i.MX8M Nano fails providing secure BLE pairing response

[dhruv_kakadiya]

Hello NXP team,

We have been working with NXP connectivity team to investigate an issue where DUT(as peripheral role) fails to pair/connect over BLE with any external central device(Android and iOS). And team concluded that issue as host/stack issue and not a controller issue as for Secure connection, host needs to handle the flow and pass information from SMP>L2CAP to Radio layer. Attaching logs/screenshots for pass vs fails case to get detailed insights into HCI pcap capture and btmon logs. Also note that, this issue is somehow highly reproducible with NXP provided custom debug firmware while not easily reproducible with NXP provided production firmware. So when we change this independent Bluetooth firmware, we don't change any other software/hardware components. Also issue is not recoverable with complete device reboot/power-cycle and only recovery steps that we have found is by reloading firmware on the Bluetooth module manually which then warrants to repair already paired central devices in the past.

DUT(Device Under Test) looks like below:

Host: i.MX8M Nano
Controller: 2x2 MIMO 88W8997 SD-SD AWCM276 Bluetooth/WiFi combo module
Operating System: Yocto(Honister release) based Linux
i.MX BSP version: 5.4.70-2.3.0+g4f2631b022d8
BlueZ stack version: 5.65
How Controller is being interfaced with host: Using independent Bluetooth/WiFi firmware and not combo firmware over SDIO-SDIO interface(50 MHz clock)

Can someone please help with this issue? Thanks in advance!

[dhruv_kakadiya]

Hello @Sanket_Parekh, thanks for looking into this! But updating BlueZ stack to 5.66 doesn't help anything in here but introduces even more critical issues where the DUT stops secure connecting (with already secure paired devices) by indicating "connection terminated due to mic failure (0x3d)" error.

Thanks,

Dhruv

[Sanket_Parekh]

Hello @dhruv_kakadiya,

Please find the engineering team response below.

Some questions about this issue:

1. Does it have the same problem when using combo firmware?

2. Does it have the same problem when using on board 88W8987 module or other modules?

Meantime, I did not see logs/screenshots for pass vs fails cases, so please attached them.

Thanks & Regards,
Sanket Parekh

[dhruv_kakadiya]

Hi @Sanket_Parekh,

I don't know if this is the proper medium to share all details and have back and forth comm. Though, I am working with Ryan, Venkat and Greg on this issue. So it would be great if team internally can collaborate on this issue to get to the speed.

Please note that, for many days, this portal service was completely non-functional.

Answers are inline.

1. Does it have the same problem when using combo firmware?

Ans: We don't use combo firmware at all as it's not our use case. So we don't have data analysis on combo firmware.

2. Does it have the same problem when using on board 88W8987 module or other modules?

Ans: We don't have 88W8987 module on board as it's not our use case. So we don't have data analysis on 88W8987 module.

Not sure, why you're not able to see any files that I attached to the ticket, but everything is there. So sorry probably contact NXP support portal team for that issue as I have no idea, how can I make that available from my end. Or if you'll contact people that I mentioned above, then the team will be able to get to the speed much faster anyway.

Thank you for all help!

Dhruv

[Sanket_Parekh]

Hello @dhruv_kakadiya ,

I hope you are doing well.

->Please make sure to check the same with the latest version of bluez.

Please download the latest version 5.66 from the below link.
http://www.bluez.org/download/

I hope it helps!

Thanks & Regards,
Sanket Parekh