WP7702 Crashes when using NB-IoT

Hi,

I am trying to connect to the NB-IoT network but unfortunately the modem crashes after setting the RAT to LTE. The connection is working fine via GSM, but after switching to LTE the OS crashes and reboots. After the reboot it still crashes until I remove the SIM card and set back the RAT to GSM. Here are the logs from what I encounter:

root@swi-mdm9x28-wp:~# cm info
Device: WP7702
IMEI: 352653090137092
IMEISV: 3
FSN: VU838385130610
Firmware Version: SWI9X06Y_02.22.02.00 1d0e5e jenkins 2018/11/07 03:09:20
Bootloader Version: SWI9X06Y_02.22.02.00 1d0e5e jenki[ 1008.556432] i2c-msm-v2 78b8000.i2c: NACK: slave not responding, ensure its powered: msgs(n:1 cur:0 tx) bc(rx:0 tx:2) mode:FIFO slv_addr:0x3a MSTR_STS:0x0c1300c8 OPER:0x00000090
ns 2018/11/07 03:09:20
MCU Version: 002.011
PRI Part Number (PN): 9907365
PRI Revision: 001.006
Carrier PRI Name: GENERIC
Carrier PRI Revision: 001.041_001
SKU: 1103530
Last Reset Cause: Reset, User Requested
Resets Count: Expected: 37<9>Unexpected: 29

root@swi-mdm9x28-wp:~# cm radio
Power: ON
Current Network Operator: Telekom.de
Current RAT: GSM network (LE_MRC_RAT_GSM)
Status: Registered to a roaming network (LE_MRC_REG_ROAMING)
Signal: Very strong signal strength (5)
PS: Packet Switched Registered, home network (LE_MRC_REG_HOME)

root@swi-mdm9x28-wp:~# cm radio getRAT
Prefered RATs : GSM

root@swi-mdm9x28-wp:~# cm radio rat LTE

after 1s:

root@swi-mdm9x28-wp:~# cm radio
Power: ON
Current Network Operator: Telekom.de
Current RAT: GSM network (LE_MRC_RAT_GSM)
Status: Registered to a roaming network (LE_MRC_REG_ROAMING)
Signal: Strong signal strength (4)
PS: Packet Switched Registered, home network (LE_MRC_REG_HOME)

after 2s:

root@swi-mdm9x28-wp:~# cm radio
Power: ON
Current Network Operator: Telekom.de
Current RAT: Module not registered on network, RAT not available
Status: Not registered but currently searching for a new operator (LE_MRC_REG_SEARCHING)
Signal: No signal strength (0)
PS: Packet Switched Not registered (LE_MRC_REG_NONE)

after 3s:

root@swi-mdm9x28-wp:~# cm radio
Power: ON
Current Network Operator: Telekom.de
Current RAT: Module not registered on network, RAT not available
Status: Not registered but currently searching for a new operator (LE_MRC_REG_SEARCHING)
Signal: Weak signal strength (2)
PS: Packet Switched Not registered (LE_MRC_REG_NONE)

after 4s:

root@swi-mdm9x28-wp:~# cm radio
Power: ON
Current Network Operator: Telekom.de
Current RAT: LTE network (LE_MRC_RAT_LTE)
Status: Registered to a roaming network (LE_MRC_REG_ROAMING)
Signal: Very weak signal strength (1)
PS: Packet Switched Registered to a roaming network (LE_MRC_REG_ROAMING)

then:

