diff --git a/src/add-ons/kernel/bus_managers/usb/BusManager.cpp b/src/add-ons/kernel/bus_managers/usb/BusManager.cpp
index 4889375989..99f7953866 100644
--- a/src/add-ons/kernel/bus_managers/usb/BusManager.cpp
+++ b/src/add-ons/kernel/bus_managers/usb/BusManager.cpp
@@ -264,6 +264,29 @@ BusManager::Stop()
 }
 
 
+status_t
+BusManager::StartDebugTransfer(Transfer *transfer)
+{
+	// virtual function to be overridden
+	return B_UNSUPPORTED;
+}
+
+
+status_t
+BusManager::CheckDebugTransfer(Transfer *transfer)
+{
+	// virtual function to be overridden
+	return B_UNSUPPORTED;
+}
+
+
+void
+BusManager::CancelDebugTransfer(Transfer *transfer)
+{
+	// virtual function to be overridden
+}
+
+
 status_t
 BusManager::SubmitTransfer(Transfer *transfer)
 {
diff --git a/src/add-ons/kernel/bus_managers/usb/usb.cpp b/src/add-ons/kernel/bus_managers/usb/usb.cpp
index 718b71e73e..4b9da16afd 100644
--- a/src/add-ons/kernel/bus_managers/usb/usb.cpp
+++ b/src/add-ons/kernel/bus_managers/usb/usb.cpp
@@ -17,6 +17,54 @@ Stack *gUSBStack = NULL;
 
 
 #ifdef HAIKU_TARGET_PLATFORM_HAIKU
+/*!	The function is an evil hack to allow <tt> <kdebug>usb_keyboard </tt> to
+	execute transfers.
+	When invoked the first time, a new transfer is started, each time the
+	function is called afterwards, it is checked whether the transfer is already
+	completed. If called with argv[1] == "cancel" the function cancels a
+	possibly pending transfer.
+*/
+static status_t
+debug_run_transfer(Pipe *pipe, uint8 *data, size_t dataLength,
+	usb_request_data *requestData, bool cancel)
+{
+	static uint8 transferBuffer[sizeof(Transfer)]
+		__attribute__((aligned(16)));
+	static Transfer *transfer = NULL;
+
+	BusManager *bus = pipe->GetBusManager();
+
+	if (cancel) {
+		if (transfer != NULL) {
+			bus->CancelDebugTransfer(transfer);
+			transfer = NULL;
+		}
+
+		return B_OK;
+	}
+
+	if (transfer != NULL) {
+		status_t error = bus->CheckDebugTransfer(transfer);
+		if (error != B_DEV_PENDING)
+			transfer = NULL;
+
+		return error;
+	}
+
+	transfer = new(transferBuffer) Transfer(pipe);
+	transfer->SetData(data, dataLength);
+	transfer->SetRequestData(requestData);
+
+	status_t error = bus->StartDebugTransfer(transfer);
+	if (error != B_OK) {
+		transfer = NULL;
+		return error;
+	}
+
+	return B_DEV_PENDING;
+}
+
+
 static int
 debug_get_pipe_for_id(int argc, char **argv)
 {
@@ -34,6 +82,23 @@ debug_get_pipe_for_id(int argc, char **argv)
 	set_debug_variable("_usbPipe", (uint64)object);
 	return 0;
 }
+
+
+static int
+debug_process_transfer(int argc, char **argv)
+{
+	Pipe *pipe = (Pipe *)get_debug_variable("_usbPipe", 0);
+	if (pipe == NULL)
+		return B_BAD_VALUE;
+
+	uint8 *data = (uint8 *)get_debug_variable("_usbTransferData", 0);
+	size_t length = (size_t)get_debug_variable("_usbTransferLength", 0);
+	usb_request_data *requestData
+		= (usb_request_data *)get_debug_variable("_usbRequestData", 0);
+
+	return debug_run_transfer(pipe, data, length, requestData,
+		argc > 1 && strcmp(argv[1], "cancel") == 0);
+}
 #endif
 
