iio: gyro: bmg160: wait full startup time after mode change at probe

bmg160_chip_init() calls bmg160_set_mode(BMG160_MODE_NORMAL) and
then waits only 500-1000 us. Per the BMG160 datasheet
(BST-BMG160-DS000-07 Rev. 1.0, May 2013), the start-up and wake-up
times (tsu, twusm) are 30 ms.

The same file already waits BMG160_MAX_STARTUP_TIME_MS (80 ms)
in bmg160_runtime_resume() after the same set_mode(NORMAL)
operation. The 500 us value at probe was likely a unit mix-up;
the old comment said "500 ms" while the code used microseconds.

Reuse the same constant via msleep() and add a code comment
explaining the datasheet basis for the wait. Without this,
register writes that follow the mode change can hit the chip
before it is ready.

Fixes: 22b46c45fb9b ("iio:gyro:bmg160 Gyro Sensor driver")
Signed-off-by: Stepan Ionichev <sozdayvek@gmail.com>
Cc: <Stable@vger.kernel.org>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>

0 files changed, 0 insertions, 0 deletions