iio: imu: inv_icm42600: fix odr switch to the same value

commit c9f3a59 upstream.

ODR switch is done in 2 steps when FIFO is on : change the ODR register
value and acknowledge change when reading the FIFO ODR change flag.
When we are switching to the same odr value, we end up waiting for a
FIFO ODR flag that is never happening.

Fix the issue by doing nothing and exiting properly when we are
switching to the same ODR value.

Fixes: ec74ae9 ("iio: imu: inv_icm42600: add accurate timestamping")
Signed-off-by: Jean-Baptiste Maneyrol <jean-baptiste.maneyrol@tdk.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: jmaneyrol-invn

drivers/iio/imu/inv_icm42600/inv_icm42600_accel.c

@@ -651,6 +651,8 @@ static int inv_icm42600_accel_write_odr(struct iio_dev *indio_dev,
 		return -EINVAL;
 
 	conf.odr = inv_icm42600_accel_odr_conv[idx / 2];
+	if (conf.odr == st->conf.accel.odr)
+		return 0;
 
 	pm_runtime_get_sync(dev);
 	mutex_lock(&st->lock);

drivers/iio/imu/inv_icm42600/inv_icm42600_gyro.c

@@ -358,6 +358,8 @@ static int inv_icm42600_gyro_write_odr(struct iio_dev *indio_dev,
 		return -EINVAL;
 
 	conf.odr = inv_icm42600_gyro_odr_conv[idx / 2];
+	if (conf.odr == st->conf.gyro.odr)
+		return 0;
 
 	pm_runtime_get_sync(dev);
 	mutex_lock(&st->lock);