 
@@ -83,7 +148,11 @@ bus_std_ops(int32 op, ...)
 #ifdef HAIKU_TARGET_PLATFORM_HAIKU
 			add_debugger_command("get_usb_pipe_for_id",
 				&debug_get_pipe_for_id,
-				"Gets the config for a USB pipe");
+				"Sets _usbPipe by resolving _usbPipeID");
+			add_debugger_command("usb_process_transfer",
+				&debug_process_transfer,
+				"Transfers _usbTransferData with _usbTransferLength"
+				" (and/or _usbRequestData) to pipe _usbPipe");
 #elif HAIKU_TARGET_PLATFORM_BEOS
 			// Plain R5 workaround, see comment above.
 			shared = create_area("shared usb stack", &address,
diff --git a/src/add-ons/kernel/bus_managers/usb/usb_private.h b/src/add-ons/kernel/bus_managers/usb/usb_private.h
index 8ca6b84fe3..2e20979e88 100644
--- a/src/add-ons/kernel/bus_managers/usb/usb_private.h
+++ b/src/add-ons/kernel/bus_managers/usb/usb_private.h
@@ -211,6 +211,10 @@ virtual void							FreeDevice(Device *device);
 virtual	status_t						Start();
 virtual	status_t						Stop();
 
+virtual	status_t						StartDebugTransfer(Transfer *transfer);
+virtual	status_t						CheckDebugTransfer(Transfer *transfer);
+virtual	void							CancelDebugTransfer(Transfer *transfer);
+
 virtual	status_t						SubmitTransfer(Transfer *transfer);
 virtual	status_t						CancelQueuedTransfers(Pipe *pipe,
 											bool force);
@@ -680,6 +684,10 @@ public:
 
 		void						SetCallback(usb_callback_func callback,
 										void *cookie);
+		usb_callback_func			Callback() const
+										{ return fCallback; }
+		void *						CallbackCookie() const
+										{ return fCallbackCookie; }
 
 		void						Finished(uint32 status,
 										size_t actualLength);
diff --git a/src/add-ons/kernel/busses/usb/ehci.cpp b/src/add-ons/kernel/busses/usb/ehci.cpp
index 29cb8d1e0e..dfa51f8448 100644
--- a/src/add-ons/kernel/busses/usb/ehci.cpp
+++ b/src/add-ons/kernel/busses/usb/ehci.cpp
@@ -22,8 +22,6 @@
 pci_module_info *EHCI::sPCIModule = NULL;
 pci_x86_module_info *EHCI::sPCIx86Module = NULL;
 
-static int32 sDebuggerCommandAdded = 0;
-
 
 static int32
 ehci_std_ops(int32 op, ...)
@@ -107,83 +105,6 @@ print_queue(ehci_qh *queueHead)
 #endif // TRACE_USB
 
