AP_Stats: update flight time on disarm

[tatsuy]

This PR fixes an issue where flight time was not being updated if the power was shut down immediately after flight.
Since the update occurs in 30-second cycles, turning off the power before the update process means the last flight time is not added.

I have modified update function so that the flight time updates upon disarming, in addition to the regular updates every 30 seconds.

I have confirmed that the flight time is updated immediately after disarming in SITL.

[IamPete1]

Why not add the flush to the set_flying call? That is when the flight time will stop counting up so there should be no change in value. The key thing it needs is the flush to save the value to eeprom.

I think you could just add flush() in there, also updating last_flush_ms.

ardupilot/libraries/AP_Stats/AP_Stats.cpp

Lines 134 to 135 in 61b3ad3

	update_flighttime();
	_flying_ms = 0;

It just seems a little odd to trigger the save on arming when the stat is based on flying.

[tatsuy]

@IamPete1 Thank you for your suggestion.

I think you could just add flush() in there, also updating last_flush_ms.
In this case, runtime will no longer be updated because update_runtime() is no longer called during disarm

If we add update_runtime() and flush() in there, also updating last_flush_ms, runtime is updated whenever the drone is not flying. It could lead to frequent updates of the runtime value.

I thought it would be better to update once only when disarming.

[IamPete1]

If we add update_runtime() and flush() in there, also updating last_flush_ms, runtime is updated whenever the drone is not flying. It could lead to frequent updates of the runtime value.

Right, you would have to check _flying_ms

if (_flying_ms) {
    flush();
    last_flush_ms = now;
}

Having broken out the millis fetch from the other branch of the if to populate "now".

[muramura]

This method adds up to less than 30 seconds.

The notification to GCS is in 30-second increments.
The GCS displays the event as 30 seconds short.

I think that by executing flush() in this method, we can update the flash memory and repair the 30 seconds short of the GCS.

void AP_Stats::set_flying(const bool is_flying)
{
if (is_flying) {
if (!_flying_ms) {
_flying_ms = AP_HAL::millis();
}
} else {
update_flighttime();
_flying_ms = 0;
flush(); ★ To GCS
}
}

[peterbarker]

Concur with Peter and Muramura here; move the update of last_flash_ms into the flush method itself, however, rather than setting it after calling flush

[tatsuy]

Thank you for the reviews.
I added the flush to the set_flying call and moved the update of last_flash_ms into the flush method.
Additionally, I've called not only update_flighttime but also update_runtime to maintain consistency.

For the test:
Twice, I repeated the process of letting SITL fly and then immediately terminating SITL after disarming.
This PR:

It works.

In case of no update_runtime():

STAT_FLTTIME >STAT_RUNTIME and it is not consistent.

[peterbarker]

LGTM

[peterbarker]

Merged, thanks!