wake from suspend from usb keyboard stops working after unplugging/replugging keyboard

When a USB port with attached LS keyboard is in SUSPEND, the bus is in idle LS state, D- is high, no activity. To wake up, the system expects the wake-up signaling sequence - "K-state" should be generated by keyboard (in LS mode the K-state is D+ = high, opposite to FS/HS bus states).

When you unplug the keyboard while in suspend state, the port hardware logic will sense "USB disconnect" (SE0 state), and the port will move into "disabled" state. This will cancel the wake-up mode.

To make the computer to wake up in this situation, you need to enable something like "wake-up on hot plug". I am not sure if this function is available.