[PATCH] iio:accel:kxsd9 fix missing mutex unlock

[Jonathan Cameron <jic23@kernel.org>]

From: Frank Zago <frank@zago.net>

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

Signed-off-by: Frank Zago <frank@zago.net>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
---
I have reworked this from a patch sent to me by Frank and put it
into the correct format.

Frank, do you mind me adding your sign off on this. It's shorter
than your patch, but the effect is the same.  This approach of unlocking
before checking a return value is a common kernel idiom.

Jonathan

 drivers/iio/accel/kxsd9.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/iio/accel/kxsd9.c b/drivers/iio/accel/kxsd9.c
index d72118d1189c..12df91986dd2 100644
--- a/drivers/iio/accel/kxsd9.c
+++ b/drivers/iio/accel/kxsd9.c
@@ -112,6 +112,7 @@ 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));
+	mutex_unlock(&st->buf_lock);
 	if (ret)
 		return ret;
 	return (((u16)(st->rx[0])) << 8) | (st->rx[1] & 0xF0);
-- 
1.8.4.2