mangOH red WP7702 crash after 30 minutes

mangOH Red
1

Hello,

I am trying to connect my WP7702 to the NB-IoT network but with no success. I don’t know if this is related, but every half an hour the WP7702 does a reboot with the following message:

[ 1840.809339] modem subsystem failure reason: nb1fw_dl_pdcch.c:1134:Assertion (cfg->ss != NB1FW_DL_PDCCH_SS_CSS_PAGE) failed.<\r><\n>
[ 1840.820576] M-Notify: General: 8<\r><\n>
[ 1840.931047] Kernel panic - not syncing: subsys-restart: Resetting the SoC - modem crashed.<\r><\n>
[ 1840.938335] CPU: 0 PID: 236 Comm: kworker/0:4 Not tainted 3.18.44 #2<\r><\n>
[ 1840.944635] Workqueue: events device_restart_work_hdlr<\r><\n>
[ 1840.949763] [] (unwind_backtrace) from [] (show_stack+0x10/0x14)<\r><\n>
[ 1840.957472] [] (show_stack) from [] (panic+0x90/0x1f4)<\r><\n>
[ 1840.964328] [] (panic) from [] (device_restart_work_hdlr+0x38/0x3c)<\r><\n>
[ 1840.972317] [] (device_restart_work_hdlr) from [] (process_one_work+0x198/0x2e4)<\r><\n>
[ 1840.981432] [] (process_one_work) from [] (worker_thread+0x2e0/0x3bc)<\r><\n>
[ 1840.989587] [] (worker_thread) from [] (kthread+0xc8/0xd4)<\r><\n>
[ 1840.996796] [] (kthread) from [] (ret_from_fork+0x14/0x3c)<\r><\n>
[ 1841.004003] cpr_panic_callback: apc_corner: [corner:7, fuse_corner:3] = 1250000 uV<\r><\n>
[ 1841.011671] Rebooting in 5 seconds…<\r><\n>
[ 1846.044626] Going down for restart now<\r><\n>
[ 1846.048116] reboot: trigger wdog bite<\r><\n>
[ 1846.051153] Causing a watchdog bite!Android Bootloader - UART_DM Initialized!!!<\r><\n>

2

I had similar issues with the WP7702 on an AT&T LTE-M1 connection. Crash & reboot at random intervals from 60seconds through 30-40minutes. After 4 weeks of debug, analysis & rebuilding of everything multiple times I banged on SW and they finally acknowledged an Modem Firmware instability issue that they’re know about and are working on. This was months ago and no resolution nor indication of one. I was forced to move on to another platform. Here is the link to this issue: Intermittent WP7700 module Failure: [Fatal error on the modem]

Good luck!
Mike

3

Hi Mike.

What platform have you moved to?
The instability of the WP77XX has been the biggest headache for me, I’d love to know what you are using now and how it compares.

4

I was able to reproduce the modem failure. I opened a new thread in the Sierra Wireless embedded module forum since the problem is not mangOH related. The thread is still stuck in their spam filter but I will add a link here as soon the thread is available.

Edit: Here is the link:
https://forum.sierrawireless.com/t/wp7702-crashes-when-using-nb-iot/17410/2