USB4 Host Router Systems in ACPI Describe Unique IDs

Verifies that systems with USB4 host routers described in ACPI, assign unique numerical identifiers.

Description

Systems with ACPI-described USB4 host routers must set the last character of each device's ACPI name to a numeric digit in the range 0-7 (inclusive) that is unique across all USB4 host routers integrated into the system.

Per ECN: 11241 to the USB4 specification, the USB4 configuration manager (CM) uses a 4-bit field in the DPCD register to communicate to the GPU which USB4 host router instance is tunneling the DisplayPort stream. The graphics driver will retrieve this identifier via the GPU and use it to locate and establish a relationship with the USB4 configuration manager, to coordinate power management.

Test details

Specifications	System.Fundamentals.SystemUSB.USB4.HostRouterACPINames
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:

• System.Fundamentals additional documentation

More information

Parameters

None

Enhancement scenarios

Uniquely identify ACPI-described USB4 Host Routers so they can be associated with dynamically assigned DP targets on the GPU.

Troubleshooting

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