[PATCH 3.16.y-ckt 033/254] staging:iio:ade7758: Fix check if channels are enabled in prenable

[Luis Henriques]

3.16.7-ckt2 -stable review patch.  If anyone has any objections, please let me know.

------------------

From: Lars-Peter Clausen <lars at metafoo.de>

commit 79fa64eb2ee8ccb4bcad7f54caa2699730b10b22 upstream.

We should check if a channel is enabled, not if no channels are enabled.

Fixes: 550268ca1111 ("staging:iio: scrap scan_count and ensure all drivers use active_scan_mask")
Signed-off-by: Lars-Peter Clausen <lars at metafoo.de>
Signed-off-by: Jonathan Cameron <jic23 at kernel.org>
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 drivers/staging/iio/meter/ade7758_ring.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/iio/meter/ade7758_ring.c b/drivers/staging/iio/meter/ade7758_ring.c
index 628e902dd815..6e9006490742 100644
--- a/drivers/staging/iio/meter/ade7758_ring.c
+++ b/drivers/staging/iio/meter/ade7758_ring.c
@@ -87,7 +87,7 @@ static int ade7758_ring_preenable(struct iio_dev *indio_dev)
 {
 	unsigned channel;
 
-	if (!bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength))
+	if (bitmap_empty(indio_dev->active_scan_mask, indio_dev->masklength))
 		return -EINVAL;
 
 	channel = find_first_bit(indio_dev->active_scan_mask,
-- 
2.1.0