diff --git a/headers/os/drivers/USB3.h b/headers/os/drivers/USB3.h
index 55b84e0b55..7e0d196c15 100644
--- a/headers/os/drivers/USB3.h
+++ b/headers/os/drivers/USB3.h
@@ -74,11 +74,14 @@ struct usb_configuration_info {
 };
 
 typedef struct {
-	int16						req_len;
-	int16						act_len;
+	int16						request_length;
+	int16						actual_length;
 	status_t					status;
 } usb_iso_packet_descriptor;
 
+// Flags for queue_isochronous
+#define	USB_ISO_ASAP	0x01
+
 typedef void (*usb_callback_func)(void *cookie, status_t status, void *data,
 	size_t actualLength);
 
diff --git a/src/add-ons/kernel/bus_managers/usb/Pipe.cpp b/src/add-ons/kernel/bus_managers/usb/Pipe.cpp
index 443025bb48..1f7471dfff 100644
--- a/src/add-ons/kernel/bus_managers/usb/Pipe.cpp
+++ b/src/add-ons/kernel/bus_managers/usb/Pipe.cpp
@@ -198,7 +198,32 @@ IsochronousPipe::QueueIsochronous(void *data, size_t dataLength,
 	uint32 *startingFrameNumber, uint32 flags, usb_callback_func callback,
 	void *callbackCookie)
 {
-	return B_ERROR;
+	// TODO: Check if values of input parameters are set correctely
+	usb_isochronous_data *isochronousData
+		= new(std::nothrow) usb_isochronous_data;
+
+	if (!isochronousData)
+		return B_NO_MEMORY;
+
+	isochronousData->packet_descriptors = packetDesc;
+	isochronousData->packet_count = packetCount;
+	isochronousData->starting_frame_number = startingFrameNumber;
+	isochronousData->flags = flags;
+
+	Transfer *transfer = new(std::nothrow) Transfer(this);
+	if (!transfer) {
+		delete isochronousData;
+		return B_NO_MEMORY;
+	}
+
+	transfer->SetData((uint8 *)data, dataLength);
+	transfer->SetCallback(callback, callbackCookie);
+	transfer->SetIsochronousData(isochronousData);
+
+	status_t result = GetBusManager()->SubmitTransfer(transfer);
+	if (result < B_OK)
+		delete transfer;
+	return result;
 }
 
 
@@ -259,7 +284,9 @@ ControlPipe::SendRequest(uint8 requestType, uint8 request, uint16 value,
 	uint16 index, uint16 length, void *data, size_t dataLength,
 	size_t *actualLength)
 {
-	transfer_result_data *transferResult = (transfer_result_data *)malloc(sizeof(transfer_result_data));
+	transfer_result_data *transferResult
+		= new(std::nothrow) transfer_result_data;
+
 	transferResult->notify_sem = create_sem(0, "usb send request notify");
 	if (transferResult->notify_sem < B_OK)
 		return B_NO_MORE_SEMS;
@@ -290,7 +317,7 @@ ControlPipe::SendRequest(uint8 requestType, uint8 request, uint16 value,
 		*actualLength = transferResult->actual_length;
 
 	result = transferResult->status;
-	free(transferResult);
+	delete transferResult;
 	return result;
 }
 
@@ -304,7 +331,7 @@ ControlPipe::SendRequestCallback(void *cookie, status_t status, void *data,
 	transferResult->actual_length = actualLength;
 	if (release_sem(transferResult->notify_sem) < B_OK) {
 		// the request has timed out already - cleanup after us
-		free(transferResult);
+		delete transferResult;
 	}
 }
 
diff --git a/src/add-ons/kernel/bus_managers/usb/Transfer.cpp b/src/add-ons/kernel/bus_managers/usb/Transfer.cpp
index 6989f96d02..9788349304 100644
--- a/src/add-ons/kernel/bus_managers/usb/Transfer.cpp
+++ b/src/add-ons/kernel/bus_managers/usb/Transfer.cpp
@@ -6,7 +6,6 @@
  *		Michael Lotz <mmlr@mlotz.ch>
  *		Niels S. Reedijk
  */
-
 #include "usb_p.h"
 
 
@@ -21,7 +20,9 @@ Transfer::Transfer(Pipe *pipe)
 		fClonedArea(-1),
 		fCallback(NULL),
 		fCallbackCookie(NULL),
-		fRequestData(NULL)
+		fRequestData(NULL),
+		fIsochronousData(NULL),
+		fBandwidth(0)
 {
 }
 
@@ -47,6 +48,13 @@ Transfer::SetRequestData(usb_request_data *data)
 }
 
 
+void
+Transfer::SetIsochronousData(usb_isochronous_data *data)
+{
+	fIsochronousData = data;
+}
+
+
 void
 Transfer::SetData(uint8 *data, size_t dataLength)
 {
@@ -56,6 +64,12 @@ Transfer::SetData(uint8 *data, size_t dataLength)
 
 	if (data && dataLength > 0)
 		fVectorCount = 1;
+
+	// Calculate the bandwidth (only if it is not a bulk transfer)
+	if (!(fPipe->Type() & USB_OBJECT_BULK_PIPE)) {
+		if (_CalculateBandwidth() < B_OK)
+			TRACE_ERROR(("USB Transfer: can't calculate bandwidth\n"));
+	}
 }
 
