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

From: Greg Kroah-Hartman
Date: Tue Mar 28 2017 - 09:06:57 EST


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;