[PATCH 4.9 12/32] iio: adc: ti-ads1015: dont return invalid value from buffer setup callbacks

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

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

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

From: Akinobu Mita <akinobu.mita@gmail.com>

commit a6fe5e52d5ecfc98530034d6c9db73777cf41ede upstream.

pm_runtime_get_sync() and pm_runtime_put_autosuspend() return 0 on
success, 1 if the device's runtime PM status was already requested status
or error code on failure.  So a positive return value doesn't indicate an
error condition.

However, any non-zero return values from buffer preenable and postdisable
callbacks are recognized as an error and this driver reuses the return
value from pm_runtime_get_sync() and pm_runtime_put_autosuspend() in
these callbacks.  This change fixes the false error detections.

Cc: Daniel Baluta <daniel.baluta@gmail.com>
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/iio/adc/ti-ads1015.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/iio/adc/ti-ads1015.c
+++ b/drivers/iio/adc/ti-ads1015.c
@@ -234,7 +234,7 @@ static int ads1015_set_power_state(struc
 		ret = pm_runtime_put_autosuspend(dev);
 	}
 
-	return ret;
+	return ret < 0 ? ret : 0;
 }
 
 static