 
@@ -187,3 +201,75 @@ Transfer::Finished(uint32 status, size_t actualLength)
 		fCallback(fCallbackCookie, status, fBaseAddress,
 			fActualLength + actualLength);
 }
+
+
+/*
+ * USB 2.0 Spec function, pag 64.
+ * This function sets fBandwidth in microsecond
+ * to the bandwidth needed to transfer fData.iov_len bytes.
+ * The calculation is based on
+ * 1. Speed of the transfer
+ * 2. Pipe direction
+ * 3. Type of pipe
+ * 4. Number of bytes to transfer
+ */
+status_t
+Transfer::_CalculateBandwidth()
+{
+	uint16 bandwidthNS;
+	uint32 type = fPipe->Type();
+
+	switch (fPipe->Speed()) {
+		case USB_SPEED_HIGHSPEED:
+		{
+			// Direction doesn't matter for highspeed
+			if (type & USB_OBJECT_ISO_PIPE)
+				bandwidthNS = (uint16)((38 * 8 * 2.083)
+					+ (2.083 * ((uint32)(3.167 * (1.1667 * 8 * fData.iov_len))))
+					+ USB_BW_HOST_DELAY);
+			else
+				bandwidthNS = (uint16)((55 * 8 * 2.083)
+					+ (2.083 * ((uint32)(3.167 * (1.1667 * 8 * fData.iov_len))))
+					+ USB_BW_HOST_DELAY);
+			break;
+		}
+		case USB_SPEED_FULLSPEED:
+		{
+			// Direction does matter this time for isochronous
+			if (type & USB_OBJECT_ISO_PIPE)
+				bandwidthNS = (uint16)
+					(((fPipe->Direction() == Pipe::In) ? 7268 : 6265)
+					+ (83.54 * ((uint32)(3.167 + (1.1667 * 8 * fData.iov_len))))
+					+ USB_BW_HOST_DELAY);
+			else
+				bandwidthNS = (uint16)(9107
+					+ (83.54 * ((uint32)(3.167 + (1.1667 * 8 * fData.iov_len))))
+					+ USB_BW_HOST_DELAY);
+			break;
+		}
+		case USB_SPEED_LOWSPEED:
+		{
+			if (fPipe->Direction() == Pipe::In)
+				bandwidthNS = (uint16) (64060 + (2 * USB_BW_SETUP_LOW_SPEED_PORT_DELAY)
+					+ (676.67 * ((uint32)(3.167 + (1.1667 * 8 * fData.iov_len))))
+					+ USB_BW_HOST_DELAY);
+			else
+				bandwidthNS = (uint16)(64107 + (2 * USB_BW_SETUP_LOW_SPEED_PORT_DELAY)
+					+ (667.0 * ((uint32)(3.167 + (1.1667 * 8 * fData.iov_len))))
+					+ USB_BW_HOST_DELAY);
+			break;
+		}
+
+		default:
+			// We should never get here
+			TRACE(("USB Transfer: speed unknown"));
+			return B_ERROR;
+	}
+
+	// Round up and set the value in microseconds
+	fBandwidth = (bandwidthNS + 500) / 1000;
+
+	// For debugging purposes
+	TRACE(("USB Transfer: bandwidth neded %d\n", fBandwidth));
+	return B_OK;
+}
diff --git a/src/add-ons/kernel/bus_managers/usb/usb_p.h b/src/add-ons/kernel/bus_managers/usb/usb_p.h
index 53620226d3..d6806f6494 100644
--- a/src/add-ons/kernel/bus_managers/usb/usb_p.h
+++ b/src/add-ons/kernel/bus_managers/usb/usb_p.h
@@ -85,7 +85,6 @@ typedef enum {
 #define USB_OBJECT_DEVICE				0x00000040
 #define USB_OBJECT_HUB					0x00000080
 
-#define USB_MAX_FRAGMENT_SIZE			B_PAGE_SIZE * 96
 
 class Stack {
 public:
@@ -521,6 +520,9 @@ public:
 		void						SetRequestData(usb_request_data *data);
 		usb_request_data			*RequestData() { return fRequestData; };
 
+		void						SetIsochronousData(usb_isochronous_data *data);
+		usb_isochronous_data		*IsochronousData() { return fIsochronousData; };
+
 		void						SetData(uint8 *buffer, size_t length);
 		uint8						*Data() { return (uint8 *)fData.iov_base; };
 		size_t						DataLength() { return fData.iov_len; };
@@ -530,6 +532,8 @@ public:
 		size_t						VectorCount() { return fVectorCount; };
 		size_t						VectorLength();
 
+		uint16						Bandwidth() { return fBandwidth; };
+
 		bool						IsFragmented() { return fFragmented; };
 		void						AdvanceByFragment(size_t actualLength);
 
@@ -542,6 +546,8 @@ public:
 		void						Finished(uint32 status, size_t actualLength);
 
 private:
+		status_t					_CalculateBandwidth();
+
 		// Data that is related to the transfer
 		Pipe						*fPipe;
 		iovec						fData;
@@ -558,6 +564,15 @@ private:
 
 		// For control transfers
 		usb_request_data			*fRequestData;
+
+		// For isochronous transfers
+		usb_isochronous_data		*fIsochronousData;
+
+		// For bandwidth management.
+		// It contains the bandwidth necessary in microseconds
+		// for either isochronous, interrupt or control transfers.
+		// Not used for bulk transactions.
+		uint16						fBandwidth;
 };
 
 #endif
diff --git a/src/add-ons/kernel/bus_managers/usb/usbspec_p.h b/src/add-ons/kernel/bus_managers/usb/usbspec_p.h
index 4945b3745e..04e42610e8 100644
--- a/src/add-ons/kernel/bus_managers/usb/usbspec_p.h
+++ b/src/add-ons/kernel/bus_managers/usb/usbspec_p.h
@@ -16,6 +16,7 @@
 #include <util/kernel_cpp.h>
 
 #define USB_MAX_AREAS					8
+#define USB_MAX_FRAGMENT_SIZE			B_PAGE_SIZE * 96
 
 #define USB_DELAY_BUS_RESET				100000
 #define USB_DELAY_DEVICE_POWER_UP		300000
@@ -28,6 +29,11 @@
 #define USB_DELAY_FIRST_EXPLORE			5000000
 #define USB_DELAY_HUB_EXPLORE			1000000
 
