On Mon, Nov 19, 2018 at 2:54 AM Martin Kelly <martin@xxxxxxxxxxxxxxxx> wrote:
>
> From: Martin Kelly <martin@xxxxxxxxxxxxxxxx>
>
> Currently, we snap the timestamp after reading from the buffer and
> processing the event. Technically, we can get a slightly more accurate
> timestamp by snapping it prior to reading the data, since the data was
> already generated prior to entering the trigger handler. This is not going
> to make a huge difference, but we might as well improve slightly.
>
> Signed-off-by: Martin Kelly <martin@xxxxxxxxxxxxxxxx>
Makes sense to me.
Acked-by: Daniel Baluta <daniel.baluta@xxxxxxxxx>
Would be nice to see some datapoints and compare the differences.
> ---
> drivers/iio/imu/bmi160/bmi160_core.c | 4 ++--
> 1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/iio/imu/bmi160/bmi160_core.c b/drivers/iio/imu/bmi160/bmi160_core.c
> index c85659ca9507..4d9d59d9e3a9 100644
> --- a/drivers/iio/imu/bmi160/bmi160_core.c
> +++ b/drivers/iio/imu/bmi160/bmi160_core.c
> @@ -384,6 +384,7 @@ static irqreturn_t bmi160_trigger_handler(int irq, void *p)
> {
> struct iio_poll_func *pf = p;
> struct iio_dev *indio_dev = pf->indio_dev;
> + s64 ts = iio_get_time_ns(indio_dev);
> struct bmi160_data *data = iio_priv(indio_dev);
> __le16 buf[16];
> /* 3 sens x 3 axis x __le16 + 3 x __le16 pad + 4 x __le16 tstamp */
> @@ -399,8 +400,7 @@ static irqreturn_t bmi160_trigger_handler(int irq, void *p)
> buf[j++] = sample;
> }
>
> - iio_push_to_buffers_with_timestamp(indio_dev, buf,
> - iio_get_time_ns(indio_dev));
> + iio_push_to_buffers_with_timestamp(indio_dev, buf, ts);
> done:
> iio_trigger_notify_done(indio_dev->trig);
> return IRQ_HANDLED;
> --
> 2.11.0
>
