iio:accel:kxsd9 fix missing mutex unlock

This will leave a lock held after reading from the device, preventing
any further reads.

Signed-off-by: Frank Zago <frank@zago.net>
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

1 files changed, 4 insertions, 3 deletions

diff --git a/drivers/iio/accel/kxsd9.c b/drivers/iio/accel/kxsd9.c
index d72118d1189c..98ba761cbb9c 100644
--- a/drivers/iio/accel/kxsd9.c
+++ b/drivers/iio/accel/kxsd9.c
@@ -112,9 +112,10 @@ static int kxsd9_read(struct iio_dev *indio_dev, u8 address)
         mutex_lock(&st->buf_lock);
         st->tx[0] = KXSD9_READ(address);
         ret = spi_sync_transfer(st->us, xfers, ARRAY_SIZE(xfers));
-        if (ret)
-                return ret;
-        return (((u16)(st->rx[0])) << 8) | (st->rx[1] & 0xF0);
+        if (!ret)
+                ret = (((u16)(st->rx[0])) << 8) | (st->rx[1] & 0xF0);
+        mutex_unlock(&st->buf_lock);
+        return ret;
 }
 
 static IIO_CONST_ATTR(accel_scale_available,