+// For bandwidth calculation
+#define	USB_BW_HOST_DELAY					1000
+#define	USB_BW_SETUP_LOW_SPEED_PORT_DELAY	333
+
+
 /*
 	Important data from the USB spec (not interesting for drivers)
 */
@@ -49,6 +55,14 @@ struct usb_request_data
 };
 
 
+struct usb_isochronous_data {
+	usb_iso_packet_descriptor *packet_descriptors;
+	uint32 packet_count;
+	uint32 *starting_frame_number;
+	uint32 flags;
+};
+
+
 struct usb_hub_descriptor
 {
 	uint8 length;
diff --git a/src/add-ons/kernel/busses/usb/uhci.cpp b/src/add-ons/kernel/busses/usb/uhci.cpp
index e8b7366d71..5186cb8d49 100644
--- a/src/add-ons/kernel/busses/usb/uhci.cpp
+++ b/src/add-ons/kernel/busses/usb/uhci.cpp
@@ -5,6 +5,7 @@
  * Authors:
  *		Michael Lotz <mmlr@mlotz.ch>
  *		Niels S. Reedijk
+ *		Salvatore Benedetto <salvatore.benedetto@gmail.com>
  */
 
 #include <module.h>
@@ -296,11 +297,15 @@ UHCI::UHCI(pci_info *info, Stack *stack)
 		fFrameArea(-1),
 		fFrameList(NULL),
 		fQueueCount(0),
-		fQueues(NULL),	
+		fQueues(NULL),
 		fFirstTransfer(NULL),
 		fLastTransfer(NULL),
 		fFinishThread(-1),
 		fStopFinishThread(false),
+		fFirstIsochronousTransfer(NULL),
+		fLastIsochronousTransfer(NULL),
+		fFinishIsochronousThread(-1),
+		fStopFinishIsochronousThread(false),
 		fRootHub(NULL),
 		fRootHubAddress(0),
 		fPortResetChange(0)
@@ -391,7 +396,7 @@ UHCI::UHCI(pci_info *info, Stack *stack)
 	fQueues[fQueueCount - 1]->TerminateByStrayDescriptor();
 
 	// Create the array that will keep bandwidth information
-	fFrameBandwidth = new(std::nothrow) int32[NUMBER_OF_FRAMES];
+	fFrameBandwidth = new(std::nothrow) uint16[NUMBER_OF_FRAMES];
 
 	for (int32 i = 0; i < NUMBER_OF_FRAMES; i++) {
 		fFrameList[i] =	fQueues[UHCI_INTERRUPT_QUEUE]->PhysicalAddress()
@@ -399,6 +404,10 @@ UHCI::UHCI(pci_info *info, Stack *stack)
 		fFrameBandwidth[i] = MAX_AVAILABLE_BANDWIDTH;
 	}
 
+	// create lists for managing isochronous transfer descriptors
+	fFirstIsochronousDescriptor = new(std::nothrow) uhci_td *[NUMBER_OF_FRAMES];
+	fLastIsochronousDescriptor = new(std::nothrow) uhci_td *[NUMBER_OF_FRAMES];
+
 	// create semaphore the finisher thread will wait for
 	fFinishTransfersSem = create_sem(0, "UHCI Finish Transfers");
 	if (fFinishTransfersSem < B_OK) {
@@ -411,6 +420,18 @@ UHCI::UHCI(pci_info *info, Stack *stack)
 		"uhci finish thread", B_URGENT_DISPLAY_PRIORITY, (void *)this);
 	resume_thread(fFinishThread);
 
+	// Create a lock for the isochronous transfer list
+	if (benaphore_init(&fIsochronousLock, "UHCI isochronous lock") < B_OK) {
+		TRACE_ERROR(("usb_uhci: failed to create isochronous lock\n"));
+		return;
+	}
+
+	// Create the isochronous finisher service thread
+	fFinishIsochronousThread = spawn_kernel_thread(FinishIsochronousThread,
+		"uhci isochronous finish thread", B_URGENT_DISPLAY_PRIORITY,
+		(void *)this);
+	resume_thread(fFinishIsochronousThread);
+
 	// Install the interrupt handler
 	TRACE(("usb_uhci: installing interrupt handler\n"));
 	install_io_interrupt_handler(fPCIInfo->u.h0.interrupt_line,
@@ -429,8 +450,19 @@ UHCI::~UHCI()
 {
 	int32 result = 0;
 	fStopFinishThread = true;
+	fStopFinishIsochronousThread = true;
 	delete_sem(fFinishTransfersSem);
 	wait_for_thread(fFinishThread, &result);
+	wait_for_thread(fFinishIsochronousThread, &result);
+
+	LockIsochronous();
+	isochronous_transfer_data *isoTransfer = fFirstIsochronousTransfer;
+	while (isoTransfer) {
+		isochronous_transfer_data *next = isoTransfer->link;
+		delete isoTransfer;
+		isoTransfer = next;
+	}
+	benaphore_destroy(&fIsochronousLock);
 
 	Lock();
 	transfer_data *transfer = fFirstTransfer;
@@ -445,6 +477,8 @@ UHCI::~UHCI()
 
 	delete [] fQueues;
 	delete [] fFrameBandwidth;
+	delete [] fFirstIsochronousDescriptor;
+	delete [] fLastIsochronousDescriptor;
 	delete fRootHub;
 	delete_area(fFrameArea);
 
@@ -551,6 +585,9 @@ UHCI::SubmitTransfer(Transfer *transfer)
 status_t
 UHCI::CancelQueuedTransfers(Pipe *pipe)
 {
+	if (pipe->Type() & USB_OBJECT_ISO_PIPE)
+		return CancelQueuedIsochronousTransfers(pipe);
+
 	if (!Lock())
 		return B_ERROR;
 
