On Fri, 13 Mar 2020 18:54:41 +0100
Lorenzo Bianconi <lorenzo@xxxxxxxxxx> wrote:
> st_lsm6dsx suffers of a read misalignment on untagged FIFO when
> all 3 supported sensors (accel, gyro and ext device) are running
> at different ODRs (the use-case is reported in the LSM6DSM Application
> Note at pag 100).
> Fix the issue taking into account decimation factor reading the FIFO
> pattern.
>
> Fixes: e485e2a2cfd6 ("iio: imu: st_lsm6dsx: enable sensor-hub support for lsm6dsm")
> Signed-off-by: Lorenzo Bianconi <lorenzo@xxxxxxxxxx>
Queued up. Not totally sure which branch this will through, but may
well be in next merge window because of timing.
Thanks,
Jonathan
> ---
> drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h | 2 ++
> .../iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c | 23 +++++++++++++------
> 2 files changed, 18 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
> index f2113a63721a..e9e756b1e92f 100644
> --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
> +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx.h
> @@ -337,6 +337,7 @@ enum st_lsm6dsx_fifo_mode {
> * @gain: Configured sensor sensitivity.
> * @odr: Output data rate of the sensor [Hz].
> * @watermark: Sensor watermark level.
> + * @decimator: Sensor decimation factor.
> * @sip: Number of samples in a given pattern.
> * @ts_ref: Sensor timestamp reference for hw one.
> * @ext_info: Sensor settings if it is connected to i2c controller
> @@ -350,6 +351,7 @@ struct st_lsm6dsx_sensor {
> u32 odr;
>
> u16 watermark;
> + u8 decimator;
> u8 sip;
> s64 ts_ref;
>
> diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
> index bb899345f2bb..afd00daeefb2 100644
> --- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
> +++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_buffer.c
> @@ -93,6 +93,7 @@ st_lsm6dsx_get_decimator_val(struct st_lsm6dsx_sensor *sensor, u32 max_odr)
> break;
> }
>
> + sensor->decimator = decimator;
> return i == max_size ? 0 : st_lsm6dsx_decimator_table[i].val;
> }
>
> @@ -337,7 +338,7 @@ static inline int st_lsm6dsx_read_block(struct st_lsm6dsx_hw *hw, u8 addr,
> int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw)
> {
> struct st_lsm6dsx_sensor *acc_sensor, *gyro_sensor, *ext_sensor = NULL;
> - int err, acc_sip, gyro_sip, ts_sip, ext_sip, read_len, offset;
> + int err, sip, acc_sip, gyro_sip, ts_sip, ext_sip, read_len, offset;
> u16 fifo_len, pattern_len = hw->sip * ST_LSM6DSX_SAMPLE_SIZE;
> u16 fifo_diff_mask = hw->settings->fifo_ops.fifo_diff.mask;
> u8 gyro_buff[ST_LSM6DSX_IIO_BUFF_SIZE];
> @@ -399,19 +400,20 @@ int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw)
> acc_sip = acc_sensor->sip;
> ts_sip = hw->ts_sip;
> offset = 0;
> + sip = 0;
>
> while (acc_sip > 0 || gyro_sip > 0 || ext_sip > 0) {
> - if (gyro_sip > 0) {
> + if (gyro_sip > 0 && !(sip % gyro_sensor->decimator)) {
> memcpy(gyro_buff, &hw->buff[offset],
> ST_LSM6DSX_SAMPLE_SIZE);
> offset += ST_LSM6DSX_SAMPLE_SIZE;
> }
> - if (acc_sip > 0) {
> + if (acc_sip > 0 && !(sip % acc_sensor->decimator)) {
> memcpy(acc_buff, &hw->buff[offset],
> ST_LSM6DSX_SAMPLE_SIZE);
> offset += ST_LSM6DSX_SAMPLE_SIZE;
> }
> - if (ext_sip > 0) {
> + if (ext_sip > 0 && !(sip % ext_sensor->decimator)) {
> memcpy(ext_buff, &hw->buff[offset],
> ST_LSM6DSX_SAMPLE_SIZE);
> offset += ST_LSM6DSX_SAMPLE_SIZE;
> @@ -441,18 +443,25 @@ int st_lsm6dsx_read_fifo(struct st_lsm6dsx_hw *hw)
> offset += ST_LSM6DSX_SAMPLE_SIZE;
> }
>
> - if (gyro_sip-- > 0)
> + if (gyro_sip > 0 && !(sip % gyro_sensor->decimator)) {
> iio_push_to_buffers_with_timestamp(
> hw->iio_devs[ST_LSM6DSX_ID_GYRO],
> gyro_buff, gyro_sensor->ts_ref + ts);
> - if (acc_sip-- > 0)
> + gyro_sip--;
> + }
> + if (acc_sip > 0 && !(sip % acc_sensor->decimator)) {
> iio_push_to_buffers_with_timestamp(
> hw->iio_devs[ST_LSM6DSX_ID_ACC],
> acc_buff, acc_sensor->ts_ref + ts);
> - if (ext_sip-- > 0)
> + acc_sip--;
> + }
> + if (ext_sip > 0 && !(sip % ext_sensor->decimator)) {
> iio_push_to_buffers_with_timestamp(
> hw->iio_devs[ST_LSM6DSX_ID_EXT0],
> ext_buff, ext_sensor->ts_ref + ts);
> + ext_sip--;
> + }
> + sip++;
> }
> }
>
