[PATCH] iio: imu: bmi270: fix zero timestamp in triggered buffer

[PATCH] iio: imu: bmi270: fix zero timestamp in triggered buffer

[Liu Yufei]

When the device's own data ready trigger is used, the trigger is
polled with iio_trigger_poll_nested() from the threaded IRQ handler.
In that path the pollfunc top half, iio_pollfunc_store_time(), is
never run, so pf->timestamp is left at zero and every sample pushed
to the buffer carries a zero timestamp.

Take the timestamp in the trigger handler itself and drop the top
half, so that a valid timestamp is provided for all triggers.

Fixes: a1854d55f54b ("iio: imu: bmi270: add support for data ready interrupt trigger")
Cc: stable@vger.kernel.org
Signed-off-by: Liu Yufei <lyf98405@gmail.com>
---
 drivers/iio/imu/bmi270/bmi270_core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/iio/imu/bmi270/bmi270_core.c b/drivers/iio/imu/bmi270/bmi270_core.c
index fbcf6bb87acc..40ed1ee5ac58 100644
--- a/drivers/iio/imu/bmi270/bmi270_core.c
+++ b/drivers/iio/imu/bmi270/bmi270_core.c
@@ -840,6 +840,7 @@ static irqreturn_t bmi270_trigger_handler(int irq, void *p)
 	struct iio_poll_func *pf = p;
 	struct iio_dev *indio_dev = pf->indio_dev;
 	struct bmi270_data *data = iio_priv(indio_dev);
+	s64 timestamp = iio_get_time_ns(indio_dev);
 	int ret;
 
 	guard(mutex)(&data->mutex);
@@ -852,7 +853,7 @@ static irqreturn_t bmi270_trigger_handler(int irq, void *p)
 		goto done;
 
 	iio_push_to_buffers_with_timestamp(indio_dev, &data->buffer,
-					   pf->timestamp);
+					   timestamp);
 done:
 	iio_trigger_notify_done(indio_dev->trig);
 	return IRQ_HANDLED;
@@ -1630,8 +1631,7 @@ int bmi270_core_probe(struct device *dev, struct regmap *regmap,
 	if (ret)
 		return ret;
 
-	ret = devm_iio_triggered_buffer_setup(dev, indio_dev,
-					      iio_pollfunc_store_time,
+	ret = devm_iio_triggered_buffer_setup(dev, indio_dev, NULL,
 					      bmi270_trigger_handler, NULL);
 	if (ret)
 		return ret;

---
base-commit: 09f742b49cb2728086d78be2b0b35e4d1d71fc85
change-id: 20261028-bmi270-fix-timestamp-48a194b69db1

Best regards,
--  
Liu Yufei <lyf98405@gmail.com>

Re: [PATCH] iio: imu: bmi270: fix zero timestamp in triggered buffer

[Andy Shevchenko]

On Wed, Oct 28, 2026 at 10:59:26AM +0800, Liu Yufei wrote:
> When the device's own data ready trigger is used, the trigger is
> polled with iio_trigger_poll_nested() from the threaded IRQ handler.
> In that path the pollfunc top half, iio_pollfunc_store_time(), is
> never run, so pf->timestamp is left at zero and every sample pushed
> to the buffer carries a zero timestamp.
> 
> Take the timestamp in the trigger handler itself and drop the top
> half, so that a valid timestamp is provided for all triggers.

...

> +	s64 timestamp = iio_get_time_ns(indio_dev);

Do we need this variable? Why not call it directly?

>  	iio_push_to_buffers_with_timestamp(indio_dev, &data->buffer,
> -					   pf->timestamp);
> +					   timestamp);

					   iio_get_time_ns(indio_dev);

-- 
With Best Regards,
Andy Shevchenko