 
-class DebugTransfer : public Transfer {
-public:
-	DebugTransfer(Pipe *pipe)
-		:
-		Transfer(pipe)
-	{
-	}
-
-	ehci_qh *	queue_head;
-	ehci_qtd *	data_descriptor;
-	bool		direction_in;
-};
-
-
-/*!	The function is an evil hack to allow <tt> <kdebug>usb_keyboard </tt> to
-	execute transfers.
-	When invoked the first time, a new transfer is started, each time the
-	function is called afterwards, it is checked whether the transfer is already
-	completed. If called with argv[1] == "cancel" the function cancels a
-	possibly pending transfer.
-*/
-static int
-debug_process_transfer(int argc, char **argv)
-{
-	Pipe *pipe = (Pipe *)get_debug_variable("_usbPipe", 0);
-	if (pipe == NULL)
-		return 2;
-
-	// check if we have a EHCI bus at all
-	if (pipe->GetBusManager()->TypeName()[0] != 'e')
-		return 3;
-
-	uint8 *data = (uint8 *)get_debug_variable("_usbTransferData", 0);
-	if (data == NULL)
-		return 4;
-
-	size_t length = (size_t)get_debug_variable("_usbTransferLength", 0);
-	if (length == 0)
-		return 5;
-
-	static uint8 transferBuffer[sizeof(DebugTransfer)]
-		__attribute__((aligned(16)));
-	static DebugTransfer *transfer = NULL;
-
-	EHCI *bus = (EHCI *)pipe->GetBusManager();
-
-	if (argc > 1 && strcmp(argv[1], "cancel") == 0) {
-		if (transfer != NULL) {
-			bus->CancelDebugTransfer(transfer);
-			transfer = NULL;
-		}
-
-		return 0;
-	}
-
-	if (transfer != NULL) {
-		bool stillPending;
-		status_t error = bus->CheckDebugTransfer(transfer, stillPending);
-		if (stillPending)
-			return 6;
-
-		transfer = NULL;
-		return error == B_OK ? 0 : 7;
-	}
-
-	transfer = new(transferBuffer) DebugTransfer(pipe);
-	transfer->SetData(data, length);
-
-	if (bus->StartDebugTransfer(transfer) != B_OK) {
-		transfer = NULL;
-		return 7;
-	}
-
-	return 8;
-}
-
-
 //
 // #pragma mark -
 //
@@ -636,12 +557,6 @@ EHCI::EHCI(pci_info *info, Stack *stack)
 	TRACE("set the async list addr to 0x%08" B_PRIx32 "\n",
 		ReadOpReg(EHCI_ASYNCLISTADDR));
 
-	if (atomic_add(&sDebuggerCommandAdded, 1) == 0) {
-		add_debugger_command("ehci_process_transfer",
-			&debug_process_transfer,
-			"Processes a USB transfer with the given variables");
-	}
-
 	fInitOK = true;
 	TRACE("EHCI host controller driver constructed\n");
 }
@@ -651,11 +566,6 @@ EHCI::~EHCI()
 {
 	TRACE("tear down EHCI host controller driver\n");
 
-	if (atomic_add(&sDebuggerCommandAdded, -1) == 1) {
-		remove_debugger_command("ehci_process_transfer",
-			&debug_process_transfer);
-	}
-
 	WriteOpReg(EHCI_USBCMD, 0);
 	WriteOpReg(EHCI_CONFIGFLAG, 0);
 	CancelAllPendingTransfers();
@@ -783,37 +693,41 @@ EHCI::Start()
 
 
 status_t
-EHCI::StartDebugTransfer(DebugTransfer *transfer)
+EHCI::StartDebugTransfer(Transfer *transfer)
 {
-	Pipe *pipe = transfer->TransferPipe();
-	transfer->queue_head = CreateQueueHead();
-	if (transfer->queue_head == NULL)
+	static transfer_data transferData;
+
+	transferData.queue_head = CreateQueueHead();
+	if (transferData.queue_head == NULL)
 		return B_NO_MEMORY;
 
-	status_t result = InitQueueHead(transfer->queue_head, pipe);
+	Pipe *pipe = transfer->TransferPipe();
+	status_t result = InitQueueHead(transferData.queue_head, pipe);
 	if (result != B_OK) {
-		FreeQueueHead(transfer->queue_head);
+		FreeQueueHead(transferData.queue_head);
 		return result;
 	}
 
 	if ((pipe->Type() & USB_OBJECT_CONTROL_PIPE) != 0) {
-		result = FillQueueWithRequest(transfer, transfer->queue_head,
-			&transfer->data_descriptor, &transfer->direction_in);
+		result = FillQueueWithRequest(transfer, transferData.queue_head,
+			&transferData.data_descriptor, &transferData.incoming);
 	} else {
-		result = FillQueueWithData(transfer, transfer->queue_head,
-			&transfer->data_descriptor, &transfer->direction_in);
+		result = FillQueueWithData(transfer, transferData.queue_head,
+			&transferData.data_descriptor, &transferData.incoming);
 	}
 
 	if (result != B_OK) {
-		FreeQueueHead(transfer->queue_head);
+		FreeQueueHead(transferData.queue_head);
 		return result;
 	}
 
 	if ((pipe->Type() & USB_OBJECT_INTERRUPT_PIPE) != 0)
-		LinkPeriodicDebugQueueHead(transfer->queue_head, pipe);
+		LinkPeriodicDebugQueueHead(transferData.queue_head, pipe);
 	else
-		LinkAsyncDebugQueueHead(transfer->queue_head);
+		LinkAsyncDebugQueueHead(transferData.queue_head);
 