root@swi-mdm9x28-wp:~# [ 1053.108484] Fatal error on the modem.
[ 1053.111136] modem subsystem failure reason: nb1fw_dl_pdcch.c:1134:Assertion (cfg->ss != NB1FW_DL_PDCCH_SS_CSS_PAGE) failed.
[ 1053.122503] M-Notify: General: 8
[ 1053.230336] Kernel panic - not syncing: subsys-restart: Resetting the SoC - modem crashed.
[ 1053.237619] CPU: 0 PID: 2577 Comm: kworker/0:3 Tainted: G O 3.18.44 #2
[ 1053.245135] Workqueue: events device_restart_work_hdlr
[ 1053.250263] [] (unwind_backtrace) from [] (show_stack+0x10/0x14)
[ 1053.257979] [] (show_stack) from [] (panic+0x90/0x1f4)
[ 1053.264834] [] (panic) from [] (device_restart_work_hdlr+0x38/0x3c)
[ 1053.272823] [] (device_restart_work_hdlr) from [] (process_one_work+0x198/0x2e4)
[ 1053.281931] [] (process_one_work) from [] (worker_thread+0x2e0/0x3bc)
[ 1053.290093] [] (worker_thread) from [] (kthread+0xc8/0xd4)
[ 1053.297296] [] (kthread) from [] (ret_from_fork+0x14/0x3c)
[ 1053.304509] cpr_panic_callback: apc_corner: [corner:7, fuse_corner:3] = 1250000 uV
[ 1053.312178] Rebooting in 5 seconds…
[ 1058.345133] Going down for restart now
[ 1058.348622] reboot: trigger wdog bite
[ 1058.351659] Causing a watchdog bite!Android Bootloader - UART_DM Initialized!!!
[10] Qseecom Init Done in Appsbl version is 0x405000
[10] secure app region addr=0x87900000 size=0x280000[10] TZ App region notif returned with status:0 addr:87900000 size:2621440
[20] TZ App log region register returned with status:0 addr:82675000 size:4096
[30] Qseecom TZ Init Done in Appsbl
[30] ERROR: No devinfo partition found
[30] Neither ‘config’ nor ‘frp’ partition found
[40] ERROR: No misc partition found
[1100] SSMEM init OK[1110] ssmem_get: region 20 not exists[1190] DEBUG: cmdline has root=
[1310] Channel alloc freed
[ 0.000000] GIC CPU mask not found - kernel will fail to boot.

…reboot…

[ 23.295653] adm_alloc_cal: cal_utils_alloc_block failed, ret = -19, cal type = 10!
starting DNS forwarder and DHCP server: dnsmasq… 23.308688] call_allocs: alloc failed!
done.
Starting Dropbear SSH server: DONE
dropbear.
cat: can’t open ‘/sys/devices/virtual/android_usb/android0/f_ecm/native_ethaddr’: No such file or directory
stopping DNS forwarder and DHCP server: dnsmasq… Starting port_bridge: stopped /usr/bin/dnsmasq (pid 1183)
done.
done
starting DNS forwarder and DHCP server: dnsmasq… done.
run_getty.sh: ttyHSL1 reserved for CONSOLE
Poky (Yocto Project Reference Distro) 2.2.3 swi-mdm9x28-wp /dev/ttyHSL1
swi-mdm9x28-wp login:
[ 28.445590] i2c-msm-v2 78b8000.i2c: NACK: slave not responding, ensure its powered: msgs(n:2 cur:0 tx) bc(rx:2 tx:1) mode:FIFO slv_addr:0x55 MSTR_STS:0x001363c8 OPER:0x00000010
[ 36.187930] Fatal error on the modem.
[ 36.190582] modem subsystem failure reason: nb1fw_dl_pdcch.c:1134:Assertion (cfg->ss != NB1FW_DL_PDCCH_SS_CSS_PAGE) failed.
[ 36.201810] M-Notify: General: 8
[ 36.310328] Kernel panic - not syncing: subsys-restart: Resetting the SoC - modem crashed.
[ 36.317612] CPU: 0 PID: 758 Comm: kworker/0:31 Tainted: G O 3.18.44 #2
[ 36.325128] Workqueue: events device_restart_work_hdlr
[ 36.330256] [] (unwind_backtrace) from [] (show_stack+0x10/0x14)
[ 36.337972] [] (show_stack) from [] (panic+0x90/0x1f4)
[ 36.344827] [] (panic) from [] (device_restart_work_hdlr+0x38/0x3c)
[ 36.352810] [] (device_restart_work_hdlr) from [] (process_one_work+0x198/0x2e4)
[ 36.361924] [] (process_one_work) from [] (worker_thread+0x2e0/0x3bc)
[ 36.370086] [] (worker_thread) from [] (kthread+0xc8/0xd4)
[ 36.377289] [] (kthread) from [] (ret_from_fork+0x14/0x3c)
[ 36.384502] cpr_panic_callback: apc_corner: [corner:7, fuse_corner:3] = 1262500 uV
[ 36.392165] Rebooting in 5 seconds…
[ 41.425123] Going down for restart now
[ 41.428612] reboot: trigger wdog bite
[ 41.431649] Causing a watchdog bite!

Is this an error in the firmware?

Best regards
Thomas