@@ -569,7 +606,7 @@ UHCI::CancelQueuedTransfers(Pipe *pipe)
 				last->link = next;
 			else
 				fFirstTransfer = next;
-			
+
 			if (fLastTransfer == current)
 				fLastTransfer = last;
 
@@ -582,11 +619,36 @@ UHCI::CancelQueuedTransfers(Pipe *pipe)
 	}
 
 	Unlock();
-	
 	return B_OK;
 }
 
 
+status_t
+UHCI::CancelQueuedIsochronousTransfers(Pipe *pipe)
+{
+	isochronous_transfer_data *current = fFirstIsochronousTransfer;
+
+	while (current) {
+		if (current->transfer->TransferPipe() == pipe) {
+			int32 packetCount
+				= current->transfer->IsochronousData()->packet_count;
+			// Set the active bit off on every descriptor in order to prevent
+			// the controller from processing them. Then set off the is_active
+			// field of the transfer in order to make the finisher thread skip
+			// the transfer. The FinishIsochronousThread will do the rest.
+			for (int32 i = 0; i < packetCount; i++)
+				current->descriptors[i]->status &= ~TD_STATUS_ACTIVE;
+			current->is_active = false;
+		}
+
+		current = current->link;
+	}
+
+	TRACE_ERROR(("usb_uhci: no isochronous transfer found!\n"));
+	return B_ERROR;
+}
+
+
 status_t
 UHCI::SubmitRequest(Transfer *transfer)
 {
@@ -685,7 +747,6 @@ UHCI::AddPendingTransfer(Transfer *transfer, Queue *queue,
 	data->transfer_queue = transferQueue;
 	data->first_descriptor = firstDescriptor;
 	data->data_descriptor = dataDescriptor;
-	data->user_area = -1;
 	data->incoming = directionIn;
 	data->link = NULL;
 
@@ -705,23 +766,215 @@ UHCI::AddPendingTransfer(Transfer *transfer, Queue *queue,
 }
 
 
+status_t
+UHCI::AddPendingIsochronousTransfer(Transfer *transfer, uhci_td **isoRequest,
+	bool directionIn)
+{
+	if (!transfer || !isoRequest)
+		return B_BAD_VALUE;
+
+	isochronous_transfer_data *data
+		= new(std::nothrow) isochronous_transfer_data;
+	if (!data)
+		return B_NO_MEMORY;
+
+	status_t result = transfer->InitKernelAccess();
+	if (result < B_OK)
+		return result;
+
+	data->transfer = transfer;
+	data->descriptors = isoRequest;
+	data->last_to_process = transfer->IsochronousData()->packet_count - 1;
+	data->incoming = directionIn;
+	data->is_active = true;
+
+	// Put in the isochronous transfer list
+	if (!LockIsochronous()) {
+		delete data;
+		return B_ERROR;
+	}
+
+	if (fLastIsochronousTransfer)
+		fLastIsochronousTransfer->link = data;
+	if (!fFirstIsochronousTransfer)
+		fFirstIsochronousTransfer = data;
+
+	fLastIsochronousTransfer = data;
+	UnlockIsochronous();
+	return B_OK;
+}
+
+
 status_t
 UHCI::SubmitIsochronous(Transfer *transfer)
 {
-	/*
-	 * This is the main isochronous method.
-	 * Here we attach one Transfer Descriptor (TD) per frame by starting
-	 * at the position specified by StartingFrameNumber. If there is
-	 * not enought bandwidth at that entry number, we find the next
-	 * available one.
-	 * The TD is obviously appended to the latest existing isochronous
-	 * TD (if any) in that frame.
-	 * Everytime a TD is added, fFrameBandiwidth[i] is decremented by
-	 * the TD bandwidth, while it is incremented once the TD has been
-	 * processed by the controller
-	 */
+	Pipe *pipe = transfer->TransferPipe();
+	bool directionIn = (pipe->Direction() == Pipe::In);
+	usb_isochronous_data *isochronousData = transfer->IsochronousData();
+	size_t packetSize = transfer->DataLength();
+	size_t restSize = packetSize % isochronousData->packet_count;
+	packetSize /= isochronousData->packet_count;
+	uint16 currentFrame;
 
