Re: [PATCH] iio: imu: st_lsm6dsx: wait for settling time in st_lsm6dsx_read_oneshot

[Mario TESI <mario.tesi@st.com>]

Tested-by: Mario Tesi <mario.tesi@st.com>
________________________________________
Da: Lorenzo Bianconi <lorenzo@kernel.org>
Inviato: lunedì 31 gennaio 2022 12:08
A: jic23@kernel.org
Cc: lorenzo.bianconi@redhat.com; linux-iio@vger.kernel.org; Mario TESI
Oggetto: [PATCH] iio: imu: st_lsm6dsx: wait for settling time in st_lsm6dsx_read_oneshot

We need to wait for sensor settling time (~ 3/ODR) before reading data
in st_lsm6dsx_read_oneshot routine in order to avoid corrupted samples.

Reported-by: Mario Tesi <mario.tesi@st.com>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
---
 drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
index 727b4b6ac696..93f0c6bce502 100644
--- a/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
+++ b/drivers/iio/imu/st_lsm6dsx/st_lsm6dsx_core.c
@@ -1374,8 +1374,12 @@ static int st_lsm6dsx_read_oneshot(struct st_lsm6dsx_sensor *sensor,
        if (err < 0)
                return err;

+       /*
+        * we need to wait for sensor settling time before
+        * reading data in order to avoid corrupted samples
+        */
        delay = 1000000000 / sensor->odr;
-       usleep_range(delay, 2 * delay);
+       usleep_range(3 * delay, 4 * delay);

        err = st_lsm6dsx_read_locked(hw, addr, &data, sizeof(data));
        if (err < 0)
--
2.34.1