Comment 31 for bug 1721909

Dell XPS 15 9570 (2018) Same issue:

lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 18.10
Release: 18.10
Codename: cosmic

uname -a
Linux noah-XPS-15-9570 4.18.0-11-generic #12-Ubuntu SMP Tue Oct 23 19:22:37 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

lsusb
Bus 002 Device 001: ID 1d6b:0003 Linux Foundation 3.0 root hub
Bus 001 Device 003: ID 27c6:5395
Bus 001 Device 002: ID 0cf3:e301 Atheros Communications, Inc.
Bus 001 Device 004: ID 0c45:671d Microdia
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

lsusb -s 001:003 -vv

Bus 001 Device 003: ID 27c6:5395
Couldn't open device, some information will be missing
Device Descriptor:
  bLength 18
  bDescriptorType 1
  bcdUSB 2.00
  bDeviceClass 239 Miscellaneous Device
  bDeviceSubClass 2 ?
  bDeviceProtocol 1 Interface Association
  bMaxPacketSize0 64
  idVendor 0x27c6
  idProduct 0x5395
  bcdDevice 1.00
  iManufacturer 1
  iProduct 2
  iSerial 3
  bNumConfigurations 1
  Configuration Descriptor:
    bLength 9
    bDescriptorType 2
    wTotalLength 75
    bNumInterfaces 2
    bConfigurationValue 1
    iConfiguration 0
    bmAttributes 0xa0
      (Bus Powered)
      Remote Wakeup
    MaxPower 100mA
    Interface Association:
      bLength 8
      bDescriptorType 11
      bFirstInterface 0
      bInterfaceCount 2
      bFunctionClass 2 Communications
      bFunctionSubClass 255
      bFunctionProtocol 1
      iFunction 2
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 0
      bAlternateSetting 0
      bNumEndpoints 1
      bInterfaceClass 2 Communications
      bInterfaceSubClass 2 Abstract (modem)
      bInterfaceProtocol 1 AT-commands (v.25ter)
      iInterface 0
      CDC Header:
        bcdCDC 1.10
      CDC Call Management:
        bmCapabilities 0x00
        bDataInterface 1
      UNRECOGNIZED CDC: 04 24 ff 02
      CDC Union:
        bMasterInterface 0
        bSlaveInterface 1
      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 255
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 1
      bAlternateSetting 0
      bNumEndpoints 2
      bInterfaceClass 10 CDC Data
      bInterfaceSubClass 0 Unused
      bInterfaceProtocol 0
      iInterface 0
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x03 EP 3 OUT
        bmAttributes 2
          Transfer Type Bulk
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0040 1x 64 bytes
        bInterval 0
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x81 EP 1 IN
        bmAttributes 2
          Transfer Type Bulk
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0040 1x 64 bytes
        bInterval 0