Comment 2 for bug 1626371

The hub is a OneLink+. The USB CDC device is:

$ sudo lsusb -vv -d 17ef:3054
[sudo] password for joel:
Protocol spec without prior Class and Subclass spec at line 13605

Bus 002 Device 004: ID 17ef:3054 Lenovo
Device Descriptor:
  bLength 18
  bDescriptorType 1
  bcdUSB 3.00
  bDeviceClass 0 (Defined at Interface level)
  bDeviceSubClass 0
  bDeviceProtocol 0
  bMaxPacketSize0 9
  idVendor 0x17ef Lenovo
  idProduct 0x3054
  bcdDevice 30.01
  iManufacturer 1 Lenovo
  iProduct 2 OneLink+ Giga
  iSerial 6 00000E000000
  bNumConfigurations 2
  Configuration Descriptor:
    bLength 9
    bDescriptorType 2
    wTotalLength 57
    bNumInterfaces 1
    bConfigurationValue 1
    iConfiguration 0
    bmAttributes 0xa0
      (Bus Powered)
      Remote Wakeup
    MaxPower 64mA
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 0
      bAlternateSetting 0
      bNumEndpoints 3
      bInterfaceClass 255 Vendor Specific Class
      bInterfaceSubClass 255 Vendor Specific Subclass
      bInterfaceProtocol 0
      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 0x0400 1x 1024 bytes
        bInterval 0
        bMaxBurst 3
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x02 EP 2 OUT
        bmAttributes 2
          Transfer Type Bulk
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0400 1x 1024 bytes
        bInterval 0
        bMaxBurst 3
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x83 EP 3 IN
        bmAttributes 3
          Transfer Type Interrupt
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0002 1x 2 bytes
        bInterval 8
        bMaxBurst 0
  Configuration Descriptor:
    bLength 9
    bDescriptorType 2
    wTotalLength 98
    bNumInterfaces 2
    bConfigurationValue 2
    iConfiguration 0
    bmAttributes 0xa0
      (Bus Powered)
      Remote Wakeup
    MaxPower 64mA
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 0
      bAlternateSetting 0
      bNumEndpoints 1
      bInterfaceClass 2 Communications
      bInterfaceSubClass 6 Ethernet Networking
      bInterfaceProtocol 0
      iInterface 5 CDC Communications Control
      CDC Header:
        bcdCDC 1.10
      CDC Union:
        bMasterInterface 0
        bSlaveInterface 1
      CDC Ethernet:
        iMacAddress 3 0050B6D331FE
        bmEthernetStatistics 0x00000000
        wMaxSegmentSize 1514
        wNumberMCFilters 0x0000
        bNumberPowerFilters 0
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x83 EP 3 IN
        bmAttributes 3
          Transfer Type Interrupt
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0010 1x 16 bytes
        bInterval 8
        bMaxBurst 0
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 1
      bAlternateSetting 0
      bNumEndpoints 0
      bInterfaceClass 10 CDC Data
      bInterfaceSubClass 0 Unused
      bInterfaceProtocol 0
      iInterface 0
    Interface Descriptor:
      bLength 9
      bDescriptorType 4
      bInterfaceNumber 1
      bAlternateSetting 1
      bNumEndpoints 2
      bInterfaceClass 10 CDC Data
      bInterfaceSubClass 0 Unused
      bInterfaceProtocol 0
      iInterface 4 Ethernet Data
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x81 EP 1 IN
        bmAttributes 2
          Transfer Type Bulk
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0400 1x 1024 bytes
        bInterval 0
        bMaxBurst 3
      Endpoint Descriptor:
        bLength 7
        bDescriptorType 5
        bEndpointAddress 0x02 EP 2 OUT
        bmAttributes 2
          Transfer Type Bulk
          Synch Type None
          Usage Type Data
        wMaxPacketSize 0x0400 1x 1024 bytes
        bInterval 0
        bMaxBurst 3
Binary Object Store Descriptor:
  bLength 5
  bDescriptorType 15
  wTotalLength 22
  bNumDeviceCaps 2
  USB 2.0 Extension Device Capability:
    bLength 7
    bDescriptorType 16
    bDevCapabilityType 2
    bmAttributes 0x00000002
      Link Power Management (LPM) Supported
  SuperSpeed USB Device Capability:
    bLength 10
    bDescriptorType 16
    bDevCapabilityType 3
    bmAttributes 0x02
      Latency Tolerance Messages (LTM) Supported
    wSpeedsSupported 0x000e
      Device can operate at Full Speed (12Mbps)
      Device can operate at High Speed (480Mbps)
      Device can operate at SuperSpeed (5Gbps)
    bFunctionalitySupport 2
      Lowest fully-functional device speed is High Speed (480Mbps)
    bU1DevExitLat 10 micro seconds
    bU2DevExitLat 2047 micro seconds
Device Status: 0x0018
  (Bus Powered)
  U2 Enabled
  Latency Tolerance Messaging (LTM) Enabled