+	// we abuse the callback cookie to hold our transfer data
+	transfer->SetCallback(NULL, &transferData);
 	return B_OK;
 }
 
@@ -853,11 +767,12 @@ EHCI::LinkPeriodicDebugQueueHead(ehci_qh *queueHead, Pipe *pipe)
 
 
 status_t
-EHCI::CheckDebugTransfer(DebugTransfer *transfer, bool &_stillPending)
+EHCI::CheckDebugTransfer(Transfer *transfer)
 {
 	bool transferOK = false;
 	bool transferError = false;
-	ehci_qtd *descriptor = transfer->queue_head->element_log;
+	transfer_data *transferData = (transfer_data *)transfer->CallbackCookie();
+	ehci_qtd *descriptor = transferData->queue_head->element_log;
 
 	while (descriptor) {
 		uint32 status = descriptor->token;
@@ -895,36 +810,36 @@ EHCI::CheckDebugTransfer(DebugTransfer *transfer, bool &_stillPending)
 
 	if (!transferOK && !transferError) {
 		spin(75);
-		_stillPending = true;
-		return B_OK;
+		return B_DEV_PENDING;
 	}
 
 	if (transferOK) {
 		bool nextDataToggle = false;
-		if (transfer->data_descriptor != NULL && transfer->direction_in) {
+		if (transferData->data_descriptor != NULL && transferData->incoming) {
 			// data to read out
 			iovec *vector = transfer->Vector();
 			size_t vectorCount = transfer->VectorCount();
 
-			ReadDescriptorChain(transfer->data_descriptor,
+			ReadDescriptorChain(transferData->data_descriptor,
 				vector, vectorCount, &nextDataToggle);
-		} else if (transfer->data_descriptor != NULL)
-			ReadActualLength(transfer->data_descriptor, &nextDataToggle);
+		} else if (transferData->data_descriptor != NULL)
+			ReadActualLength(transferData->data_descriptor, &nextDataToggle);
 
 		transfer->TransferPipe()->SetDataToggle(nextDataToggle);
 	}
 
 	CleanupDebugTransfer(transfer);
-	_stillPending = false;
 	return transferOK ? B_OK : B_IO_ERROR;
 }
 
 
 void
-EHCI::CancelDebugTransfer(DebugTransfer *transfer)
+EHCI::CancelDebugTransfer(Transfer *transfer)
 {
+	transfer_data *transferData = (transfer_data *)transfer->CallbackCookie();
+
 	// clear the active bit so the descriptors are canceled
-	ehci_qtd *descriptor = transfer->queue_head->element_log;
+	ehci_qtd *descriptor = transferData->queue_head->element_log;
 	while (descriptor != NULL) {
 		descriptor->token &= ~EHCI_QTD_STATUS_ACTIVE;
 		descriptor = descriptor->next_log;
@@ -936,9 +851,10 @@ EHCI::CancelDebugTransfer(DebugTransfer *transfer)
 
 
 void
-EHCI::CleanupDebugTransfer(DebugTransfer *transfer)
+EHCI::CleanupDebugTransfer(Transfer *transfer)
 {
-	ehci_qh *queueHead = transfer->queue_head;
+	transfer_data *transferData = (transfer_data *)transfer->CallbackCookie();
+	ehci_qh *queueHead = transferData->queue_head;
 	ehci_qh *prevHead = queueHead->prev_log;
 	if (prevHead != NULL) {
 		prevHead->next_phy = queueHead->next_phy;
diff --git a/src/add-ons/kernel/busses/usb/ehci.h b/src/add-ons/kernel/busses/usb/ehci.h
index 9c22ce6855..0e7aa7a80f 100644
--- a/src/add-ons/kernel/busses/usb/ehci.h
+++ b/src/add-ons/kernel/busses/usb/ehci.h
@@ -16,7 +16,6 @@ struct pci_info;
 struct pci_module_info;
 struct pci_x86_module_info;
 
