On Sat, 2 Feb 2019 13:56:00 -0800 Martin Kelly <martin@xxxxxxxxxxxxxxxx> wrote: > From: Martin Kelly <martin@xxxxxxxxxxxxxxxx> > > Currently, we snap the timestamp after reading from the buffer and > processing the event. When the IIO poll function is triggered by an > interrupt, 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. > > Do this by using iio_pollfunc_store_time as other drivers do. > > Signed-off-by: Martin Kelly <martin@xxxxxxxxxxxxxxxx> There is one small quirk here I'd forgotten about, but seems unlikely to cause too many problems. There are triggers that only call iio_trigger_poll_chained (which is badly named) and as a result only end up calling the thread part. That would result in no timestamp. It's a hole we really ought to figure out a reliable fix for that effects lots of drivers. Anyhow, I doubt anyone is using this device with that set of triggers so should be fine whilst we think about a more general solution. Applied to the togreg branch of iio.git and pushed out as testing for the autobuilders to play with it. Thanks, Jonathan > --- > drivers/iio/imu/bmi160/bmi160_core.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/iio/imu/bmi160/bmi160_core.c b/drivers/iio/imu/bmi160/bmi160_core.c > index 007f7c532ac4..f3c5b86a281e 100644 > --- a/drivers/iio/imu/bmi160/bmi160_core.c > +++ b/drivers/iio/imu/bmi160/bmi160_core.c > @@ -425,8 +425,7 @@ 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, pf->timestamp); > done: > iio_trigger_notify_done(indio_dev->trig); > return IRQ_HANDLED; > @@ -834,7 +833,8 @@ int bmi160_core_probe(struct device *dev, struct regmap *regmap, > indio_dev->modes = INDIO_DIRECT_MODE; > indio_dev->info = &bmi160_info; > > - ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL, > + ret = devm_iio_triggered_buffer_setup(dev, indio_dev, > + iio_pollfunc_store_time, > bmi160_trigger_handler, NULL); > if (ret < 0) > return ret;
