SuperSpeed device emulation with EC3380-AB doesn't work

[xairy]

Device:

$ sudo ./keyboard 
event: connect, length: 0
event: control, length: 8
  bRequestType: 0x80 (IN), bRequest: 0x6, wValue: 0x100, wIndex: 0x0, wLength: 8
  type = USB_TYPE_STANDARD
  req = USB_REQ_GET_DESCRIPTOR
  descriptor = USB_DT_DEVICE
ioctl(USB_RAW_IOCTL_EP0_WRITE): Protocol error

Host:

Apr  9 19:03:57 host kernel: [ 2858.561124] usb 4-2.4.4: new SuperSpeed USB device number 7 using xhci_hcd
Apr  9 19:04:02 host kernel: [ 2863.596761] usb 4-2.4.4: device descriptor read/8, error -110
Apr  9 19:04:03 host kernel: [ 2863.704532] usb 4-2.4.4: new SuperSpeed USB device number 7 using xhci_hcd

[xairy]

Looks like that device barely works even without USB 3 as the net2280 UDC driver is buggy. Don't see any point in tracking this, let's declare that device "not supported".