Huawei ME906s-158 (a.k.a. HP lt4132) IPv6 support

[Tore Anderson]

* Bjørn Mork

> I don't know if this will help Tore much anyway.  I did some testing
> with the E392 to confirm that I remembered correctly: This modem does
> *not* change the output of any command when IPv6 is disabled.  The only
> visible difference is that IPv6 connections fail.  You can still
> configure them.

Now I've tried running the tool, both the patched version and the
original in the MM git repo, on every single /dev/ttyUSB* that show up
in all three bConfigurationValues with no special USB serial module
loaded and also with option.ko, qcaux.ko, and qcserial.ko. All possible
permutations of the above I tried in a scripted manner.

Most of the time the tool fails with:

E: failed to receive QCDM IPv6 pref command reply
E: failed to get IPv6 state

Sometimes it instead crashes, saying only:

ipv6pref.c:105: qcdm_send: Assertion `errno == 0' failed.

It never actually did anything resembling a successful operation. I
suppose that means the the tool, patched or not, simply does not support
the ME906s-158.

> In the current state, with IPv6 enabled, everything works on the E392:
> 
> root at miraculix:/tmp# qmicli -d /dev/cdc-wdm1  --wds-start-network=apn=telenor.smart,ip-type=6  --wds-follow-network

No cigar:

$ qmicli -d /dev/cdc-wdm0 --wds-start-network=apn=telenor.smart,ip-type=6 --wds-follow-network
error: couldn't create client for the 'wds' service: CID allocation failed in the CTL client: MBIM error: Transaction timed out

The other qmicli commands you pasted doesn't work either.

> This behaviour is so different from the symptoms Tore see, that I doubt
> there is any relation.  Still, it can't harm to test if the attached
> patch allows writing anything that NV item...  Or it can harm - I never
> give out gurantees when it comes to arbitrary NVRAM writes ;-)

I really appreciate the input, thank you. But unfortunately I think the
conclusion is that there is no hope to make IPv6 work on this modem,
unless Huawei or HP support returns to me with some magic trick to
enable it.

The good news is that HP support agreed to replace my lt4132 with a
lt4120, which is a Foxconn device that I hope works better.

Tore