-	return B_ERROR;
+	// Ignore the fact that the last descriptor might need less bandwidth.
+	// The overhead is not worthy.
+	uint16 bandwidth = transfer->Bandwidth() / isochronousData->packet_count;
+
+	TRACE(("usb_uhci: isochronous transfer descriptor bandwdith = %d\n",
+		bandwidth));
+
+	// TODO: If direction is out set every descriptor data
+	if (!directionIn)
+		return B_ERROR;
+
+	// The following holds the list of transfer descriptor of the
+	// isochronous request. It is used to quickly remove all the isochronous
+	// descriptors from the frame list, as descriptors are not link to each
+	// other in a queue like for every other transfer.
+	uhci_td **isoRequest
+		= new(std::nothrow) uhci_td *[isochronousData->packet_count];
+
+	// Create the list of transfer descriptors
+	for (uint32 i = 0; i < (isochronousData->packet_count - 1); i++) {
+		isoRequest[i] = CreateDescriptor(pipe,
+			directionIn ? TD_TOKEN_IN : TD_TOKEN_OUT, packetSize);
+		// Make sure data toggle is set to zero
+		isoRequest[i]->token &= ~TD_TOKEN_DATA1;
+	}
+
+	// Create the last transfer descriptor which should be of smaller size
+	// and set the IOC bit
+	isoRequest[isochronousData->packet_count - 1] = CreateDescriptor(pipe,
+		directionIn ? TD_TOKEN_IN : TD_TOKEN_OUT, restSize);
+	isoRequest[isochronousData->packet_count - 1]->token &= ~TD_TOKEN_DATA1;
+	isoRequest[isochronousData->packet_count - 1]->status |= TD_CONTROL_IOC;
+
+	TRACE(("usb_uhci: isochronous submitted size=%ld bytes, TDs=%ld, "
+		"packetSize=%ld, restSize=%ld\n", transfer->DataLength(),
+		isochronousData->packet_count, packetSize, restSize));
+
+	// Initialize the packet descriptors
+	for (uint32 i = 0; i < isochronousData->packet_count; i++) {
+		isochronousData->packet_descriptors[i].actual_length = 0;
+		isochronousData->packet_descriptors[i].status = B_NO_INIT;
+	}
+
+	// Find the entry where to start inserting the first Isochronous descriptor
+	if (isochronousData->flags & USB_ISO_ASAP ||
+		isochronousData->starting_frame_number == NULL) {
+		// find the first available frame with enough bandwidth.
+		// This should always be the case, as defining the starting frame
+		// number in the driver makes no sense for many reason, one of which
+		// is that frame numbers value are host controller specific, and the
+		// driver does not know which host controller is running.
+		currentFrame = ReadReg16(UHCI_FRNUM);
+
+		// Make sure that:
+		// 1. We are at least 5ms ahead the controller
+		// 2. We stay in the range 0-1023
+		// 3. There is enough bandwidth in the first entry
+		currentFrame = (currentFrame + 5) % NUMBER_OF_FRAMES;
+	} else {
+		// Find out if the frame number specified has enough bandwidth,
+		// otherwise find the first next available frame with enough bandwidth
+		currentFrame = *isochronousData->starting_frame_number;
+	}
+
+	// Find the first entry with enough bandwidth
+	// TODO: should we also check the bandwidth of the following packet_count frames?
+	uint16 startSeekingFromFrame = currentFrame;
+	while (fFrameBandwidth[currentFrame] < bandwidth) {
+		currentFrame = (currentFrame + 1) % NUMBER_OF_FRAMES;
+		if (currentFrame == startSeekingFromFrame) {
+			TRACE_ERROR(("usb_uhci: Not enough bandwidth to queue the"
+				" isochronous request. Try again later!\n"));
+			return B_ERROR;
+		}
+	}
+
+	if (isochronousData->starting_frame_number)
+		*isochronousData->starting_frame_number = currentFrame;
+
+	// Add transfer to the list
+	status_t result = AddPendingIsochronousTransfer(transfer, isoRequest,
+		directionIn);
+	if (result < B_OK) {
+		TRACE_ERROR(("usb_uhci: failed to add pending isochronous transfer\n"));
+		for (uint32 i = 0; i < isochronousData->packet_count; i++) {
+			FreeDescriptor(isoRequest[i]);
+			delete [] isoRequest;
+		}
+		return result;
+	}
+
+	TRACE(("usb_uhci: appended isochronous transfer by starting at frame"
+		" number %d\n", currentFrame));
+
+	// Insert the Transfer Descriptor by starting at
+	// the starting_frame_number entry
+	// TODO: We don't consider bInterval, and assume it's 1!
+	for (uint32 i = 0; i < isochronousData->packet_count; i++) {
+		LinkIsochronousDescriptor(isoRequest[i], currentFrame);
+		fFrameBandwidth[currentFrame] -= bandwidth;
+		currentFrame = (currentFrame + 1) % NUMBER_OF_FRAMES;
+	}
+
+	return B_OK;
+}
+
+
+isochronous_transfer_data *
+UHCI::FindIsochronousTransfer(uhci_td *descriptor)
+{
+	// Simply check every last descriptor of the isochronous transfer list
+	LockIsochronous();
+	isochronous_transfer_data *transfer = fFirstIsochronousTransfer;
+	while (transfer->descriptors[transfer->last_to_process] != descriptor) {
+		transfer = transfer->link;
+		if (!transfer)
+			break;
+	}
+
+	UnlockIsochronous();
+	return transfer;
+}
+
+
+void
+UHCI::LinkIsochronousDescriptor(uhci_td *descriptor, uint16 frame)
+{
+	// The transfer descriptor is appended to the last
+	// existing isochronous transfer descriptor (if any)
+	// in that frame.
+	if (fFrameList[frame] & FRAMELIST_NEXT_IS_QH) {
+		// Insert the transfer descriptor in the first position
+		descriptor->link_phy = fFrameList[frame];
+		// No need to set the link_log as it is already NULL
+		fFrameList[frame] = descriptor->this_phy & ~FRAMELIST_NEXT_IS_QH;
+		fFirstIsochronousDescriptor[frame] = descriptor;
+		fLastIsochronousDescriptor[frame] = descriptor;
+	} else {
+		// Append to the last transfer descriptor
+		descriptor->link_phy = fLastIsochronousDescriptor[frame]->link_phy;
+		fLastIsochronousDescriptor[frame]->link_log = descriptor;
+		fLastIsochronousDescriptor[frame]->link_phy
+			= descriptor->this_phy & ~TD_NEXT_IS_QH;
+		fLastIsochronousDescriptor[frame] = descriptor;
+	}
+}
+
+
+void
+UHCI::UnlinkIsochronousDescriptor(uhci_td *descriptor, uint16 frame)
+{
+	// The pointer to the descriptor is in descriptors[frame] and it will be
+	// freed later.
+	fFrameList[frame] = descriptor->link_phy;
+	if (fFrameList[frame] & FRAMELIST_NEXT_IS_QH) {
+		fFirstIsochronousDescriptor[frame] = NULL;
+		fLastIsochronousDescriptor[frame] = NULL;
+	} else
+		fFirstIsochronousDescriptor[frame] = (uhci_td *)descriptor->link_log;
 }
 
