I also get this issue. E.g., from kern.log:

May 27 21:15:14 MacKubuntu kernel: [ 3003.296119] usb 3-1: reset full speed USB device using uhci_hcd and address 4                                           
May 27 21:15:14 MacKubuntu kernel: [ 3003.360168] pm_op(): usb_dev_resume+0x0/0x10 returns -19                                                                
May 27 21:15:14 MacKubuntu kernel: [ 3003.360171] PM: Device 3-1 failed to resume: error -19                                                                  
May 27 21:15:14 MacKubuntu kernel: [ 3003.360410] PM: resume devices took 4.260 seconds                                                                       
May 27 21:15:14 MacKubuntu kernel: [ 3003.361146] PM: Finishing wakeup.        
May 27 21:15:14 MacKubuntu kernel: [ 3003.361147] Restarting tasks ... done.   
May 27 21:15:14 MacKubuntu kernel: [ 3003.688140] usb 3-1: USB disconnect, address 4                                                                          
May 27 21:15:14 MacKubuntu kernel: [ 3003.928109] usb 3-1: new full speed USB device using uhci_hcd and address 5                                             
May 27 21:15:14 MacKubuntu kernel: [ 3004.113609] usb 3-1: configuration #1 chosen from 1 choice                                 

If I do lsusb -v I see that usb 3-1 is:

Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub
Device Descriptor:                                            
  bLength                18                                   
  bDescriptorType         1                                   
  bcdUSB               1.10                                   
  bDeviceClass            9 Hub                               
  bDeviceSubClass         0 Unused                            
  bDeviceProtocol         0 Full speed (or root) hub          
  bMaxPacketSize0        64                                   
  idVendor           0x1d6b Linux Foundation                  
  idProduct          0x0001 1.1 root hub                      
  bcdDevice            2.06                                   
  iManufacturer           3                                   
  iProduct                2                                   
  iSerial                 1                                   
  bNumConfigurations      1                                   
  Configuration Descriptor:                                   
    bLength                 9                                 
    bDescriptorType         2                                 
    wTotalLength           25                                 
    bNumInterfaces          1                                 
    bConfigurationValue     1                                 
    iConfiguration          0                                 
    bmAttributes         0xe0                                 
      Self Powered                                            
      Remote Wakeup                                           
    MaxPower                0mA                               
    Interface Descriptor:                                     
      bLength                 9                               
      bDescriptorType         4                               
      bInterfaceNumber        0
      bAlternateSetting       0
      bNumEndpoints           1
      bInterfaceClass         9 Hub
      bInterfaceSubClass      0 Unused
      bInterfaceProtocol      0 Full speed (or root) hub
      iInterface              0
      Endpoint Descriptor:
        bLength                 7
        bDescriptorType         5
        bEndpointAddress     0x81  EP 1 IN
        bmAttributes            3
          Transfer Type            Interrupt
          Synch Type               None
          Usage Type               Data
        wMaxPacketSize     0x0002  1x 2 bytes
        bInterval             255
can't get hub descriptor: Operation not permitted
cannot read device status, Operation not permitted (1)

So it looks like it's some sort of internal hub (I don't have any sort of external hub attached - this is on a Macbook Pro)

I hope this might be of some help.