Garbage Collection callback (FDS_EVT_GC) was delayed by Bluetooth LE connection

[hrshtkg]

Hi all,

Now I'm analyzing the bug that is the fault of my application's timing control.

On analyzing, I found the difference that  garbage collection callback was delayed whether the device is connected by bluetooth LE  or not.

The difference time is about 20msec to 60msec, so I wondered if it was affected connection interval.

But this callback is executed under softdevice, so I can't find why this matter occurs in truth.

I'can fix this bug by my application, but I'd like to know why it happened.

Please could you let me know the reason.

My conditions are bellow.

* Softdevice : S132

* nRF5 SDK : 12.2.0

* device : nRF52832

Thank you in advance for your help.

[Simonr]

Hi

Garbage collection will end up below BLE in the priority list. It is documented in the functionality section of the FDS library that garbage collection ideally should be run when BLE activity is low, otherwise the operation might time out, as the SoftDevice will take precedence. When garbage collection times out and the FDS_ERR_TIMEOUT is returned by the FDS_EVT_GC event, the system can continue normal operation. Successive calls to fds_gc will then resume garbage collection.

Best regards,

Simon