MC7421 unexpected reset

IoT Modules MC/EM Series
1

Hello,
I have a private SIM CARD (with APN, username and password with auth type is CHAP )
for the first time it worked without issue but now when I enter the pin code the MC7421 resets
did you see this issue before and how to resolve it
here modem log
atexecute ttyUSB2 “ATI”
ATI
Manufacturer: Sierra Wireless, Incorporated
Model: MC7421
Revision: SWI9X50C_01.14.03.00 b06bd3 jenkins 2020/09/23 10:53:35
IMEI: 357339340291369
IMEI SV: 13
FSN: 912116252704B1
+GCAP: +CGSM,+DS,+ES

OK

qmicli --device=/dev/cdc-wdm0 --device-open-proxy --wds-get-profile-list=3gpp
Profile list retrieved:
[1] 3gpp -
APN: ‘MobileIP-VPN’
PDP type: ‘ipv4’
PDP context number: ‘1’
Username: ‘966830040168068’
Password: ‘966830040168068’
Auth: ‘chap’
No roaming: ‘yes’
APN disabled: ‘no’

AT+CGDCONT?
+CGDCONT: 1,“IP”,“MobileIP-VPN”,“0.0.0.0”,0,0,0,0

OK
atexecute ttyUSB2 “AT!GCDUMP”
AT!GCDUMP

Src: Exception
Str: ExIPC: Exception recieved tid=7a inst=d038f78c
0000011C 00000000 00000000 00000000
Prc: MPSS
Task: 0000007A
Time: 000126F5
R0: 00000000 R1: 00000000 R2: 00000000 R3: 00000000 R4: 00000000
R5: 00000000 R6: 00000000 R7: 00000000 R8: 00000000 R9: 00000000
R10: 00000000 R11: 00000000 R12: 00000000 R13: 00000000 R14: 00000000
R15: 00000000 R16: 00000000 R17: 00000000 R18: 00000000 R19: 00000000
R20: 00000000 R21: 00000000 R22: 00000000 R23: 00000000 R24: 00000000
R25: 00000000 R26: 00000000 R27: 00000000 R28: 00000000 SP: C3628178
FP: 00000000 LR: 00000000
PC: D038F78C
CPSR: 00000003
Mod: Unknown
TOS
00000000 00000000 467A1DB0 467A1B78 0000004F C3628210 7B000002
00000000 00000000 00000000 00000000 00000000 00000001 00000000
7B000003 00000000 00000000 00000000 00000000 00000000 00000000
E9A30D26 4695DCF8 C45585E2 0000004F C3628276 C3628238 F9ED3AB6
00000000 0002BDC0 7B000200 00000000
BOS
App ver: SWI9X50C_01.14.03.00

OK

2

How did you enter pin code?
By at+cpin command?

3

I use qmicli or AT command both give the same result if I remove auth from the profile it will not reset but it can’t register to network
SIM card without auth works without any issue

4

can you show the AT command log with AT+CPIN from power on?

I don’t see problem with EM7421 with new FW:


ati3
Manufacturer: Sierra Wireless, Incorporated
Model: EM7421
Revision: SWI9X50C_01.14.22.00 ba8ef1 jenkins 2022/11/11 09:59:48
IMEI: 356281110312345
IMEI SV: 15
FSN: 8G223525512345
+GCAP: +CGSM


OK
at+cpin?
+CPIN: SIM PIN

OK
at+cpin="0000"
OK
5

the issue with the SIM pin is when the modem try to attach it will reboot, with other SIM card without authentication I never saw this behaviour

