The !usbkd.usbtx command displays information from a usbport!_HCD_TRANSFER_CONTEXT structure.

!usbkd.usbtx StructAddr


Address of a usbport!_HCD_TRANSFER_CONTEXT structure. To get the transfer list for a USB host controller, use the !usbkd.usbhcdext command.




Here is one way to find the address of a usbport!_HCD_TRANSFER_CONTEXT structure. First enter !usbkd.usb2tree.

0: kd> !usbkd.usb2tree
4)!uhci_info ffffe00001c8f1a0 !devobj ffffe00001c8f050 PCI: VendorId 8086 DeviceId 2938 RevisionId 0002 

In the preceding output, the address of the device extension of the FDO is displayed as the argument of the DML command !uhci_info ffffe00001c8f1a0.

Either click the DML command or pass the address of the device extension to !usbhcdext to get the transfer list.

0: kd> !usbkd.usbhcdext ffffe00001c8f1a0

1.) Transfer Request Priority List: (TxQueued) Type: 0-NotSplit, 1-Parent, 2-Child
    [000]!usbtx ffffe0000653401c !usbep ffffe00004730c60 !irp ffffe00004221220 State: (7)TX_Mapped_inMp
        Priority: 0, Type: 0, Flags= 0000000a, SequenceNum: 10, SplitIdx: 0
        InLen: 4096, OutLen: 0 Status: USBD_STATUS_PENDING (0x40000000)

In the preceding output, ffffe0000653401c is the address of an _HCD_TRANSFER_CONTEXTstructure. Pass this address to !usbtx.

0: kd> !usbkd.usbtx ffffe0000653401c

dt usbport!_HCD_TRANSFER_CONTEXT ffffe0000653401c
dt usbport!_TRANSFER_PARAMETERS ffffe0000653417c


## EVENT, STATE, NEXT (latest at bottom)

[01]    (23)Ev_TX_Icsq, (0)TX_Undefined, (1)TX_InQueue
[02]    (5)Ev_TX_MapTransfer, (1)TX_InQueue, (2)TX_MapPending
[03]    (7)Ev_TX_MpSubmitSuccess, (2)TX_MapPending, (7)TX_Mapped_inMp

dt usbport!_TRANSFER_SG_LIST ffffe0000653439c
SgCount:  1  MdlVirtualAddress: ffffe00000437000  MdlSystemAddress: ffffe00000437000
    [0] dt usbport!_TRANSFER_SG_ENTRY ffffe000065343bc
    : sysaddr: 0000000000000000 len 0x00001000(4096) offset 0x00000000(0) phys 00000000'ded90000
dt usbport!_SCATTER_GATHER_ENTRY ffffe000065343ec
dt _SCATTER_GATHER_LIST ffffe00001bc231c
NumberOfElements = 1
    [0] dt _SCATTER_GATHER_ELEMENT ffffe00001bc232c
     :phys 00000000'ded90000 len 0x00001000(4096)

See also

USB 2.0 Debugger Extensions

Universal Serial Bus (USB) Drivers