Legato R12 shutdown when mobile data connection drops


I installed Sierra Wireless R12 on my WP7607 device. (based upon Legato 18.10.3 and Linux Yocto 3.18.122)
I didn’t install any additional apps.

I use the command line tool ‘cm’ to configure my sim and apn settings, and I can create a mobile data connection to our APN network. ‘cm radio’ shows that the target is registered to the home network, and shows an excellent signal quality.
I execute a ping towards our server on the APN network, and I receive feedback as expected.

Then, I perform the following test:
I disconnect the MAIN antenna from the target board, to simulate signal/network problems.
‘cm radio’ shows that the signal quality drops to 0, and the target can’t register to the network anymore.
‘ping’ replies: “Network is unreachable”
To my opinion, this is expected behaviour.

But then, after a few seconds, the Legato system goes down and the SSH connection between host PC and target board is lost.
I can only create a new SSH connection after I disconnect/connect the supply of the target board.

I performed this test for more than 20 times, and each time the Legato system goes down when I disconnect the antenna.

The syslog does not indicate detailed info concerning this issue, so, I don’t have a clue how this can be fixed.

*swi-mdm9x28-wp user.info swiapp: qmi_at_unsol_ind_cb: ind id:33 *
swi-mdm9x28-wp user.info swiapp: Received AT command forward request from modem
swi-mdm9x28-wp user.info swiapp: fwdcmd.opcode=1
swi-mdm9x28-wp user.info swiapp: fwdcmd.name=$QCPWRDN
swi-mdm9x28-wp user.info swiapp: fwdcmd.ntokens=0
swi-mdm9x28-wp user.info swiapp: ctrCond signalling complete.
swi-mdm9x28-wp user.info swiapp: Recieved ctrCond: p: 0, S:0, nr: 1
swi-mdm9x28-wp user.info swiapp: QCPWRDN has been detected
swi-mdm9x28-wp user.warn kernel: [ 218.938891] PSM: Modem oprt mode - 3


syslog legato shutdown when mobile data connection drops - 20190522.txt (381.3 KB)

@annaertd You need to see if any of the default apps are set to reboot on a fault. This will close the SSH connection. Look in each .adef file for faultAction: reboot in the processes section of the file. If you change this to faultAction: restartApp then only app is terminated and restarted.

Also I have noticed that when my module reboots it takes some time before the ssh server is started.

Hi @annaertd,
Do you still see this issue? As @dbeckwith mentioned, Any of your App’s ‘faultAction’ was set to ‘reboot’ ? I don’t think because as you mentoned you have not installed additional app and also in the default Legato-18.10.3 i don’t see any App’s ‘faultAction’ is set to ‘reboot’ .

BTW, i tried to simulate your issue using the R12(Legato-18.10.3), But i couldn’t reproduce the issue.

Also i analyzed the logs which you have attached, I don’t find any information from the logs why the legato-af stopped. In fact from the logs i see only boot up sequence and legato services/apps starting.

If you still the issue, Please provide the complete debug legato logs(log level DEBUG) starting from opening the data connection to legato system stopping/rebooting.

Muralidhara N.

the issue is still there, and I’m convinced that there could be a link with my other crash issue:

The only useful stuff I can find in my logs, is modemDaemon service-calls just before the reboot.
Unfortunately it doesn’t contain enough info for me to understand what’s going wrong.

syslog sample 2 - 20190604 11u58.txt (38.6 KB) syslog sample 2 - 20190605 15u22.txt (4.1 KB) syslog sample 2 - 20190606 17u09.txt (20.8 KB) syslog sample 3 - 20190604 09u24.txt (124.5 KB) syslog sample 4 - 20190605 11u02.txt (125.3 KB)


@annaertd, I’m having the same issue and my logs are pretty much the same as yours. I don’t have any custom applications running with the base Legato apps. Did you find any resolution regarding this problem?