Re: [PATCH 4/5] iio:magn: do not allocate/de-allocate buffer here but link setup_ops to st_sensors_buffer

["Ardelean, Alexandru" <alexandru.Ardelean@analog.com>]

On Wed, 2019-07-31 at 14:52 -0700, Denis Ciocca wrote:
> [External]
> 
> Setup buffer_setup_ops pre/post enable/disable to use
> st_sensor_buffers functions for memory allocation/de-allocation.
> 

Reviewed-by: Alexandru Ardelean <alexandru.ardelean@analog.com>

> Signed-off-by: Denis Ciocca <denis.ciocca@st.com>
> ---
>  drivers/iio/magnetometer/st_magn_buffer.c | 14 +++-----------
>  1 file changed, 3 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/iio/magnetometer/st_magn_buffer.c b/drivers/iio/magnetometer/st_magn_buffer.c
> index 658d627dad8e..592972f6450e 100644
> --- a/drivers/iio/magnetometer/st_magn_buffer.c
> +++ b/drivers/iio/magnetometer/st_magn_buffer.c
> @@ -31,17 +31,11 @@ int st_magn_trig_set_state(struct iio_trigger *trig, bool state)
>  
>  static int st_magn_buffer_postenable(struct iio_dev *indio_dev)
>  {
> -	struct st_sensor_data *mdata = iio_priv(indio_dev);
>  	int err;
>  
> -	mdata->buffer_data = kmalloc(indio_dev->scan_bytes,
> -				     GFP_DMA | GFP_KERNEL);
> -	if (!mdata->buffer_data)
> -		return -ENOMEM;
> -
>  	err = iio_triggered_buffer_postenable(indio_dev);
>  	if (err < 0)
> -		goto st_magn_free_buffer;
> +		return err;
>  
>  	err = st_sensors_set_enable(indio_dev, true);
>  	if (err < 0)
> @@ -51,14 +45,11 @@ static int st_magn_buffer_postenable(struct iio_dev *indio_dev)
>  
>  st_magn_buffer_predisable:
>  	iio_triggered_buffer_predisable(indio_dev);
> -st_magn_free_buffer:
> -	kfree(mdata->buffer_data);
>  	return err;
>  }
>  
>  static int st_magn_buffer_predisable(struct iio_dev *indio_dev)
>  {
> -	struct st_sensor_data *mdata = iio_priv(indio_dev);
>  	int err, err2;
>  
>  	err = st_sensors_set_enable(indio_dev, false);
> @@ -67,13 +58,14 @@ static int st_magn_buffer_predisable(struct iio_dev *indio_dev)
>  	if (!err)
>  		err = err2;
>  
> -	kfree(mdata->buffer_data);
>  	return err;
>  }
>  
>  static const struct iio_buffer_setup_ops st_magn_buffer_setup_ops = {
> +	.preenable = &st_sensors_buffer_preenable,
>  	.postenable = &st_magn_buffer_postenable,
>  	.predisable = &st_magn_buffer_predisable,
> +	.postdisable = &st_sensors_buffer_postdisable,
>  };
>  
>  int st_magn_allocate_ring(struct iio_dev *indio_dev)