For drag-n-drop events moving from source display (S) to target display (T), all events (mouse press, mouse drag * N, mouse release) are relative to S (uses S's display_id and event location is relative to S's position). This is because we would have a capture after the first mouse press and ozone drm honors capture first. In cash, ash would later do the conversion to send events to the correct display. In mash/mus, window server would do the conversion.

Ideally both ash and WS wouldn't need to do the conversion and ozone drm would take care of finding the right display the cursor is on for drag-n-drop events just like other normal mouse events.