-class DebugTransfer;
 class EHCIRootHub;
 
 
@@ -57,16 +56,13 @@ public:
 
 		status_t					Start();
 
-		status_t					StartDebugTransfer(DebugTransfer *transfer);
-		status_t					CheckDebugTransfer(DebugTransfer *transfer,
-										bool &_stillPending);
+virtual	status_t					StartDebugTransfer(Transfer *transfer);
+virtual	status_t					CheckDebugTransfer(Transfer *transfer);
 		void						LinkAsyncDebugQueueHead(ehci_qh *queueHead);
 		void						LinkPeriodicDebugQueueHead(
 										ehci_qh *queueHead, Pipe *pipe);
-		void						CancelDebugTransfer(
-										DebugTransfer *transfer);
-		void						CleanupDebugTransfer(
-										DebugTransfer *transfer);
+virtual	void						CancelDebugTransfer(Transfer *transfer);
+		void						CleanupDebugTransfer(Transfer *transfer);
 
 virtual	status_t					SubmitTransfer(Transfer *transfer);
 		status_t					SubmitIsochronous(Transfer *transfer);
diff --git a/src/add-ons/kernel/busses/usb/uhci.cpp b/src/add-ons/kernel/busses/usb/uhci.cpp
index e868d73856..9c93c0e825 100644
--- a/src/add-ons/kernel/busses/usb/uhci.cpp
+++ b/src/add-ons/kernel/busses/usb/uhci.cpp
@@ -21,86 +21,6 @@
 pci_module_info *UHCI::sPCIModule = NULL;
 pci_x86_module_info *UHCI::sPCIx86Module = NULL;
 
-static int32 sDebuggerCommandAdded = 0;
-
-
-#ifdef HAIKU_TARGET_PLATFORM_HAIKU
-
-
-class DebugTransfer : public Transfer {
-public:
-	DebugTransfer(Pipe *pipe)
-		:
-		Transfer(pipe)
-	{
-	}
-
-	uhci_td	*firstDescriptor;
-	uhci_qh	*transferQueue;
-};
-
-
-/*!	The function is an evil hack to allow <tt> <kdebug>usb_keyboard </tt> to
-	execute transfers.
-	When invoked the first time, a new transfer is started, each time the
-	function is called afterwards, it is checked whether the transfer is already
-	completed. If called with argv[1] == "cancel" the function cancels a
-	possibly pending transfer.
-*/
-static int
-debug_process_transfer(int argc, char **argv)
-{
-	Pipe *pipe = (Pipe *)get_debug_variable("_usbPipe", 0);
-	if (pipe == NULL)
-		return 2;
-
-	// check if we have a UHCI bus at all
-	if (pipe->GetBusManager()->TypeName()[0] != 'u')
-		return 3;
-
-	uint8 *data = (uint8 *)get_debug_variable("_usbTransferData", 0);
-	if (data == NULL)
-		return 4;
-
-	size_t length = (size_t)get_debug_variable("_usbTransferLength", 0);
-	if (length == 0)
-		return 5;
-
-	static uint8 transferBuffer[sizeof(DebugTransfer)]
-		__attribute__((aligned(16)));
-	static DebugTransfer* transfer;
-
-	UHCI *bus = (UHCI *)pipe->GetBusManager();
-
-	if (argc > 1 && strcmp(argv[1], "cancel") == 0) {
-		if (transfer != NULL) {
-			bus->CancelDebugTransfer(transfer);
-			transfer = NULL;
-		}
-		return 0;
-	}
-
-	if (transfer != NULL) {
-		bool stillPending;
-		status_t error = bus->CheckDebugTransfer(transfer, stillPending);
-		if (!stillPending)
-			transfer = NULL;
-
-		return error == B_OK ? 0 : 6;
-	}
-
-	transfer = new(transferBuffer) DebugTransfer(pipe);
-	transfer->SetData(data, length);
-
-	if (bus->StartDebugTransfer(transfer) != B_OK) {
-		transfer = NULL;
-		return 7;
-	}
-
-	return 0;
-}
-#endif
-
 
