HP lt4120 failing to make single-stack connections on LTE using MM

[Aleksander Morgado]

Hey,

>
> I have an 'HP lt4120 Snapdragon X5 LTE' WWAN module running firmware
> revision 'T77W595.F0.0.0.6.6.GC.029  1  [Jul 06 2016 23:00:00' (latest
> available on HP's web site).
>
> It tends to frequently get to a state where MM fails to establish single-
> stack connections while in LTE coverage. I'm pretty sure it's not a
> network or subscription problem as the problem is there in different
> PLMNs and SIM cards from different operators, and it works fine using
> other UEs like Android and Jolla phones. I've set up the 3GPP profile
> like so:
>
> $ sudo qmicli -p -d /dev/cdc-wdm0 --wds-get-profile-list=3gpp
> Profile list retrieved:
>         [1] 3gpp - profile1
>                 APN: 'telenor.smart'
>                 PDP type: 'ipv6'
>                 Auth: 'none'
>
> Using qmicli it seems to connect without problems:
>
> $ sudo qmicli -p -d /dev/cdc-wdm0 --wds-start-network=3gpp-profile=1
> [/dev/cdc-wdm0] Network started
>         Packet data handle: '68385664'
>
> But MM fails (and so does NM):
>
> $ sudo /usr/bin/mmcli -m 0 --simple-connect=apn=telenor.smart,ip-type=ipv6
> error: couldn't connect the modem: 'Timeout was reached'
>
> This results in the following being logged:
>
> <info>  Simple connect started...
> <info>  Simple connect state (4/8): Wait to get fully enabled
> <info>  Simple connect state (5/8): Register
> <info>  Simple connect state (6/8): Bearer
> <info>  Simple connect state (7/8): Connect
> <info>  Modem /org/freedesktop/ModemManager1/Modem/0: state changed (registered -> connecting)
> <info>  Modem /org/freedesktop/ModemManager1/Modem/0: state changed (connecting -> registered)
> [/dev/cdc-wdm0] No transaction matched in received message
> [/dev/cdc-wdm0] Received unexpected message (translated)...
>>>>>>> Header:
>>>>>>>   length      = 76
>>>>>>>   type        = command-done (0x80000003)
>>>>>>>   transaction = 31
>>>>>>> Fragment header:
>>>>>>>   total   = 1
>>>>>>>   current = 0
>>>>>>> Contents:
>>>>>>>   status error = 'Failure' (0x00000002)
>>>>>>>   service      = 'basic-connect' (a289cc33-bcbb-8b4f-b6b0-133ec2aae6df)
>>>>>>>   cid          = 'packet-service' (0x0000000a)
>
> It only happens in LTE coverage, UMTS and GSM has no issues at all. Also
> it only seems to happen with the single-stack IP types (both IPv4- and
> IPv6-only), never with dual-stack.
>
> Anyone seen something like this before and have any suggestion on how to
> avoid/prevent it?
>

No idea, sorry.

> If I power down my laptop completely and bring it back up, that might
> might shake it loose for a while, but my test scripts that iterates
> through all PLMNs and all RATs and tries to connect in each using all
> three IP types will usually get it back in the stuck state again.
>
> Is there a way to fully power cycle the WWAN module without
> powercycling the entire laptop, by the way?
>

$ sudo mmcli -m 0 --reset

-- 
Aleksander
https://aleksander.es