# WP7702 Crashes when using NB-IoT **URL:** https://forum.sierrawireless.com/t/wp7702-crashes-when-using-nb-iot/17410 **Category:** WP Series **Created:** [August 28, 2019, 10:02am UTC](https://forum.sierrawireless.com/t/wp7702-crashes-when-using-nb-iot/17410 "2019-08-28T10:02:18Z") **Posts on this page:** 1 **Page:** 1
### Author: ![thomas](https://avatars.discourse-cdn.com/v4/letter/t/e36b37/32.png) [@thomas](https://forum.sierrawireless.com/u/thomas) #### Post date: [August 28, 2019, 10:02am UTC](https://forum.sierrawireless.com/t/wp7702-crashes-when-using-nb-iot/17410/1 "2019-08-28T10:02:18Z")
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](http://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](http://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](http://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](http://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](http://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