[PATCH 4.9 51/88] iio: hid-sensor-trigger: Change get poll value function order to avoid sensor properties losing after resume from S3

[Greg Kroah-Hartman]

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

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

From: Song Hongyan <hongyan.song@xxxxxxxxx>

commit 3bec247474469f769af41e8c80d3a100dd97dd76 upstream.

In function _hid_sensor_power_state(), when hid_sensor_read_poll_value()
is called, sensor's all properties will be updated by the value from
sensor hardware/firmware.
In some implementation, sensor hardware/firmware will do a power cycle
during S3. In this case, after resume, once hid_sensor_read_poll_value()
is called, sensor's all properties which are kept by driver during S3
will be changed to default value.
But instead, if a set feature function is called first, sensor
hardware/firmware will be recovered to the last status. So change the
sensor_hub_set_feature() calling order to behind of set feature function
to avoid sensor properties lose.

Signed-off-by: Song Hongyan <hongyan.song@xxxxxxxxx>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@xxxxxxxxxxxxxxx>
Signed-off-by: Jonathan Cameron <jic23@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 drivers/iio/common/hid-sensors/hid-sensor-trigger.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

--- a/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
+++ b/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
@@ -51,8 +51,6 @@ static int _hid_sensor_power_state(struc
 			st->report_state.report_id,
 			st->report_state.index,
 			HID_USAGE_SENSOR_PROP_REPORTING_STATE_ALL_EVENTS_ENUM);
-
-		poll_value = hid_sensor_read_poll_value(st);
 	} else {
 		int val;
 
@@ -89,7 +87,9 @@ static int _hid_sensor_power_state(struc
 	sensor_hub_get_feature(st->hsdev, st->power_state.report_id,
 			       st->power_state.index,
 			       sizeof(state_val), &state_val);
-	if (state && poll_value)
+	if (state)
+		poll_value = hid_sensor_read_poll_value(st);
+	if (poll_value > 0)
 		msleep_interruptible(poll_value * 2);
 
 	return 0;