3 files changed, 45 insertions, 37 deletions

diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
index 119acb078af3..2d3d148b4206 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_lid_angle.c
@@ -121,7 +121,7 @@ static const struct platform_device_id cros_ec_lid_angle_ids[] = {
 	{
 		.name = DRV_NAME,
 	},
-	{ /* sentinel */ }
+	{ }
 };
 MODULE_DEVICE_TABLE(platform, cros_ec_lid_angle_ids);
 
diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
index 66153b1850f1..82cef4a12442 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors.c
@@ -311,7 +311,7 @@ static const struct platform_device_id cros_ec_sensors_ids[] = {
 	{
 		.name = "cros-ec-mag",
 	},
-	{ /* sentinel */ }
+	{ }
 };
 MODULE_DEVICE_TABLE(platform, cros_ec_sensors_ids);
 
diff --git a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
index 7751d6f69b12..700ebcd68ff4 100644
--- a/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
+++ b/drivers/iio/common/cros_ec_sensors/cros_ec_sensors_core.c
@@ -34,25 +34,19 @@
 static int cros_ec_get_host_cmd_version_mask(struct cros_ec_device *ec_dev,
 					     u16 cmd_offset, u16 cmd, u32 *mask)
 {
+	DEFINE_RAW_FLEX(struct cros_ec_command, buf, data,
+			MAX(sizeof(struct ec_response_get_cmd_versions),
+			    sizeof(struct ec_params_get_cmd_versions)));
 	int ret;
-	struct {
-		struct cros_ec_command msg;
-		union {
-			struct ec_params_get_cmd_versions params;
-			struct ec_response_get_cmd_versions resp;
-		};
-	} __packed buf = {
-		.msg = {
-			.command = EC_CMD_GET_CMD_VERSIONS + cmd_offset,
-			.insize = sizeof(struct ec_response_get_cmd_versions),
-			.outsize = sizeof(struct ec_params_get_cmd_versions)
-			},
-		.params = {.cmd = cmd}
-	};
-
-	ret = cros_ec_cmd_xfer_status(ec_dev, &buf.msg);
+
+	buf->command = EC_CMD_GET_CMD_VERSIONS + cmd_offset;
+	buf->insize = sizeof(struct ec_response_get_cmd_versions);
+	buf->outsize = sizeof(struct ec_params_get_cmd_versions);
+	((struct ec_params_get_cmd_versions *)buf->data)->cmd = cmd;
+
+	ret = cros_ec_cmd_xfer_status(ec_dev, buf);
 	if (ret >= 0)
-		*mask = buf.resp.version_mask;
+		*mask = ((struct ec_response_get_cmd_versions *)buf->data)->version_mask;
 	return ret;
 }
 
@@ -97,22 +91,6 @@ static void get_default_min_max_freq(enum motionsensor_type type,
 	}
 }
 
-static int cros_ec_sensor_set_ec_rate(struct cros_ec_sensors_core_state *st,
-				      int rate)
-{
-	int ret;
-
-	if (rate > U16_MAX)
-		rate = U16_MAX;
-
-	mutex_lock(&st->cmd_lock);
-	st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
-	st->param.ec_rate.data = rate;
-	ret = cros_ec_motion_send_host_cmd(st, 0);
-	mutex_unlock(&st->cmd_lock);
-	return ret;
-}
-
 static ssize_t cros_ec_sensor_set_report_latency(struct device *dev,
 						 struct device_attribute *attr,
 						 const char *buf, size_t len)
@@ -128,7 +106,25 @@ static ssize_t cros_ec_sensor_set_report_latency(struct device *dev,
 
 	/* EC rate is in ms. */
 	latency = integer * 1000 + fract / 1000;
-	ret = cros_ec_sensor_set_ec_rate(st, latency);
+
+	mutex_lock(&st->cmd_lock);
+	st->param.cmd = MOTIONSENSE_CMD_EC_RATE;
+	st->param.ec_rate.data = min(U16_MAX, latency);
+	ret = cros_ec_motion_send_host_cmd(st, 0);
+	if (ret < 0) {
+		mutex_unlock(&st->cmd_lock);
+		return ret;
+	}
+
+	/*
+	 * Flush samples currently in the FIFO, especially when the new latency
+	 * is shorter than the old one: new timeout value is only considered when
+	 * there is a new sample available. It can take a while for a slow
+	 * sensor.
+	 */
+	st->param.cmd = MOTIONSENSE_CMD_FIFO_FLUSH;
+	ret = cros_ec_motion_send_host_cmd(st, 0);
+	mutex_unlock(&st->cmd_lock);
 	if (ret < 0)
 		return ret;
 
@@ -486,7 +482,7 @@ const struct iio_chan_spec_ext_info cros_ec_sensors_ext_info[] = {
 		.shared = IIO_SHARED_BY_ALL,
 		.read = cros_ec_sensors_id
 	},
-	{ },
+	{ }
 };
 EXPORT_SYMBOL_GPL(cros_ec_sensors_ext_info);
 
@@ -838,6 +834,18 @@ int cros_ec_sensors_core_write(struct cros_ec_sensors_core_state *st,
 		st->param.sensor_odr.roundup = 1;
 
 		ret = cros_ec_motion_send_host_cmd(st, 0);
+		if (ret)
+			break;
+
+		/* Flush the FIFO when a sensor is stopped.
+		 * If the FIFO has just been emptied, pending samples will be
+		 * stuck until new samples are available. It will not happen
+		 * when all the sensors are stopped.
+		 */
+		if (frequency == 0) {
+			st->param.cmd = MOTIONSENSE_CMD_FIFO_FLUSH;
+			ret = cros_ec_motion_send_host_cmd(st, 0);
+		}
 		break;
 	default:
 		ret = -EINVAL;