 
@@ -749,7 +1002,9 @@ UHCI::FinishTransfers()
 		if (!Lock())
 			continue;
 
-		TRACE(("usb_uhci: finishing transfers (first transfer: 0x%08lx; last transfer: 0x%08lx)\n", (uint32)fFirstTransfer, (uint32)fLastTransfer));
+		TRACE(("usb_uhci: finishing transfers (first transfer: 0x%08lx; last"
+			" transfer: 0x%08lx)\n", (uint32)fFirstTransfer,
+			(uint32)fLastTransfer));
 		transfer_data *lastTransfer = NULL;
 		transfer_data *transfer = fFirstTransfer;
 		Unlock();
@@ -767,7 +1022,9 @@ UHCI::FinishTransfers()
 				}
 
 				if (status & TD_ERROR_MASK) {
-					TRACE_ERROR(("usb_uhci: td (0x%08lx) error: status: 0x%08lx; token: 0x%08lx;\n", descriptor->this_phy, status, descriptor->token));
+					TRACE_ERROR(("usb_uhci: td (0x%08lx) error: status: 0x%08lx;"
+						" token: 0x%08lx;\n", descriptor->this_phy, status,
+						descriptor->token));
 					// an error occured. we have to remove the
 					// transfer from the queue and clean up
 
@@ -903,6 +1160,92 @@ UHCI::FinishTransfers()
 }
 
 
+int32
+UHCI::FinishIsochronousThread(void *data)
+{
+	((UHCI *)data)->FinishIsochronousTransfers();
+	return B_OK;
+}
+
+
+void
+UHCI::FinishIsochronousTransfers()
+{
+	/* This thread stays one position behind the controller and processes every
+	 * isochronous descriptor. Once it finds the last isochronous descriptor
+	 * of a transfer, it processes the entire transfer.
+	 */
+	uint16 currentFrame = ReadReg16(UHCI_FRNUM);
+
+	while (!fStopFinishIsochronousThread) {
+		// wait 1ms in order to be sure to be one position behind
+		// the controller
+		if (currentFrame == ReadReg16(UHCI_FRNUM))
+			snooze(1000);
+
+		// Process the frame till it has isochronous descriptors in it.
+		while (!(fFrameList[currentFrame] & FRAMELIST_NEXT_IS_QH)) {
+			uhci_td *current = fFirstIsochronousDescriptor[currentFrame];
+			UnlinkIsochronousDescriptor(current, currentFrame);
+
+			// Process the transfer if we found the last descriptor
+			if (current->status & TD_CONTROL_IOC) {
+				isochronous_transfer_data *transfer
+					= FindIsochronousTransfer(current);
+
+				// The following should NEVER happen
+				if (!transfer)
+					TRACE_ERROR(("usb_uhci: Isochronous transfer not found in"
+						" the finisher thread!\n"));
+
+				// Process the transfer only if it is still active and belongs
+				// to an INPUT transfer. If the transfer is not active, it
+				// means the request has been removed, so simply remove the
+				// descriptors.
+				else if (transfer->is_active && (current->status & TD_TOKEN_IN)) {
+					iovec *vector = transfer->transfer->Vector();
+					transfer->transfer->PrepareKernelAccess();
+					ReadIsochronousDescriptorChain(transfer, vector);
+
+					// Remove the transfer
+					if (LockIsochronous()) {
+						if (transfer == fFirstIsochronousTransfer)
+							fFirstIsochronousTransfer = transfer->link;
+						else {
+							isochronous_transfer_data *temp
+								= fFirstIsochronousTransfer;
+							while (transfer != temp->link)
+								temp = temp->link;
+
+							if (transfer == fLastIsochronousTransfer)
+								fLastIsochronousTransfer = temp;
+							temp->link = temp->link->link;
+						}
+
+						UnlockIsochronous();
+					}
+
+					transfer->transfer->Finished(B_OK, 0);
+				}
+
+				uint32 packetCount =
+					transfer->transfer->IsochronousData()->packet_count;
+				for (uint32 i = 0; i < packetCount; i++)
+					FreeDescriptor(transfer->descriptors[i]);
+
+				delete [] transfer->descriptors;
+				delete transfer->transfer;
+				delete transfer;
+			}
+		}
+
+		// Make sure to reset the frame bandwidth
+		fFrameBandwidth[currentFrame] = MAX_AVAILABLE_BANDWIDTH;
+		currentFrame = (currentFrame + 1) % NUMBER_OF_FRAMES;
+	}
+}
+
+
 void
 UHCI::GlobalReset()
 {
@@ -1292,9 +1635,14 @@ UHCI::CreateDescriptor(Pipe *pipe, uint8 direction, size_t bufferSize)
 	}
 
 	result->this_phy = (addr_t)physicalAddress;
-	result->status = TD_STATUS_ACTIVE | TD_CONTROL_3_ERRORS;
-	if (direction == TD_TOKEN_IN)
-		result->status |= TD_CONTROL_SPD;
+	result->status = TD_STATUS_ACTIVE;
+	if (pipe->Type() & USB_OBJECT_ISO_PIPE)
+		result->status |= TD_CONTROL_ISOCHRONOUS;
+	else {
+		result->status |= TD_CONTROL_3_ERRORS;
+		if (direction == TD_TOKEN_IN)
+			result->status |= TD_CONTROL_SPD;
+	}
 	if (pipe->Speed() == USB_SPEED_LOWSPEED)
 		result->status |= TD_CONTROL_LOWSPEED;
 
@@ -1315,7 +1663,7 @@ UHCI::CreateDescriptor(Pipe *pipe, uint8 direction, size_t bufferSize)
 		return result;
 	}
 
