NRF9160 Modem Frozen after put into Offline Mode

[mlang3440]

I have seen some situations where putting the modem into offline mode (CFUN=4) will cause my application to lock up because the at_cmd never returns. It looks like this is a pre-existing problem as reported here https://devzone.nordicsemi.com/f/nordic-q-a/52819/nrf9160-modem-not-responding-after-switching-to-offline-mode. However we are using modem firmware 1.1 and not using eDRX.

Is there any solution to this issue? We are seeing it fairly frequently, and have to reset the device when it happens.

Thanks

[Sigurd]

Hi,

As mentioned by Håkon here, this was an issue with the NCS codebase. Let me know if updating your codebase to NCS v1.1.0 does not fix the issue.

[mlang3440]

We are using NCS 1.1.0. Do you know what part of the NCS code base was the cause of this?

[Sigurd]

mlang3440 said:

Do you know what part of the NCS code base was the cause of this?

 The issue in the post you linked to, was fixed as part of this PR: https://github.com/NordicPlayground/fw-nrfconnect-nrf/pull/1242

some situations where putting the modem into offline mode

 How often does this happens ? 

Could you upload the log output from LTE-Link monitor when the issue happens?