SoftDevice Controller ASSERT: 53, 296

[Maos]

Hi!

Can you please help me identify what is causing this issue and/or provide more info about this:

[00:04:23.038,330] \033[1;31m<err> bt_sdc_hci_driver: SoftDevice Controller ASSERT: 53, 296\033[0m
[00:04:57.431,335] \033[1;31m<err> os: ***** HARD FAULT *****\033[0m
[00:04:57.431,335] \033[1;31m<err> os:   Fault escalation (see below)\033[0m
[00:04:57.431,365] \033[1;31m<err> os: ARCH_EXCEPT with reason 3
\033[0m
[00:04:57.431,365] \033[1;31m<err> os: r0/a1:  0x00000003  r1/a2:  0x00000000  r2/a3:  0x0001981b\033[0m
[00:04:57.431,396] \033[1;31m<err> os: r3/a4:  0x00000000 r12/ip:  0x20000ab0 r14/lr:  0xffffffff\033[0m
[00:04:57.431,396] \033[1;31m<err> os:  xpsr:  0x41000011\033[0m
[00:04:57.431,396] \033[1;31m<err> os: r4/v1:  0x20015c70  r5/v2:  0x0003370d  r6/v3:  0x0000000a\033[0m
[00:04:57.431,427] \033[1;31m<err> os: r7/v4:  0x20015c70  r8/v5:  0x20001944  r9/v6:  0x2000e204\033[0m
[00:04:57.431,427] \033[1;31m<err> os: r10/v7: 0x200008bc  r11/v8: 0x00000000    psp:  0x20015f40\033[0m
[00:04:57.431,457] \033[1;31m<err> os: EXC_RETURN: 0xfffffff1\033[0m
[00:04:57.431,457] \033[1;31m<err> os: Faulting instruction address (r15/pc): 0x00033744\033[0m
[00:04:57.431,488] \033[1;31m<err> os: >>> ZEPHYR FATAL ERROR 3: Kernel oops on CPU 0\033[0m
[00:04:57.431,518] \033[1;31m<err> os: Fault during interrupt handling
\033[0m
[00:04:57.431,549] \033[1;31m<err> os: Current thread: 0x2000ae30 (unknown)\033[0m
[00:05:09.972,747] \033[1;31m<err> fatal_error: Resetting system\033[0m

When this happens it is in the process of uploading a new fw thru mcumgr image group, upload command.

I haven't been able to fully verify this but I think this affected by updating to SDK 2.6.0 (from 2.4.0).
That code part is unchanged before and after the SDK update except that "zcbor_new_decode_state" had two new parameter which we have set to NULL and 0 (after comparing how some examples had changed between sdk versions).

BR,
Mårten

[Einar Thorsrud]

Hi Mårten,

The assert is triggered by an "overstay" event in the SoftDevice controller scheduling related to BLE central operation. So something has prevetned that code from running on time. That something can be higher priority threads or interrupts. I cannot say anything more specific based on the assert, but perhaps disconnect any central links when initiating DFU?

[Maos]

Hi!

Thanks for the reply.

Maybe wasn't that clear but the assert is happening on the central that is sending the image to a peripheral.
There is only one connection doing an update and possibly one more connection simultaneously (to different peripheral device) sending a smaller amount of data.

I have however managed to reproduce the issue with just a single peripheral.

Is there some "bluetooth" thread where the priority can be raised?

I guess this is deeper down and therefore not connected to what is done in the callback passed to bt_dfu_smp_command?

BR,
Mårten

[AHaug]

Hi Mårten,

No worries, glad you found a middle ground that works for you. The patch will nonetheless be added to main shortly

Kind regards,
Andras

[mertzt]

Has this been addressed?

I am encountering the same assert on my project using an NRF5340 and NCS v2.6.1.

[AHaug]

Hi,

The fix is in NCS v2.8.0 and was determined previously to not be back ported to v2.6.1. 

If you need it back ported, please reach out to your regional sales manager and request it through them

Kind regards,
Andreas

[mertzt]

I've reached out to our local sales manager to request the backport. In the meantime, we are trying to gather as much information as possible.

• Do you have any additional information about what commits address the issue?
• Are there any known workarounds?

Thanks,
Tim

[AHaug]

Hi Tim,

I can verify that I've seen the discussion this has raised. I will monitor it.

Since the fix is within non-open source code material, I can't share anything about the commit here. The best approach willl thus be to keep in touch with the sales manager and/or raise your own private case (with relevant company info and request info)

Kind regards,
Andreas