The !usb3kd.xhci_capability extension displays the capabilities of a USB 3.0 host controller.

!usb3kd.xhci_capability DeviceExtension


Address of the device extension for the host controller's functional device object (FDO).




The output the !xhci_capability command is based on the data structures maintained by the USB 3.0 host controller driver (UsbXhci.sys). For more information about the USB 3.0 host controller driver and other drivers in the USB stack, see USB Driver Stack Architecture.


To obtain the address of the device extension, look at the output of the !xhci_dumpall command. In the following example, the address of the device extension is 0xfffffa800536e2d0.

3: kd> !xhci_dumpall

## Dumping all the XHCI controllers - DrvObj 0xfffffa80053072f0
1)  ... - PCI: VendorId ... DeviceId ... RevisionId ... Firmware ...

    dt USBXHCI!_CONTROLLER_DATA 0xfffffa80052f20c0
    !rcdrlogdump USBXHCI -a 0xfffffa8005068520
    !rcdrlogdump USBXHCI -a 0xfffffa8004e8b9a0 (rundown)
    !wdfdevice 0x57ffac91fd8
    !xhci_capability 0xfffffa800536e2d0

Now you can pass the address of the device extension to the !xhci_capability command.

3: kd> !xhci_capability 0xfffffa800536e2d0

## Controller Capabilities
    dt USBXHCI!_REGISTER_DATA 0xfffffa8005362c00
    dt USBXHCI!_CAPABILITY_REGISTERS 0xfffff880046a8000
    MajorRevision.MinorRevision = 0.96
    Device Slots: 32
    Interrupters: 8
    Ports: 4
    IsochSchedulingThreshold: 1
    EventRingSegmentTableMax: 1 (2^ERST = 2)
    ScratchpadRestore: OFF
    MaxScratchpadBuffers: 0
    U1DeviceExitLatency: 0
    U2DeviceExitLatency: 0
    AddressingCapability: 64 bit
    BwNegotiationCapability: ON
    ContextSize: 32 bytes
    PortPowerControl: ON
    PortIndicators: OFF
    LightHCResetCapability: OFF
    LatencyToleranceMessagingCapability: ON
    NoSecondarySidSupport: TRUE
    MaximumPrimaryStreamArraySize = 4 ( 2^(MaxPSASize+1) = 32 )
        [1] USB_LEGACY_SUPPORT: dt _USBLEGSUP 0xfffff880046a8500
        [2] Supported Protocol 0xfffff880046a8510, Version 3.0, Offset 1, Count 2, HighSpeedOnly OFF, IntegratedHub OFF, HardwareLPM OFF
        [3] Supported Protocol 0xfffff880046a8520, Version 2.0, Offset 3, Count 2, HighSpeedOnly OFF, IntegratedHub OFF, HardwareLPM OFF

## Software Supported Capabilities
    DeviceSlots: 32
    Interrupters: 1
    Ports: 4
    MaxEventRingSegments: 2
    U1DeviceExitLatency: 0
    U2DeviceExitLatency: 0

See also

USB 3.0 Extensions


Universal Serial Bus (USB) Drivers

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