Supervision timeout does not expire during 120hz data streaming

[chris.c]

Hi,

I am using an two nrf5340 with hci_ipc enabled one acting as central and one as peripheral built on v2.9.0

The issue I am having is that the supervision timeout doesn't expire when I hard reset the peripheral whilst sending data (len 91) via notifications at 120hz .

My current fix is to set CONFIG_BT_ATT_LOG_LEVEL_DBG=y which then doesn't miss a supervision timeout event. This doesn't feel like a good long term solution to fixing whatever timing issue this is. Please could you help me.  

Problem Flow from Central perspective:

1. Scan and connect
2. Characteristic and CCC descriptor discovery
3. Enable Notifications
4. Central MTU Updated TX: 247 RX: 247 bytes
5. PHY updated: TX PHY 2M, RX PHY 2M
6. Connection Params:interval 7.50 ms, latency 1, timeout 100 ms
7. start stream data over notifications at 120hz
8. wait 3 seconds
9. Hit reset on peripheral 
10. Central Hangs indefinitely with no supervision timeout 

[chris.c]

Hi,

I’m currently going through the code and nothing has helped so far but will continue looking. 

sorry for maybe a stupid question but is the network core not entirely separate and it handles the disconnect callbacks? How could I corrupt the memory on the network core when all my arrays are on the application core?

[Einar Thorsrud]

Hi,

Yes, the network core is a separate CPU with it's own RAM (though comunication with the application core happend via a shared RAM buffer). That you do not see the callback on your applicaiton core application does not mean that the issue has to be on the network core, though. And I saw various other issues on the applicaiton core side when I tested your application.

I do not have hard proof that this is caused by a memory corruption issue, it is just that the observed behaviour (various dififcult to explain crashes, different behaviours when building on different machines and with seemingly unrelated changes), point in that direction.

[chris.c]

I've rebuilt it from the example Bluetooth LE Central and Peripheral HRS ''and I'm still able to break the supervision timeout.

what are the exact prj and ipc_radio configs that I need to increase if it wanted to stream data at the full 2Mbps limit? 

[Einar Thorsrud]

Hi,

You can refer to the througput sample configuration files for that. You have the prj.conf for the app, and this prj.conf for ipc_radio.