Crash due to softdevice assert (id:0x1 pc:0x3FDA info:0x0)

[Eddie]

Hi. We are using the nRF52 sdk v15.2 with S132 v6.1.0 on a nRF52832. Sometimes, when connecting, we get a crash with

identifier 0x1

program counter 0x3FDA

fault information 0x0

In the log when a connection succeeds, we see:

00> [00:14:03.335,221] <debug> nrf_ble_gatt: Peer on connection 0x0 requested a data length of 27 bytes.
00> [00:14:03.335,237] <debug> nrf_ble_gatt: Updating data length to 27 on connection 0x0.
00> [00:14:03.395,204] <debug> nrf_ble_gatt: Data length updated to 27 on connection 0x0.
00> [00:14:03.395,220] <debug> nrf_ble_gatt: max_rx_octets: 27
00> [00:14:03.395,235] <debug> nrf_ble_gatt: max_tx_octets: 27
00> [00:14:03.395,250] <debug> nrf_ble_gatt: max_rx_time: 328
00> [00:14:03.395,265] <debug> nrf_ble_gatt: max_tx_time: 2120

When it fails, we see this:

As you can probably see, our device supports 2 connections at the same time. I suspect it fails when 2 connections are being set up at the same time. Or a connection is setup while a disconnect happens? Any idea what is causing this and how we can avoid it?

[Susheel Nuguru]

My colleague who worked with you with the previous issue is on summer holidays and will be back on Monday. I need to understand more on the indepth technical behavior of this bug from him. We need to wait until he is back.  There are not much details that are recorded that i can see to get more indepth insights on this. Sorry to make you wait and Thank you for understanding.

[Susheel Nuguru]

Hi,

Eddie said:

why we only have to wait to start advertising after a connection. Why isn't this needed on a disconnect (and switch from non-connectable to connectable)?

 it seems that there could be a race condition in the GAP module where it might get to a point in time where it thinks it is running a non connectible advertising while getting a connection.  if you wait few 10's ms before you start the non connectable advertising, it should work as the GAP should be in a settled state by then.