier whose callback takes st->lock
on POST_RATE_CHANGE. Initialize the mutex before
devm_clk_notifier_register() so the callback cannot observe an
uninitialized lock during probe.

Use devm_mutex_init() so the lock lifetime is tied to the device and
cleanup stays paired with the rest of the managed probe resources.

Fixes: da35a7b526d9 ("iio: frequency: admv1013: add support for ADMV1013")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Runyu Xiao <runyu.xiao@xxxxxxxxxx>
---
 drivers/iio/frequency/admv1013.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/iio/frequency/admv1013.c b/drivers/iio/frequency/admv1013.c
index d8e8d541990f..ff599b5c88ef 100644
--- a/drivers/iio/frequency/admv1013.c
+++ b/drivers/iio/frequency/admv1013.c
@@ -594,11 +594,13 @@ static int admv1013_probe(struct spi_device *spi)
 				     "failed to get the LO input clock\n");
 
 	st->nb.notifier_call = admv1013_freq_change;
-	ret = devm_clk_notifier_register(&spi->dev, st->clkin, &st->nb);
+	ret = devm_mutex_init(&spi->dev, &st->lock);
 	if (ret)
 		return ret;
 
-	mutex_init(&st->lock);
+	ret = devm_clk_notifier_register(&spi->dev, st->clkin, &st->nb);
+	if (ret)
+		return ret;
 
 	ret = admv1013_init(st, vcm_uv);
 	if (ret) {
-- 
2.34.1