diff --git a/board/ryu/board.c b/board/ryu/board.c
index 073e6cfab0..02e9ed0191 100644
--- a/board/ryu/board.c
+++ b/board/ryu/board.c
@@ -405,7 +405,7 @@ struct motion_sensor_t motion_sensors[] = {
 			/* EC needs sensor for light adaptive brightness */
 			[SENSOR_CONFIG_EC_S0] = {
 				.odr = 1000,
-				.ec_rate = 1000,
+				.ec_rate = 0,
 			},
 			[SENSOR_CONFIG_EC_S3] = {
 				.odr = 1000,
diff --git a/common/motion_sense.c b/common/motion_sense.c
index 6aeb04bc10..2095882a6f 100644
--- a/common/motion_sense.c
+++ b/common/motion_sense.c
@@ -96,7 +96,7 @@ void motion_sense_fifo_add_unit(struct ec_response_motion_sensor_data *data,
 
 	/* For valid sensors, check if AP really needs this data */
 	if (valid_data) {
-		/* Use Hz, conversion to FP will overflow with mHz */
+		/* Use Hz, conversion to FP will overflow with kHz */
 		fp_t ap_odr =
 			fp_div(BASE_ODR(sensor->config[SENSOR_CONFIG_AP].odr),
 			       1000);
@@ -188,7 +188,7 @@ static inline int motion_sensor_time_to_read(const timestamp_t *ts,
 	if (rate == 0)
 		return 0;
 	/*
-	 * converting from mHz to us, need 1e9,
+	 * converting from kHz to us, need 1e9,
 	 * If within 95% of the time, check sensor.
 	 */
 	return time_after(ts->le.lo,
@@ -219,6 +219,7 @@ int motion_sense_set_data_rate(struct motion_sensor_t *sensor)
 {
 	int roundup = 0, ec_odr = 0, odr = 0;
 	enum sensor_config config_id;
+	timestamp_t ts = get_time();
 
 	/* We assume the sensor is initialized */
 
@@ -238,21 +239,27 @@ int motion_sense_set_data_rate(struct motion_sensor_t *sensor)
 		sensor->name, odr, roundup, config_id,
 		BASE_ODR(sensor->config[SENSOR_CONFIG_AP].odr));
 	sensor->oversampling = 0;
+	/*
+	 * Reset last collection: the last collection may be so much in the past
+	 * it may appear to be in the future.
+	 */
+	sensor->last_collection = ts.le.lo;
 	return sensor->drv->set_data_rate(sensor, odr, roundup);
 }
 
-static inline int motion_sense_select_ec_rate(
+static int motion_sense_select_ec_rate(
 		const struct motion_sensor_t *sensor,
 		enum sensor_config config_id)
 {
 #ifdef CONFIG_ACCEL_FORCE_MODE_MASK
-	if (CONFIG_ACCEL_FORCE_MODE_MASK & (1 << (sensor - motion_sensors)))
+	if (CONFIG_ACCEL_FORCE_MODE_MASK & (1 << (sensor - motion_sensors))) {
+		int rate = BASE_ODR(sensor->config[config_id].odr);
 		/* we have to run ec at the sensor frequency rate.*/
-		if (sensor->config[config_id].odr > 0)
-			return 1000000 / sensor->config[config_id].odr;
+		if (rate > 0)
+			return 1000000 / rate;
 		else
 			return 0;
-	else
+	} else
 #endif
 		return sensor->config[config_id].ec_rate;
 }
@@ -275,9 +282,9 @@ static int motion_sense_ec_rate(struct motion_sensor_t *sensor)
 	ec_rate_from_cfg = motion_sense_select_ec_rate(
 			sensor, motion_sense_get_ec_config());
 
-	if ((ec_rate == 0 && ec_rate_from_cfg != 0) ||
-	    (ec_rate_from_cfg != 0 && ec_rate_from_cfg < ec_rate))
-		ec_rate = ec_rate_from_cfg;
+	if (ec_rate_from_cfg != 0)
+		if (ec_rate == 0 || ec_rate_from_cfg < ec_rate)
+			ec_rate = ec_rate_from_cfg;
 	return ec_rate * MSEC;
 }
 
@@ -308,7 +315,8 @@ int motion_sense_set_motion_intervals(void)
 		if (ec_rate == 0 || sensor_ec_rate < ec_rate)
 			ec_rate = sensor_ec_rate;
 
-		sensor_ec_rate = sensor->config[SENSOR_CONFIG_AP].ec_rate;
+		sensor_ec_rate = motion_sense_select_ec_rate(
+				sensor, SENSOR_CONFIG_AP);
 		if (ec_int_rate_ms == 0 ||
 		    (sensor_ec_rate && sensor_ec_rate < ec_int_rate_ms))
 			ec_int_rate_ms = sensor_ec_rate;
@@ -341,9 +349,7 @@ static inline int motion_sense_init(struct motion_sensor_t *sensor)
 	if (ret != EC_SUCCESS) {
 		sensor->state = SENSOR_INIT_ERROR;
 	} else {
-		timestamp_t ts = get_time();
 		sensor->state = SENSOR_INITIALIZED;
-		sensor->last_collection = ts.le.lo;
 		motion_sense_set_data_rate(sensor);
 	}
 	return ret;
@@ -637,7 +643,6 @@ void motion_sense_task(void)
 					continue;
 				}
 
-				ts_begin_task = get_time();
 				ret = motion_sense_process(sensor, &event,
 						&ts_begin_task);
 				if (ret != EC_SUCCESS)
diff --git a/driver/als_si114x.c b/driver/als_si114x.c
index fb927e9367..fb4a19fc6a 100644
--- a/driver/als_si114x.c
+++ b/driver/als_si114x.c
@@ -482,6 +482,7 @@ static int set_interrupt(const struct motion_sensor_t *s,
 static int init(const struct motion_sensor_t *s)
 {
 	int ret, resol;
+	struct si114x_drv_data_t *data = SI114X_GET_DATA(s);
 
 	/* initialize only once: light must be declared first. */
 	if (s->type == MOTIONSENSE_TYPE_LIGHT) {
@@ -493,6 +494,8 @@ static int init(const struct motion_sensor_t *s)
 		ret = si114x_initialize(s);
 		if (ret != EC_SUCCESS)
 			return ret;
+
+		data->state = SI114X_IDLE;
 		resol = 7;
 	} else {
 		resol = 5;