 static int32
 uhci_std_ops(int32 op, ...)
@@ -586,14 +506,6 @@ UHCI::UHCI(pci_info *info, Stack *stack)
 	WriteReg16(UHCI_USBINTR, UHCI_USBINTR_CRC | UHCI_USBINTR_IOC
 		| UHCI_USBINTR_SHORT);
 
-#ifdef HAIKU_TARGET_PLATFORM_HAIKU
-	if (atomic_add(&sDebuggerCommandAdded, 1) == 0) {
-		add_debugger_command("uhci_process_transfer",
-			&debug_process_transfer,
-			"Processes a USB transfer with the given variables");
-	}
-#endif
-
 	TRACE("UHCI host controller driver constructed\n");
 	fInitOK = true;
 }
@@ -601,13 +513,6 @@ UHCI::UHCI(pci_info *info, Stack *stack)
 
 UHCI::~UHCI()
 {
-#ifdef HAIKU_TARGET_PLATFORM_HAIKU
-	if (atomic_add(&sDebuggerCommandAdded, -1) == 1) {
-		remove_debugger_command("uhci_process_transfer",
-			&debug_process_transfer);
-	}
-#endif
-
 	int32 result = 0;
 	fStopThreads = true;
 	delete_sem(fFinishTransfersSem);
@@ -760,27 +665,32 @@ UHCI::SubmitTransfer(Transfer *transfer)
 
 
 status_t
-UHCI::StartDebugTransfer(DebugTransfer *transfer)
+UHCI::StartDebugTransfer(Transfer *transfer)
 {
-	transfer->firstDescriptor = NULL;
-	transfer->transferQueue = NULL;
-	status_t result = CreateFilledTransfer(transfer, &transfer->firstDescriptor,
-		&transfer->transferQueue);
+	static transfer_data transferData;
+	transferData.first_descriptor = NULL;
+	transferData.transfer_queue = NULL;
+	status_t result = CreateFilledTransfer(transfer,
+		&transferData.first_descriptor, &transferData.transfer_queue);
 	if (result < B_OK)
 		return result;
 
-	fQueues[UHCI_DEBUG_QUEUE]->AppendTransfer(transfer->transferQueue, false);
+	fQueues[UHCI_DEBUG_QUEUE]->AppendTransfer(transferData.transfer_queue,
+		false);
 
+	// we abuse the callback cookie to hold our transfer data
+	transfer->SetCallback(NULL, &transferData);
 	return B_OK;
 }
 
 
 status_t
-UHCI::CheckDebugTransfer(DebugTransfer *transfer, bool &_stillPending)
+UHCI::CheckDebugTransfer(Transfer *transfer)
 {
 	bool transferOK = false;
 	bool transferError = false;
-	uhci_td *descriptor = transfer->firstDescriptor;
+	transfer_data *transferData = (transfer_data *)transfer->CallbackCookie();
+	uhci_td *descriptor = transferData->first_descriptor;
 
 	while (descriptor) {
 		uint32 status = descriptor->status;
@@ -804,8 +714,7 @@ UHCI::CheckDebugTransfer(DebugTransfer *transfer, bool &_stillPending)
 
 	if (!transferOK && !transferError) {
 		spin(200);
-		_stillPending = true;
-		return B_OK;
+		return B_DEV_PENDING;
 	}
 
 	if (transferOK) {
@@ -815,29 +724,31 @@ UHCI::CheckDebugTransfer(DebugTransfer *transfer, bool &_stillPending)
 			iovec *vector = transfer->Vector();
 			size_t vectorCount = transfer->VectorCount();
 
