[v5.1,6/6] iio: imu: st_lsm6dsx: prohibit the use of events and buffered reads simultaneously
diff mbox series

Message ID 20190909095618.70801-1-sean@geanix.com
State New
Headers show
Series
  • Untitled series #171725
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Commit Message

Sean Nyekjaer Sept. 9, 2019, 9:56 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 <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

 drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c |  5 +++++
 drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c   | 13 ++++++++++---
 2 files changed, 15 insertions(+), 3 deletions(-)

Comments

Lorenzo Bianconi Sept. 9, 2019, 10:40 a.m. UTC | #1
> 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
> 
>  drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c |  5 +++++
>  drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c   | 13 ++++++++++---
>  2 files changed, 15 insertions(+), 3 deletions(-)
> 
> 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 00ba14d15c13..a13d0c154b82 100644
> --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> @@ -1340,8 +1340,12 @@ static int st_lsm6dsx_write_event_config(struct iio_dev *iio_dev,
>  	if (type != IIO_EV_TYPE_THRESH)
>  		return -EINVAL;
>  
> -	if (hw->fifo_mode != ST_LSM6DSX_FIFO_BYPASS)
> -		return -EBUSY;
> +	mutex_unlock(&hw->conf_lock);

I _really_ do not think you are testing these patches since there are plenty of
errors here:

1- mutex_unlock instead of mutex_lock
2- returning without releasing the lock

Please put more attention next time and test you patches

Lorenzo

> +
> +	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)
> @@ -1357,7 +1361,10 @@ static int st_lsm6dsx_write_event_config(struct iio_dev *iio_dev,
>  
>  	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)
> -- 
> 2.23.0
>
Sean Nyekjaer Sept. 9, 2019, 11:07 a.m. UTC | #2
On 09/09/2019 12.40, Lorenzo Bianconi wrote:
> I_really_  do not think you are testing these patches since there are plenty of
> errors here:
> 
> 1- mutex_unlock instead of mutex_lock

Again, my bad :)

The error show quite quickly:
WARNING: bad unlock balance detected!

> 2- returning without releasing the lock
> 
> Please put more attention next time and test you patches

Will do...
Thanks for the review

/Sean

Patch
diff mbox series

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 00ba14d15c13..a13d0c154b82 100644
--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
@@ -1340,8 +1340,12 @@  static int st_lsm6dsx_write_event_config(struct iio_dev *iio_dev,
 	if (type != IIO_EV_TYPE_THRESH)
 		return -EINVAL;
 
-	if (hw->fifo_mode != ST_LSM6DSX_FIFO_BYPASS)
-		return -EBUSY;
+	mutex_unlock(&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)
@@ -1357,7 +1361,10 @@  static int st_lsm6dsx_write_event_config(struct iio_dev *iio_dev,
 
 	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)