Hi,
Is there some known issue with FW version 01.14.03.00? We have encountered several EM7421 modems that have ended up in bootloader mode (usb bus id 1199:9090**). It seems that all modems that have failed like this, are running FW version 01.14.03.00. With FW version 01.14.22.00 we haven’t noticed this problem at least yet. Are we safe from this with FW version 01.14.22.00?**
br, Sami
What is the return of at!gcdump when crash with old firmware?
There is no at-port available so I can’t tell.
This is from modem that had that issue, but I updated the FW so that I can access the at-port again.
at!gcdump
Src: FatalError
Str: Attempted to kill init! exitcode=0x0000000b
00000000 00000000 00000000 00000000
Prc: APSS
Task: C5978FC0
Time: 00000000
R0: 00000000 R1: 00000000 R2: 00000000 R3: 00000000 R4: 00000000
R5: 00000000 R6: 00000000 R7: 00000000 R8: 00000000 R9: 00000000
R10: 00000000 R11: C50A3EBC R12: 00000000 R13: C50A3E90 R14: C0011DC4
PC: C001483C
CPSR: 00000000
Mod: Unknown
TOS
C0011DC4 A516BDAB C001F1E8 00000023 C07BF984 C0E124F8 C0A1D204
00000000 001190D8 C50A3F88 C001F298 00000000 00000023 C0A18DB4
C07BF984 00000001 C1067DF8 00000000 C07DD134 C50A3F88 00000001
C0E9508C C65FB100 00000001 C013A994 C50A3F88 001190D8 00000002
00000002 00000002 C57F5B40 001190D8
BOS
OK
Not sure if that is a valid information anymore..
Suggest you using the old firmware to reproduce the crash first
Well, how can I access the at-port then? It doesn’t exist.
Did you install the correct usb driver?
Yes, drivers are correct. They are from MBPL R41.
Then did you compare dmesg on why there is no AT port?
No I didn’t. But isn’t it obvious that modem has failed to start it’s application. It appears on bus with wrong id which means that it is waiting for FW. I’ve seen this before and only way to recover is to use fwdwl to rewrite FW to modem.
This does not make sense as the firmware cannot even start in your platform
But if your test shows new firmware can start, then you can use it in your platform ( of course you will not know the root cause)
Yes. But the question is that is there some known issue with that old FW that can cause this? Or should we still expect similar thing to happen even with newer FW? This is a big problem for us as modems die while they are being delivered to our customers..
Didn’t your test show that the new firmware has no problem?
Actually i think your platform has some unknown problem on the old firmware, you can put the old firmware to a windows pc or linux pc, it should be ok to boot up
I have one faulty EM7421 on hand and I connected it to win11 laptop. It didn’t react at all to it. I couldn’t see anything on device manager. I then put it on linux pc (ubuntu 22.04). There it behaves just like on our device. Only one ttyUSBx created, usb bus id incorrect:
Bus 001 Device 012: ID 1199:9090 Sierra Wireless, Inc. Sierra Wireless EM7421 Qualcomm® Snapdragonâ
what is the purpose to test on a faulty module?
I thought that it was what you wanted to see “you can put the old firmware to a windows pc or linux pc, it should be ok to boot up“
But maybe you meant that modem with old firmware (that is not corrupted) should work on win or linux pc. It does, of course. And it works on our device too. Until it doesn’t. We have seen several EM7421 modems that corrupt their FW and doesn’t boot anymore. And our understanding is, that modules with FW version 01.14.03.00 are more likely to end up in this state. Not sure if that is the case and that’s why I was asking if there is some known issue with that older FW version.
then did you reproduce the issue on windows PC or linux PC with good module with old firmware?
No I haven’t because I don’t know how to reproduce it. It happens when it happens but we don’t know why it happens.
then it is quite hard to know the root cause.
Maybe you can set up two environment for particular period of time to see what happens: