USB4 Systems DisplayPort Alternate Mode Support

  • Article

Verifies that systems support DisplayPort alternate mode on all exposed USB4 ports.

Description

Systems that incorporate a USB4 host router and support external user connectable USB4 port(s) must support DisplayPort (DP) Alternate Mode on all exposed USB4 connectors in accordance with the Power Deliver Specification and the VESA specification for DisplayPort Alternate Mode on USB Type-C connector standard.

A broad ecosystem of USB Type-C DP Alternate Mode compatible hosts and peripherals exists today, and DP dongles are becoming ubiquitous as USB Type-C quickly replaces legacy display connections on mobile computing devices. Users will expect these peripherals to continue to work with their new USB4 enabled systems and will not appreciate the difference between a DP tunnel and DP Alternate Mode if USB4 hosts do not inter-operate with them. With the goal of maximizing compatibility with the existing ecosystem of USB Type-C DisplayPort Alternate Mode peripherals, all systems supporting USB4 must support DisplayPort Alternate Mode on all exposed USB4 connectors.

Test details

   
Specifications
  • System.Fundamentals.SystemUSB.USB4.SupportDisplayPortAlternateMode
Platforms
  • Windows 10, client editions (x86)
  • Windows 10, client editions (x64)
  • Windows 10, client editions (Arm)
  • Windows 10, client editions (Arm64)
Supported Releases
  • Windows 11
  • Next update to Windows 11
Expected run time (in minutes) 5
Category Development and Integration
Timeout (in minutes) 5
Requires reboot False
Requires special configuration False
Type development

Additional documentation

Tests in this feature area might have additional documentation, including prerequisites, setup, and troubleshooting information, that can be found in the following topic:

More information

Parameters

None

Enhancement scenarios

USB Type-C DisplayPort alternate mode dongles continue to work with USB4 hosts.

Implementation Notes

  • It's expected that the most feasible method to implement DP Alternate Mode on a USB4 port is in the USB4 host router silicon, although it may also be achievable by other means.
  • Each USB4 port must support DisplayPort alternate mode, but they need not all operate simultaneously. If, for example, the host system's GPU supports fewer display outputs than there are USB4 ports, the display streams may only be available on a first-come, first-serve basis.

Troubleshooting

For generic troubleshooting of HLK test failures, see Troubleshooting Windows HLK Test Failures.