-			ReadDescriptorChain(transfer->firstDescriptor,
+			ReadDescriptorChain(transferData->first_descriptor,
 				vector, vectorCount, &lastDataToggle);
 		} else {
 			// read the actual length that was sent
-			ReadActualLength(transfer->firstDescriptor, &lastDataToggle);
+			ReadActualLength(transferData->first_descriptor, &lastDataToggle);
 		}
 
 		transfer->TransferPipe()->SetDataToggle(lastDataToggle == 0);
 	}
 
-	fQueues[UHCI_DEBUG_QUEUE]->RemoveTransfer(transfer->transferQueue, false);
-	FreeDescriptorChain(transfer->firstDescriptor);
-	FreeTransferQueue(transfer->transferQueue);
-	_stillPending = false;
+	fQueues[UHCI_DEBUG_QUEUE]->RemoveTransfer(transferData->transfer_queue,
+		false);
+	FreeDescriptorChain(transferData->first_descriptor);
+	FreeTransferQueue(transferData->transfer_queue);
 	return transferOK ? B_OK : B_IO_ERROR;
 }
 
 
 void
-UHCI::CancelDebugTransfer(DebugTransfer *transfer)
+UHCI::CancelDebugTransfer(Transfer *transfer)
 {
+	transfer_data *transferData = (transfer_data *)transfer->CallbackCookie();
+
 	// clear the active bit so the descriptors are canceled
-	uhci_td *descriptor = transfer->firstDescriptor;
+	uhci_td *descriptor = transferData->first_descriptor;
 	while (descriptor) {
 		descriptor->status &= ~TD_STATUS_ACTIVE;
 		descriptor = (uhci_td *)descriptor->link_log;
@@ -846,9 +757,10 @@ UHCI::CancelDebugTransfer(DebugTransfer *transfer)
 	transfer->Finished(B_CANCELED, 0);
 
 	// dequeue and free resources
-	fQueues[UHCI_DEBUG_QUEUE]->RemoveTransfer(transfer->transferQueue, false);
-	FreeDescriptorChain(transfer->firstDescriptor);
-	FreeTransferQueue(transfer->transferQueue);
+	fQueues[UHCI_DEBUG_QUEUE]->RemoveTransfer(transferData->transfer_queue,
+		false);
+	FreeDescriptorChain(transferData->first_descriptor);
+	FreeTransferQueue(transferData->transfer_queue);
 	// TODO: [bonefish] The Free*() calls cause "PMA: provided address resulted
 	// in invalid index" to be printed, so apparently something is not right.
 	// Though I have not clue what. This is the same cleanup code as in
diff --git a/src/add-ons/kernel/busses/usb/uhci.h b/src/add-ons/kernel/busses/usb/uhci.h
index f5fbb78d8d..d46d4809fb 100644
--- a/src/add-ons/kernel/busses/usb/uhci.h
+++ b/src/add-ons/kernel/busses/usb/uhci.h
@@ -24,8 +24,8 @@
 struct pci_info;
 struct pci_module_info;
 struct pci_x86_module_info;
+
 class UHCIRootHub;
-class DebugTransfer;
 
 
 class Queue {
@@ -99,11 +99,11 @@ public:
 
 		status_t					Start();
 virtual	status_t					SubmitTransfer(Transfer *transfer);
-		status_t					StartDebugTransfer(DebugTransfer *transfer);
-		status_t					CheckDebugTransfer(DebugTransfer *transfer,
-										bool &_stillPending);
-		void						CancelDebugTransfer(
-										DebugTransfer *transfer);
+
+virtual	status_t					StartDebugTransfer(Transfer *transfer);
+virtual	status_t					CheckDebugTransfer(Transfer *transfer);
+virtual	void						CancelDebugTransfer(Transfer *transfer);
+
 virtual	status_t					CancelQueuedTransfers(Pipe *pipe, bool force);
 		status_t					CancelQueuedIsochronousTransfers(Pipe *pipe, bool force);
 		status_t					SubmitRequest(Transfer *transfer);