Signed-off-by: Nicolae Rosia <nicolae.rosia@gmail.com>

Signed-off-by: Nicolae Rosia <nicolae.rosia@gmail.com>

Signed-off-by: Nicolae Rosia <nicolae.rosia@gmail.com>

Land detector: Choose a default alt limit parameter value that ensures regular users are not running into it

Also remove else if branch that cannot be accessed.

This ensures that a mode change will occur immediately when the EKF reports the solution as invalid.

This will help to understand the sensor selection on FMUv5 in different airframes. We do have the RAM and CPU to do this on this platform.

* mc_pos_control: ignore a NaN/inf position setpoint

This is a hotfix that prevents the position controller from trying to
do velocity control with a position setpoint that isn't valid in the
first place.

This is only a workaround, ideally the controls later should not scale
down throttle to the minimum just because the position setpoint is far
away if they still have valid setpoint in z.

* mc_pos_control: use PX4_ISFINITE and not isfinite

The free memory was accessed from interrupt context where it should not be accessed from. We build the statistic now at a fixed rate while not armed.

and avoid doing a loop iteration when the thread is requested to exit
(as it could access _buffer).