[v5,6/6] iio: imu: st_lsm6dsx: prohibit the use of events and buffered reads simultaneously

Commit Message

Sean Nyekjaer Sept. 9, 2019, 9:45 a.m. UTC

When events and buffered reads is enabled simultaneously, and the first
event accours the interrupt pin stays high.

This can be reverted when we find a solution to allow events and
buffered reads simultaneously.

Signed-off-by: Sean Nyekjaer <[e-mail]>
---
Changes since v4:
 * Use fifo configuration mutex to prevent a race in hw->enable_event
   check.

 drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c | 3 +++
 drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c   | 4 ++++
 2 files changed, 7 insertions(+)

Patch

diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
index ef579650fd52..f9f27a42e49a 100644
--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
@@ -603,6 +603,9 @@  int st_lsm6dsx_update_fifo(struct st_lsm6dsx_sensor *sensor, bool enable)
 
 	mutex_lock(&hw->conf_lock);
 
+	if (hw->enable_event)
+		return -EBUSY;
+
 	if (hw->fifo_mode != ST_LSM6DSX_FIFO_BYPASS) {
 		err = st_lsm6dsx_flush_fifo(hw);
 		if (err < 0)
diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
index 00ba14d15c13..b4df15a8558e 100644
--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
@@ -1340,6 +1340,8 @@  static int st_lsm6dsx_write_event_config(struct iio_dev *iio_dev,
 	if (type != IIO_EV_TYPE_THRESH)
 		return -EINVAL;
 
+	mutex_unlock(&hw->conf_lock);
+
 	if (hw->fifo_mode != ST_LSM6DSX_FIFO_BYPASS)
 		return -EBUSY;
 
@@ -1351,6 +1353,8 @@  static int st_lsm6dsx_write_event_config(struct iio_dev *iio_dev,
 	if (err < 0)
 		return err;
 
+	mutex_unlock(&hw->conf_lock);
+
 	err = st_lsm6dsx_sensor_set_enable(sensor, state);
 	if (err < 0)
 		return err;