BW, I have MC7421 not EM7421, and I tried to upgrade the firmware, but it seems it failed to upgrade the nvu file as shown below

atexecute ttyUSB2 “AT!IMPREF?”
AT!IMPREF?
!IMPREF:
preferred fw version: 01.14.13.00
preferred carrier name: GENERIC
preferred config name: GENERIC_002.048_000
preferred subpri index: 000
current fw version: 01.14.13.00
current carrier name: GENERIC
current config name: GENERIC_002.036_010
current subpri index: 000

config name mismatch

OK

so I set it to use the old nvu

qmicli -d /dev/cdc-wdm0 -p --dms-set-firmware-preference=“firmware-version=01.14.13.00,config-version=002.036_010,carr
ier=GENERIC”

atexecute ttyUSB2 “AT!IMPREF?”
AT!IMPREF?
!IMPREF:
preferred fw version: 01.14.13.00
preferred carrier name: GENERIC
preferred config name: GENERIC_002.036_010
preferred subpri index: 000
current fw version: 01.14.13.00
current carrier name: GENERIC
current config name: GENERIC_002.036_010
current subpri index: 000

OK

I used the following to upgrade

qmicli -d /dev/cdc-wdm0 -p --dms-set-firmware-preference=“firmware-version=01.14.13.00,config-version=002.048_000,carrier=GENERIC”
atexecute ttyUSB2 AT!BOOTHOLD
qmi-firmware-update -t “/dev/ttyUSB0” -L upgrade.log --ignore-mm-runtime-check -U /tmp/SWI9X50C_01.14.13.00.cwe /tmp/SWI9X50C_01.14.13.00_GENERIC_002.048_000.nvu

qmi-firmware-update -t “/dev/ttyUSB0” -L upgrade.log --ignore-mm-runtime-check -U /tmp/SWI9X50C_01.14.13.00.cwe /tmp/SWI9X50C_01.14.13.00_GENERIC_002.048_000.nvu
downloading cwe image: SWI9X50C_01.14.13.00.cwe (80.2 MB)…
(-----*) 100.0%error: error downloading image: couldn’t write in session: couldn’t send last end-of-transfer blocktimed out waiting to write

6

Then will it reboot if you first disable sim pin by at+clck command and retry?

The difference between EM and MC is the hardware interface, but the software is the same …

You can try the MBPL fw download app

https://source.sierrawireless.com/resources/airprime/software/mbpl/mbpl-software-latest/

7

with new firmware until now it didn’t reset, do I need to update the nvu or no prob
atexecute ttyUSB2 “AT!IMPREF?”
AT!IMPREF?
!IMPREF:
preferred fw version: 01.14.13.00
preferred carrier name: GENERIC
preferred config name: GENERIC_002.036_010
preferred subpri index: 000
current fw version: 01.14.13.00
current carrier name: GENERIC
current config name: GENERIC_002.036_010
current subpri index: 000

OK

atexecute ttyUSB2 “AT!GCDUMP”
AT!GCDUMP
No crash data available

OK

atexecute ttyUSB2 “AT+CGDCONT?”
AT+CGDCONT?
+CGDCONT: 1,“IP”,“MobileIP-VPN”,“0.0.0.0”,0,0,0,0

OK

atexecute ttyUSB2 “AT$QCPDPP?”
AT$QCPDPP?
$QCPDPP: 1,2,“966830040168068”

OK
AT!GSTATUS?
!GSTATUS:
Current Time: 923 Temperature: 42
Reset Counter: 2 Mode: ONLINE
System mode: LTE PS state: Attached
LTE band: B8 LTE bw: 10 MHz
LTE Rx chan: 3700 LTE Tx chan: 21700
LTE SCC1 state:INACTIVE LTE SCC1 band: B3
LTE SCC1 bw : 20 MHz LTE SCC1 chan: 1450
LTE SCC2 state:NOT ASSIGNED
LTE SCC3 state:NOT ASSIGNED
LTE SCC4 state:NOT ASSIGNED
EMM state: Registered Normal Service
RRC state: RRC Connected
IMS reg state: No Srv

PCC RxM RSSI: -76 PCC RxM RSRP: -105
PCC RxD RSSI: -71 PCC RxD RSRP: -101
SCC1 RxM RSSI: -84 SCC1 RxM RSRP: -105
SCC1 RxD RSSI: -77 SCC1 RxD RSRP: -99
Tx Power: – TAC: 3a9e (15006)
RSRQ (dB): -10.8 Cell ID: 0ac8940c (180917260)
SINR (dB): 6.0

OK

8

Yes, you need to update both cwe and nvu file