No serial ports for MC7304 after FW Upgrade

Hi,

I have a MC7304 upgraded to SWI9X15C_05.05.58.00_GENEU-4G_005.029_000. And after upgrade, no serial ports show up neither on Windows nor on Linux.

On Windows, I’ve tried different driver versions. Namely v4773, v4277, v4431 and v4743. It does show up as Mobile Broadband Device, but nothing else.

Linux behaves similarly.

Here’s output of dmesg, after inserting the device:

[73756.008036] usb 1-1: new high-speed USB device number 4 using ehci-pci
[73756.122839] usb 1-1: config 1 has an invalid interface number: 12 but max is 1
[73756.122846] usb 1-1: config 1 has an invalid interface number: 13 but max is 1
[73756.122850] usb 1-1: config 1 has an invalid interface number: 13 but max is 1
[73756.122854] usb 1-1: config 1 has no interface number 0
[73756.122858] usb 1-1: config 1 has no interface number 1
[73756.123593] usb 1-1: New USB device found, idVendor=1199, idProduct=68a2
[73756.123599] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
[73756.123604] usb 1-1: Product: MC7304
[73756.123608] usb 1-1: Manufacturer: Sierra Wireless, Incorporated
[73756.125840] cdc_mbim 1-1:1.12: cdc-wdm0: USB WDM device
[73756.126048] cdc_mbim 1-1:1.12 wwan0: register 'cdc_mbim' at usb-0000:00:1d.7-1, CDC MBIM, d2:2b:2f:b5:2d:7f

I’ve tried compiling Gobi drivers, and inserting the modules into kernel to little success.

I’ve tried blacklisting the cmc_mbim, cdc_acm, and cdc_ncm modules, but no driver is loaded for device then.

Windows is 10 1709
Linux kernel is 3.10.0-229.14.1.el7.x86_64

What am I doing wrong?

PS
Here’s also output of lsusb -v, regarding the device:

Bus 001 Device 006: ID 1199:68a2 Sierra Wireless, Inc. 
Device Descriptor:
  bLength                18
  bDescriptorType         1
  bcdUSB               2.00
  bDeviceClass            0 (Defined at Interface level)
  bDeviceSubClass         0 
  bDeviceProtocol         0 
  bMaxPacketSize0        64
  idVendor           0x1199 Sierra Wireless, Inc.
  idProduct          0x68a2 
  bcdDevice            0.06
  iManufacturer           1 Sierra Wireless, Incorporated
  iProduct                2 MC7304
  iSerial                 3 
  bNumConfigurations      1
  Configuration Descriptor:
    bLength                 9
    bDescriptorType         2
    wTotalLength           95
    bNumInterfaces          2
    bConfigurationValue     1
    iConfiguration          0 
    bmAttributes         0xe0
      Self Powered
      Remote Wakeup
    MaxPower              500mA
    Interface Association:
      bLength                 8
      bDescriptorType        11
      bFirstInterface        12
      bInterfaceCount         2
      bFunctionClass          2 Communications
      bFunctionSubClass      14 
      bFunctionProtocol       0 
      iFunction               0 
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber       12
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         2 Communications
      bInterfaceSubClass     14 
      bInterfaceProtocol      0 
      iInterface              0 
      CDC Header:
        bcdCDC               1.10
      CDC Union:
        bMasterInterface        12
        bSlaveInterface         13 
      CDC MBIM:
        bcdMBIMVersion       1.00
        wMaxControlMessage   4096
        bNumberFilters       32
        bMaxFilterSize       128
        wMaxSegmentSize      1430
        bmNetworkCapabilities 0x20
          8-byte ntb input size
      UNRECOGNIZED CDC:  08 24 1c 00 01 40 dc 05
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x82  EP 2 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0040  1x 64 bytes
        bInterval               9
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber       13
      bAlternateSetting       0
      bNumEndpoints           0
      bInterfaceClass        10 CDC Data
      bInterfaceSubClass      0 Unused
      bInterfaceProtocol      2 
      iInterface              0 
    Interface Descriptor:
      bLength                 9
      bDescriptorType         4
      bInterfaceNumber       13
      bAlternateSetting       1
      bNumEndpoints           2
      bInterfaceClass        10 CDC Data
      bInterfaceSubClass      0 Unused
      bInterfaceProtocol      2 
      iInterface              0 
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x01  EP 1 OUT
        bmAttributes            2
          Transfer Type            Bulk
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0200  1x 512 bytes
        bInterval               0

Someone should probably add this to the FAQ… It’s been answered multiple times in this forum. See for example:
https://forum.sierrawireless.com/t/solved-ttyusb-not-created-w-ubuntu-or-qmi-drivers-em7355/9644/1