From: Jonathan Cameron <jic23@kernel.org>
To: Martin Kelly <martin@martingkelly.com>
Cc: linux-iio@vger.kernel.org, Hartmut Knaack <knaack.h@gmx.de>,
Lars-Peter Clausen <lars@metafoo.de>,
Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
Rob Herring <robh+dt@kernel.org>,
Daniel Baluta <daniel.baluta@gmail.com>,
devicetree@vger.kernel.org
Subject: Re: [PATCH v4 5/6] iio:bmi160: use iio_pollfunc_store_time
Date: Sat, 9 Feb 2019 15:24:16 +0000 [thread overview]
Message-ID: <20190209152416.535cb74b@archlinux> (raw)
In-Reply-To: <20190202215601.20275-6-martin@martingkelly.com>
On Sat, 2 Feb 2019 13:56:00 -0800
Martin Kelly <martin@martingkelly.com> wrote:
> From: Martin Kelly <martin@martingkelly.com>
>
> 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@martingkelly.com>
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;
next prev parent reply other threads:[~2019-02-09 15:24 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-02-02 21:55 [PATCH v4 0/6] iio:bmi160: add drdy interrupt support Martin Kelly
2019-02-02 21:55 ` [PATCH v4 1/6] iio:bmi160: add SPDX identifiers Martin Kelly
2019-02-09 14:49 ` Jonathan Cameron
2019-02-02 21:55 ` [PATCH v4 2/6] iio:bmi160: add drdy interrupt support Martin Kelly
2019-02-09 15:15 ` Jonathan Cameron
2019-02-02 21:55 ` [PATCH v4 3/6] dt-bindings: fix incorrect bmi160 IRQ note Martin Kelly
2019-02-09 15:17 ` Jonathan Cameron
2019-02-09 18:37 ` Martin Kelly
2019-02-02 21:55 ` [PATCH v4 4/6] dt-bindings: document open-drain property Martin Kelly
2019-02-09 15:20 ` Jonathan Cameron
2019-02-02 21:56 ` [PATCH v4 5/6] iio:bmi160: use iio_pollfunc_store_time Martin Kelly
2019-02-09 15:24 ` Jonathan Cameron [this message]
2019-02-02 21:56 ` [PATCH v4 6/6] iio:bmi160: use if (ret) instead of if (ret < 0) Martin Kelly
2019-02-02 23:12 ` Fabio Estevam
2019-02-03 0:30 ` Martin Kelly
2019-02-04 15:15 ` Fabio Estevam
2019-02-04 17:07 ` Martin Kelly
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