diff mbox series

[v6.1,6/6] iio: imu: st_lsm6dsx: prohibit the use of events and buffered reads simultaneously

Message ID 20190909124518.84025-1-sean@geanix.com (mailing list archive)
State New, archived
Headers show
Series None | expand

Commit Message

Sean Nyekjaer Sept. 9, 2019, 12:45 p.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 <sean@geanix.com>
---
Changes since v4:
 * Use fifo configuration mutex to prevent a race in hw->enable_event check.

Changes since v5:
 * Updated do not return without unlocking mutexes
 * Lock mutex before unlock
 * Runtime tested 
 * Make sure we unlock the mutex in case of failure

 drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c |  5 +++++
 drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c   | 18 ++++++++++++++----
 2 files changed, 19 insertions(+), 4 deletions(-)
diff mbox series

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..b87a1872bc60 100644
--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
@@ -603,6 +603,11 @@  int st_lsm6dsx_update_fifo(struct st_lsm6dsx_sensor *sensor, bool enable)
 
 	mutex_lock(&hw->conf_lock);
 
+	if (hw->enable_event) {
+		err = -EBUSY;
+		goto out;
+	}
+
 	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 de6bddd91471..fb658cb69c9d 100644
--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
@@ -1340,21 +1340,31 @@  static int st_lsm6dsx_write_event_config(struct iio_dev *iio_dev,
 	if (type != IIO_EV_TYPE_THRESH)
 		return -EINVAL;
 
+	mutex_lock(&hw->conf_lock);
+
+	if (hw->fifo_mode != ST_LSM6DSX_FIFO_BYPASS) {
+		err = -EBUSY;
+		goto out;
+	}
+
 	/* do not enable events if they are already enabled */
 	if (state && hw->enable_event)
-		return 0;
+		goto out;
 
 	err = st_lsm6dsx_event_setup(hw, state);
 	if (err < 0)
-		return err;
+		goto out;
 
 	err = st_lsm6dsx_sensor_set_enable(sensor, state);
 	if (err < 0)
-		return err;
+		goto out;
 
 	hw->enable_event = state;
 
-	return 0;
+out:
+	mutex_unlock(&hw->conf_lock);
+
+	return err;
 }
 
 int st_lsm6dsx_set_watermark(struct iio_dev *iio_dev, unsigned int val)