-	if (fStack->AllocateChunk(&result->buffer_log, &result->buffer_phy,
+	if (fStack->AllocateChunk(&result->buffer_log, (void **)&result->buffer_phy,
 		bufferSize) < B_OK) {
 		TRACE_ERROR(("usb_uhci: unable to allocate space for the buffer\n"));
 		fStack->FreeChunk(result, (void *)result->this_phy, sizeof(uhci_td));
@@ -1422,7 +1770,9 @@ UHCI::WriteDescriptorChain(uhci_td *topDescriptor, iovec *vector,
 			size_t length = min_c(current->buffer_size - bufferOffset,
 				vector[vectorIndex].iov_len - vectorOffset);
 
-			TRACE(("usb_uhci: copying %ld bytes to bufferOffset %ld from vectorOffset %ld at index %ld of %ld\n", length, bufferOffset, vectorOffset, vectorIndex, vectorCount));
+			TRACE(("usb_uhci: copying %ld bytes to bufferOffset %ld from"
+				" vectorOffset %ld at index %ld of %ld\n", length, bufferOffset,
+				vectorOffset, vectorIndex, vectorCount));
 			memcpy((uint8 *)current->buffer_log + bufferOffset,
 				(uint8 *)vector[vectorIndex].iov_base + vectorOffset, length);
 
@@ -1432,7 +1782,8 @@ UHCI::WriteDescriptorChain(uhci_td *topDescriptor, iovec *vector,
 
 			if (vectorOffset >= vector[vectorIndex].iov_len) {
 				if (++vectorIndex >= vectorCount) {
-					TRACE(("usb_uhci: wrote descriptor chain (%ld bytes, no more vectors)\n", actualLength));
+					TRACE(("usb_uhci: wrote descriptor chain (%ld bytes, no"
+						" more vectors)\n", actualLength));
 					return actualLength;
 				}
 
@@ -1480,7 +1831,9 @@ UHCI::ReadDescriptorChain(uhci_td *topDescriptor, iovec *vector,
 			size_t length = min_c(bufferSize - bufferOffset,
 				vector[vectorIndex].iov_len - vectorOffset);
 
-			TRACE(("usb_uhci: copying %ld bytes to vectorOffset %ld from bufferOffset %ld at index %ld of %ld\n", length, vectorOffset, bufferOffset, vectorIndex, vectorCount));
+			TRACE(("usb_uhci: copying %ld bytes to vectorOffset %ld from"
+				" bufferOffset %ld at index %ld of %ld\n", length, vectorOffset,
+				bufferOffset, vectorIndex, vectorCount));
 			memcpy((uint8 *)vector[vectorIndex].iov_base + vectorOffset,
 				(uint8 *)current->buffer_log + bufferOffset, length);
 
@@ -1548,6 +1901,52 @@ UHCI::ReadActualLength(uhci_td *topDescriptor, uint8 *lastDataToggle)
 }
 
 
+void
+UHCI::ReadIsochronousDescriptorChain(isochronous_transfer_data *transfer,
+	iovec *vector)
+{
+	size_t vectorOffset = 0;
+	usb_isochronous_data *isochronousData
+		= transfer->transfer->IsochronousData();
+
+	for (uint32 i = 0; i < isochronousData->packet_count; i++) {
+		uhci_td *current = transfer->descriptors[i];
+
+		size_t bufferSize
+			= isochronousData->packet_descriptors[i].request_length;
+		int16 actualLength = (current->status & TD_STATUS_ACTLEN_MASK) + 1;
+		if (actualLength == TD_STATUS_ACTLEN_NULL + 1)
+			actualLength = 0;
+
+		isochronousData->packet_descriptors[i].actual_length = actualLength;
+
+		if (actualLength > 0)
+			isochronousData->packet_descriptors[i].status = B_OK;
+		else
+			isochronousData->packet_descriptors[i].status = B_ERROR;
+
+		memcpy((uint8 *)vector->iov_base + vectorOffset,
+			(uint8 *)current->buffer_log, bufferSize);
+
+		vectorOffset += bufferSize;
+	}
+}
+
+
+bool
+UHCI::LockIsochronous()
+{
+	return (benaphore_lock(&fIsochronousLock) == B_OK);
+}
+
+
+void
+UHCI::UnlockIsochronous()
+{
+	benaphore_unlock(&fIsochronousLock);
+}
+
+
 inline void
 UHCI::WriteReg8(uint32 reg, uint8 value)
 {
diff --git a/src/add-ons/kernel/busses/usb/uhci.h b/src/add-ons/kernel/busses/usb/uhci.h
index 5fda3cc351..6bc9a81c88 100644
--- a/src/add-ons/kernel/busses/usb/uhci.h
+++ b/src/add-ons/kernel/busses/usb/uhci.h
@@ -5,6 +5,7 @@
  * Authors:
  *		Michael Lotz <mmlr@mlotz.ch>
  *		Niels S. Reedijk
+ *		Salvatore Benedetto <salvatore.benedetto@gmail.com>
  */
 
 #ifndef UHCI_H
@@ -61,12 +62,27 @@ typedef struct transfer_data_s {
 	uhci_qh			*transfer_queue;
 	uhci_td			*first_descriptor;
 	uhci_td			*data_descriptor;
-	area_id			user_area;
 	bool			incoming;
 	transfer_data_s	*link;
 } transfer_data;
 
