Fibocom L850-GL hangs upon connect.

[Daniel Wood]

I have been given a Fibocom L850-GL that seems to be stuck in NCM mode.
As I have not had any luck changing the mode back to MBIM:
ModemManager[25270]: <debug> [1533696762.104669] (ttyACM0): -->
'AT+GTUSBMODE?<CR>'
ModemManager[25270]: <debug> [1533696762.121517] (ttyACM0): <--
'<CR><LF>+CME ERROR: 4<CR><LF>'
ModemManager[25270]: <debug> [1533696831.512880] (ttyACM0): -->
'AT+GTUSBMODE=2<CR>'
ModemManager[25270]: <debug> [1533696831.530829] (ttyACM0): <--
'<CR><LF>+CME ERROR: 4<CR><LF>'

I figured I would try to see how it works under the latest version of
ModemManager, but as soon as you try to actually connect to the internet,
the serial port locks up. Now, given the state of this modem, it may have
nothing to do with ModemManager. Since it may possibly or this may assist
in adding support for these Intel XMM based chipsets, I have collected all
the information I could think of to make it available to you guys,
including debug logs and bus trees.

[85855.509892] usb 2-1.5: New USB device found, idVendor=8087,
idProduct=07f5
[85855.509896] usb 2-1.5: New USB device strings: Mfr=0, Product=0,
SerialNumber=0
[85856.714197] usb 2-1.5: USB disconnect, device number 43
[85861.288570] usb 2-1.5: new high-speed USB device number 44 using ehci-pci
[85861.405658] usb 2-1.5: New USB device found, idVendor=8087,
idProduct=095a
[85861.405662] usb 2-1.5: New USB device strings: Mfr=1, Product=2,
SerialNumber=3
[85861.405665] usb 2-1.5: Product: MODEM + 2 CDC-ACM + 3 CDC-NCM + SS
[85861.405667] usb 2-1.5: Manufacturer: Intel Corp.
[85861.405669] usb 2-1.5: SerialNumber: 004999010640000


It is 3000+ lines of info, so I created a Gist:
https://gist.github.com/danielewood/1022919b7547c50fb514a652aa3ec1f3

Let me know if there is any other information that is needed and I'll pull
it. Also, I can create a temporary linux install on a junk USB drive and
provide you with remote ssh access to the machine if someone wants to have
full access and do whatever they want. The broadband plan is unlimited, so
I'm not at all worried bandwidth use.

I also decided to compile ModemManager from the git master branch, those
results are at the end of the page.

Thanks,
-Dan
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