# usb mobile broadband modem connectivity lost after update

## freifunk_connewitz

hi,

on my laptop, I used the builtin 3G-mobile broadband modem every once in a while. it has worked quite well, but now, after not having used it for about 2 months (and after the usual weekly updates), NetworkManager just does not find any mobile broadband modem any more. also if I try to configure a new connection, the wizard's page where you choose the device has only an empty device list to offer.

somehow the modem init process stops after the Qualcomm Modem Converter gets attached to /dev/ttyUSB0 - 2. but no network device wwan0 gets activated.

here's my setup:

machine: Fujitsu Lifebook S 761

modem: Sierra Wireless MC 8035 (ID: 1199:9011)

kernel: 3.14.14-gentoo

NetworkManager: 0.9.8.10-r1

ModemManager: 1.2.0-r1

```

# lsmod

iptable_nat             2486  0 

nf_nat_ipv4             3038  1 iptable_nat

nf_nat                  9935  2 nf_nat_ipv4,iptable_nat

ext4                  395734  1 

jbd2                   69582  1 ext4

qcserial                6756  0 

qmi_wwan               13435  0 

cdc_wdm                 8897  1 qmi_wwan

usb_wwan                5423  1 qcserial

usbnet                 17418  1 qmi_wwan

usbserial              19565  2 qcserial,usb_wwan

mii                     3347  1 usbnet

uvcvideo               61509  0 

videobuf2_vmalloc       2496  1 uvcvideo

videobuf2_memops        1511  1 videobuf2_vmalloc

videobuf2_core         22899  1 uvcvideo

videodev              103395  2 uvcvideo,videobuf2_core

media                  10139  2 uvcvideo,videodev

vboxnetflt             13314  0 

vboxnetadp             17206  0 

vboxdrv               289295  2 vboxnetadp,vboxnetflt

snd_hda_codec_hdmi     30915  1 

snd_hda_codec_realtek    41292  1 

snd_hda_codec_generic    41273  1 snd_hda_codec_realtek

x86_pkg_temp_thermal     4390  0 

coretemp                5534  0 

kvm_intel             120475  0 

kvm                   316606  1 kvm_intel

iwldvm                102291  0 

crc32_pclmul            2627  0 

crc32c_intel           13770  0 

snd_hda_intel          29705  2 

sdhci_pci               9933  0 

ghash_clmulni_intel     3483  0 

iwlwifi                65383  1 iwldvm

sdhci                  20488  1 sdhci_pci

snd_hda_codec          80250  4 snd_hda_codec_realtek,snd_hda_codec_hdmi,snd_hda_codec_generic,snd_hda_intel

i2c_i801                8536  0 

mmc_core               74234  1 sdhci

snd_hwdep               5197  1 snd_hda_codec

ehci_pci                3176  0 

snd_pcm                66456  3 snd_hda_codec_hdmi,snd_hda_codec,snd_hda_intel

e1000e                136355  0 

ehci_hcd               35189  1 ehci_pci

snd_timer              15576  1 snd_pcm

snd                    50067  12 snd_hda_codec_realtek,snd_hwdep,snd_timer,snd_hda_codec_hdmi,snd_pcm,snd_hda_codec_generic,snd_hda_codec,snd_hda_intel

ptp                     6748  1 e1000e

pps_core                5728  1 ptp
```

if I try the modules sierra or sierra_net, Networkmanager can't even connect the cable connection anymore. but those modules weren't even present when the 3G connection was still working. IIRC it only needed qcserial, usbserial and usb_wwan.

I already tried to compile the QMI, USBNET and CDC modules which are already present in the loaded modules list above. I even tried to manually bring up the device wwan0 (no error message when doing so, BTW). but still, there is no mobile broadband device available to NetworkManager.

can anybody help me by pushing me in the right way to think and try?  thanks a lot.

----------

## eccerr0r

I didn't see your ppp module, did you build it in the kernel?

----------

## freifunk_connewitz

eccerr0r, 

thanks for the reply. 

no, ppp is built as a module here:

```
# cat /usr/src/linux/.config|grep PPP

CONFIG_PPP=m

CONFIG_PPP_BSDCOMP=m

CONFIG_PPP_DEFLATE=m

CONFIG_PPP_FILTER=y

CONFIG_PPP_MPPE=m

CONFIG_PPP_MULTILINK=y

CONFIG_PPPOE=m

CONFIG_PPP_ASYNC=m

CONFIG_PPP_SYNC_TTY=m

CONFIG_HDLC_PPP=m

```

----------

## freifunk_connewitz

hi again,

an update so maybe my problem is better understandable:

the modem gets started during boot and the /dev/ttyUSB0-2 devices get initialized. when I 

```
cat /dev/ttyUSB1
```

and 

```
echo "ATi^M" >/dev/ttyUSB1
```

 in another terminal, the modem responds in the first terminal:

 *Quote:*   

> # cat /dev/ttyUSB1
> 
> ATi
> 
> Manufacturer: Sierra Wireless Inc
> ...

 

BUT there is still no wwan-device showing up in NetworkManager or after

```
rfkill list
```

.

What am I missing? Especially since my setup has been working until recently.

----------

## freifunk_connewitz

Hi again,

how embarassing that I didn't think of that, but the problem is much more on top of all layers than I thought:

As described here:

https://forums.gentoo.org/viewtopic-p-7611012.html#7611012,

with the last update (in my case to 0.9.8.10-r1) NetworkManager did not start Modemmanager any more.

 *Quote:*   

> # emerge --info networkmanager
> 
> Portage 2.2.8-r1 (default/linux/amd64/13.0/desktop/kde, gcc-4.7.3, glibc-2.19-r1, 3.14.14-gentoo x86_64)
> 
> =================================================================
> ...

 

----------