 
+// This structure is used to create a list of
+// descriptors per isochronous transfer
+typedef struct isochronous_transfer_data_s {
+	Transfer					*transfer;
+	// The next field is used to keep track
+	// of every isochronous descriptor as they are NOT
+	// linked to each other in a queue like in every other
+	// transfer type
+	uhci_td						**descriptors;
+	uint16						last_to_process;
+	bool						incoming;
+	bool						is_active;
+	isochronous_transfer_data_s	*link;
+} isochronous_transfer_data;
+
+
 class UHCI : public BusManager {
 public:
 									UHCI(pci_info *info, Stack *stack);
@@ -75,6 +91,7 @@ public:
 		status_t					Start();
 virtual	status_t					SubmitTransfer(Transfer *transfer);
 virtual status_t					CancelQueuedTransfers(Pipe *pipe);
+		status_t					CancelQueuedIsochronousTransfers(Pipe *pipe);
 		status_t					SubmitRequest(Transfer *transfer);
 		status_t					SubmitIsochronous(Transfer *transfer);
 
@@ -103,6 +120,11 @@ static	int32						InterruptHandler(void *data);
 										uhci_td *firstDescriptor,
 										uhci_td *dataDescriptor,
 										bool directionIn);
+		status_t					AddPendingIsochronousTransfer(
+										Transfer *transfer,
+										uhci_td **isoRequest,
+										bool directionIn);
+
 static	int32						FinishThread(void *data);
 		void						FinishTransfers();
 
@@ -110,10 +132,25 @@ static	int32						FinishThread(void *data);
 										uhci_td **_firstDescriptor,
 										uhci_qh **_transferQueue);
 
+		// Isochronous transfer functions
+static	int32						FinishIsochronousThread(void *data);
+		void						FinishIsochronousTransfers();
+		isochronous_transfer_data	*FindIsochronousTransfer(uhci_td *descriptor);
+
+		void						LinkIsochronousDescriptor(
+										uhci_td *descriptor,
+										uint16 frame);
+		void						UnlinkIsochronousDescriptor(
+										uhci_td *descriptor,
+										uint16 frame);
+
 		// Transfer queue functions
 		uhci_qh						*CreateTransferQueue(uhci_td *descriptor);
 		void						FreeTransferQueue(uhci_qh *queueHead);
 
+		bool						LockIsochronous();
+		void						UnlockIsochronous();
+
 		// Descriptor functions
 		uhci_td						*CreateDescriptor(Pipe *pipe,
 										uint8 direction,
@@ -137,6 +174,9 @@ static	int32						FinishThread(void *data);
 										uint8 *lastDataToggle);
 		size_t						ReadActualLength(uhci_td *topDescriptor,
 										uint8 *lastDataToggle);
+		void						ReadIsochronousDescriptorChain(
+										isochronous_transfer_data *transfer,
+										iovec *vector);
 
 		// Register functions
 inline	void						WriteReg8(uint32 reg, uint8 value);
@@ -154,11 +194,17 @@ static	pci_module_info				*sPCIModule;
 
 		// Frame list memory
 		area_id						fFrameArea;
-		addr_t						*fFrameList;
+		uint32						*fFrameList;
 
-		// fFrameBandwidth[n] holds the available bandwidth 
+		// fFrameBandwidth[n] holds the available bandwidth
 		// of the nth frame in microseconds
-		int32						*fFrameBandwidth;
+		uint16						*fFrameBandwidth;
+
+		// fFirstIsochronousTransfer[n] and fLastIsochronousDescriptor[n]
+		// keeps track of the first and last isochronous transfer descriptor
+		// in the nth frame
+		uhci_td						**fFirstIsochronousDescriptor;
+		uhci_td						**fLastIsochronousDescriptor;
 
 		// Queues
 		int32						fQueueCount;
@@ -171,6 +217,13 @@ static	pci_module_info				*sPCIModule;
 		thread_id					fFinishThread;
 		bool						fStopFinishThread;
 
+		// Maintain a linked list of isochronous transfers
+		isochronous_transfer_data	*fFirstIsochronousTransfer;
+		isochronous_transfer_data	*fLastIsochronousTransfer;
+		thread_id					fFinishIsochronousThread;
+		benaphore					fIsochronousLock;
+		bool						fStopFinishIsochronousThread;
+
 		// Root hub
 		UHCIRootHub					*fRootHub;
 		uint8						fRootHubAddress;
diff --git a/src/add-ons/kernel/busses/usb/uhci_hardware.h b/src/add-ons/kernel/busses/usb/uhci_hardware.h
index e4306f0a91..217c19ff41 100644
--- a/src/add-ons/kernel/busses/usb/uhci_hardware.h
+++ b/src/add-ons/kernel/busses/usb/uhci_hardware.h
@@ -87,10 +87,10 @@
 typedef struct
 {
 	// Hardware part
-	addr_t	link_phy;		// Link to the next TD/QH
+	uint32	link_phy;		// Link to the next TD/QH
 	uint32	status;			// Status field
 	uint32	token;			// Contains the packet header (where it needs to be sent)
-	void	*buffer_phy;	// A pointer to the buffer with the actual packet
+	uint32	buffer_phy;		// A pointer to the buffer with the actual packet
 	// Software part
 	addr_t	this_phy;		// A physical pointer to this address
 	void	*link_log;		// Pointer to the next logical TD/QT
@@ -98,6 +98,8 @@ typedef struct
 	size_t	buffer_size;	// Size of the buffer
 } uhci_td;
 
+#define	TD_NEXT_IS_QH				0x02
+
 // Control and Status
 #define TD_CONTROL_SPD				(1 << 29)
 #define TD_CONTROL_3_ERRORS			(3 << 27)
@@ -142,8 +144,8 @@ typedef struct
 typedef struct
 {
 	// Hardware part
-	addr_t	link_phy;		// Link to the next TD/QH
-	addr_t	element_phy;	// Pointer to the first element in the queue
+	uint32	link_phy;		// Link to the next TD/QH
+	uint32	element_phy;	// Pointer to the first element in the queue
 	// Software part
 	addr_t	this_phy;		// The physical pointer to this address
 	void	*link_log;		// Pointer to the next logical TD/QH