motion: wake up main task for all changes in EC parameter.

We need to wake up the main task, even if we disable a sensor. It will
force sending the sensors samples in the FIFO and put a timestamp behind
them.
Also, reduce the interrupt period by 10us to be sure we fire interrupt
to the AP even if there are some variation in the timing calculation.

BUG=b:24367625
BRANCH=smaug
TEST=Run ts.SingleSensorTests overnight.

Change-Id: I6d966d52b5cbb72ba5eb936bc2fad6c06c7d8605
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/312986
Reviewed-by: Alec Berg <alecaberg@chromium.org>
(cherry picked from commit 9d7f1674460ce8e1a9c2fab79909cfd3bc856807)
Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/313481

2 files changed, 16 insertions, 11 deletions

diff --git a/common/motion_sense.c b/common/motion_sense.c
index 8a21377abf..cf342a4191 100644
--- a/common/motion_sense.c
+++ b/common/motion_sense.c
@@ -53,6 +53,13 @@ static int accel_disp;
 #endif
 
 /*
+ * Adjustment in us to ec rate when calculating interrupt interval:
+ * To be sure the EC will send an interrupt even if it finishes processing
+ * events slighly ealier than the previous period.
+ */
+#define MOTION_SENSOR_INT_ADJUSTMENT_US 10
+
+/*
  * Mutex to protect sensor values between host command task and
  * motion sense task:
  * When we process CMD_DUMP, we want to be sure the motion sense
@@ -322,7 +329,7 @@ static int motion_sense_ec_rate(struct motion_sensor_t *sensor)
  */
 static int motion_sense_set_motion_intervals(void)
 {
-	int i, sensor_ec_rate, ec_rate = 0, ec_int_rate = 0, wake_up = 0;
+	int i, sensor_ec_rate, ec_rate = 0, ec_int_rate = 0;
 	struct motion_sensor_t *sensor;
 	for (i = 0; i < motion_sensor_count; ++i) {
 		sensor = &motion_sensors[i];
@@ -345,19 +352,15 @@ static int motion_sense_set_motion_intervals(void)
 		    (sensor_ec_rate && sensor_ec_rate < ec_int_rate))
 			ec_int_rate = sensor_ec_rate;
 	}
+	motion_interval = ec_rate;
+
+	motion_int_interval =
+		MAX(0, ec_int_rate - MOTION_SENSOR_INT_ADJUSTMENT_US);
 	/*
 	 * Wake up the motion sense task: we want to sensor task to take
 	 * in account the new period right away.
 	 */
-	if ((motion_interval == 0 ||
-	     (ec_rate > 0 && motion_interval > ec_rate)) ||
-	    (motion_int_interval == 0 ||
-	     (ec_int_rate > 0 && motion_int_interval > ec_int_rate)))
-		wake_up = 1;
-	motion_interval = ec_rate;
-	motion_int_interval = ec_int_rate;
-	if (wake_up)
-		task_wake(TASK_ID_MOTIONSENSE);
+	task_wake(TASK_ID_MOTIONSENSE);
 	return motion_interval;
 }
 
diff --git a/include/motion_sense.h b/include/motion_sense.h
index d0f5df329b..cd830307e3 100644
--- a/include/motion_sense.h
+++ b/include/motion_sense.h
@@ -51,7 +51,9 @@ struct motion_data_t {
 	 * MSB is used to know if we are rounding up.
 	 */
 	unsigned int odr;
-	/* delay between collection by EC, in us.
+
+	/*
+	 * delay between collection by EC, in us.
 	 * For non FIFO sensor, should be near 1e9/odr to
 	 * collect events.
 	 * For sensor with FIFO, can be much longer.