> The st_lsm6dsx_acc_channels array of struct iio_chan_spec has a non-NULL
> event_spec field, indicating support for IIO events. However, event
> detection is not supported for all sensors, and if userspace tries to
> configure accelerometer wakeup events on a sensor device that does not
> support them (e.g. LSM6DS0), st_lsm6dsx_write_event() dereferences a NULL
> pointer when trying to write to the wakeup register.
> Define an additional struct iio_chan_spec array whose members have a NULL
> event_spec field, and use this array instead of st_lsm6dsx_acc_channels for
> sensors without event detection capability.
> 
> Fixes: b5969abfa8b8 ("iio: imu: st_lsm6dsx: add motion events")
> Signed-off-by: Francesco Lavra <flavra@baylibre.com>

Acked-by: Lorenzo Bianconi <lorenzo@kernel.org>

> ---
>  drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c | 15 +++++++++++----
>  1 file changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> index 216160549b5a..a09df9d772dd 100644
> --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
> @@ -103,6 +103,13 @@ static const struct iio_chan_spec st_lsm6dsx_acc_channels[] = {
>  	IIO_CHAN_SOFT_TIMESTAMP(3),
>  };
>  
> +static const struct iio_chan_spec st_lsm6ds0_acc_channels[] = {
> +	ST_LSM6DSX_CHANNEL(IIO_ACCEL, 0x28, IIO_MOD_X, 0),
> +	ST_LSM6DSX_CHANNEL(IIO_ACCEL, 0x2a, IIO_MOD_Y, 1),
> +	ST_LSM6DSX_CHANNEL(IIO_ACCEL, 0x2c, IIO_MOD_Z, 2),
> +	IIO_CHAN_SOFT_TIMESTAMP(3),
> +};
> +
>  static const struct iio_chan_spec st_lsm6dsx_gyro_channels[] = {
>  	ST_LSM6DSX_CHANNEL(IIO_ANGL_VEL, 0x22, IIO_MOD_X, 0),
>  	ST_LSM6DSX_CHANNEL(IIO_ANGL_VEL, 0x24, IIO_MOD_Y, 1),
> @@ -144,8 +151,8 @@ static const struct st_lsm6dsx_settings st_lsm6dsx_sensor_settings[] = {
>  		},
>  		.channels = {
>  			[ST_LSM6DSX_ID_ACC] = {
> -				.chan = st_lsm6dsx_acc_channels,
> -				.len = ARRAY_SIZE(st_lsm6dsx_acc_channels),
> +				.chan = st_lsm6ds0_acc_channels,
> +				.len = ARRAY_SIZE(st_lsm6ds0_acc_channels),
>  			},
>  			[ST_LSM6DSX_ID_GYRO] = {
>  				.chan = st_lsm6ds0_gyro_channels,
> @@ -1445,8 +1452,8 @@ static const struct st_lsm6dsx_settings st_lsm6dsx_sensor_settings[] = {
>  		},
>  		.channels = {
>  			[ST_LSM6DSX_ID_ACC] = {
> -				.chan = st_lsm6dsx_acc_channels,
> -				.len = ARRAY_SIZE(st_lsm6dsx_acc_channels),
> +				.chan = st_lsm6ds0_acc_channels,
> +				.len = ARRAY_SIZE(st_lsm6ds0_acc_channels),
>  			},
>  			[ST_LSM6DSX_ID_GYRO] = {
>  				.chan = st_lsm6dsx_gyro_channels,
> -- 
> 2.39.5
>