Keep the role vocabularies separate
| Function | Origin role | Destination role |
|---|---|---|
| Power | Source | Sink |
| USB data | Host / DFP | Device / UFP |
| Display | Video source | Video sink |
Dual-role products can swap some roles through USB Power Delivery policy. Do not infer that behavior from the receptacle. Two computers with USB-C ports, for example, are not automatically a useful USB data connection because both may expect the host role.
Plan a one-cable monitor in four passes
- Confirm that the exact host port outputs video and the monitor’s exact USB-C port accepts video.
- Use a cable that explicitly supports the required video path and charging current.
- Compare the exact display payload with the usable link capacity, including lane sharing or DSC.
- Separately compare monitor PD output with the laptop target and monitor-hub traffic with its USB upstream pool.
Do not turn “works” into “full-featured.”
A monitor may display video but charge slowly, or it may charge while its downstream USB hub uses a reduced data path.
A monitor may display video but charge slowly, or it may charge while its downstream USB hub uses a reduced data path.
Sources
- USB-IF: USB Type-C System OverviewPower roles, data roles, and USB PD role swaps.
- Microsoft Support: Fix USB-C problems in WindowsWrong ports, cables, intermediaries, and power limitations.