diff --git a/drivers/usb/wusbcore/wa-xfer.c b/drivers/usb/wusbcore/wa-xfer.c
index a70e142..2afa886 100644
--- a/drivers/usb/wusbcore/wa-xfer.c
+++ b/drivers/usb/wusbcore/wa-xfer.c
@@ -488,13 +488,14 @@
 		&& ((segment_size + iso_frame_desc[index].length)
 				<= xfer->seg_size)) {
 		/*
-		 * For Alereon HWA devices, only include an isoc frame in a
-		 * segment if it is physically contiguous with the previous
+		 * For Alereon HWA devices, only include an isoc frame in an
+		 * out segment if it is physically contiguous with the previous
 		 * frame.  This is required because those devices expect
 		 * the isoc frames to be sent as a single USB transaction as
 		 * opposed to one transaction per frame with standard HWA.
 		 */
 		if ((xfer->wa->quirks & WUSB_QUIRK_ALEREON_HWA_CONCAT_ISOC)
+			&& (xfer->is_inbound == 0)
 			&& (index > isoc_frame_offset)
 			&& ((iso_frame_desc[index - 1].offset +
 				iso_frame_desc[index - 1].length) !=
@@ -537,14 +538,8 @@
 		result = sizeof(struct wa_xfer_bi);
 		break;
 	case USB_ENDPOINT_XFER_ISOC:
-		if (usb_pipeout(urb->pipe)) {
-			*pxfer_type = WA_XFER_TYPE_ISO;
-			result = sizeof(struct wa_xfer_hwaiso);
-		} else {
-			dev_err(dev, "FIXME: ISOC IN not implemented\n");
-			result = -ENOSYS;
-			goto error;
-		}
+		*pxfer_type = WA_XFER_TYPE_ISO;
+		result = sizeof(struct wa_xfer_hwaiso);
 		break;
 	default:
 		/* never happens */
@@ -555,10 +550,22 @@
 	xfer->is_dma = urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP ? 1 : 0;
 
 	maxpktsize = le16_to_cpu(rpipe->descr.wMaxPacketSize);
+	xfer->seg_size = le16_to_cpu(rpipe->descr.wBlocks)
+		* 1 << (xfer->wa->wa_descr->bRPipeBlockSize - 1);
+	/* Compute the segment size and make sure it is a multiple of
+	 * the maxpktsize (WUSB1.0[8.3.3.1])...not really too much of
+	 * a check (FIXME) */
+	if (xfer->seg_size < maxpktsize) {
+		dev_err(dev,
+			"HW BUG? seg_size %zu smaller than maxpktsize %zu\n",
+			xfer->seg_size, maxpktsize);
+		result = -EINVAL;
+		goto error;
+	}
+	xfer->seg_size = (xfer->seg_size / maxpktsize) * maxpktsize;
 	if ((rpipe->descr.bmAttribute & 0x3) == USB_ENDPOINT_XFER_ISOC) {
 		int index = 0;
 
-		xfer->seg_size = maxpktsize;
 		xfer->segs = 0;
 		/*
 		 * loop over urb->number_of_packets to determine how many
@@ -571,19 +578,6 @@
 			++xfer->segs;
 		}
 	} else {
-		xfer->seg_size = le16_to_cpu(rpipe->descr.wBlocks)
-			* 1 << (xfer->wa->wa_descr->bRPipeBlockSize - 1);
-		/* Compute the segment size and make sure it is a multiple of
-		 * the maxpktsize (WUSB1.0[8.3.3.1])...not really too much of
-		 * a check (FIXME) */
-		if (xfer->seg_size < maxpktsize) {
-			dev_err(dev,
-				"HW BUG? seg_size %zu smaller than maxpktsize %zu\n",
-				xfer->seg_size, maxpktsize);
-			result = -EINVAL;
-			goto error;
-		}
-		xfer->seg_size = (xfer->seg_size / maxpktsize) * maxpktsize;
 		xfer->segs = DIV_ROUND_UP(urb->transfer_buffer_length,
 						xfer->seg_size);
 		if (xfer->segs == 0 && *pxfer_type == WA_XFER_TYPE_CTL)
@@ -844,7 +838,7 @@
 				wa_xfer_id(xfer), seg->index, urb->status);
 		if (edc_inc(&wa->nep_edc, EDC_MAX_ERRORS,
 			    EDC_ERROR_TIMEFRAME)){
-			dev_err(dev, "DTO: URB max acceptable errors exceeded, resetting device\n");
+			dev_err(dev, "iso xfer: URB max acceptable errors exceeded, resetting device\n");
 			wa_reset_all(wa);
 		}
 		if (seg->status != WA_SEG_ERROR) {
@@ -1108,7 +1102,7 @@
 	const struct usb_endpoint_descriptor *dto_epd = xfer->wa->dto_epd;
 	struct wa_seg *seg;
 	size_t buf_itr, buf_size, buf_itr_size;
-	int xfer_isoc_frame_offset = 0;
+	int isoc_frame_offset = 0;
 
 	result = -ENOMEM;
 	xfer->seg = kcalloc(xfer->segs, sizeof(xfer->seg[0]), GFP_ATOMIC);
@@ -1121,10 +1115,14 @@
 		size_t iso_pkt_descr_size = 0;
 		int seg_isoc_frame_count = 0, seg_isoc_size = 0;
 
+		/*
+		 * Adjust the size of the segment object to contain space for
+		 * the isoc packet descriptor buffer.
+		 */
 		if (usb_pipeisoc(xfer->urb->pipe)) {
 			seg_isoc_frame_count =
 				__wa_seg_calculate_isoc_frame_count(xfer,
-					xfer_isoc_frame_offset, &seg_isoc_size);
+					isoc_frame_offset, &seg_isoc_size);
 
 			iso_pkt_descr_size =
 				sizeof(struct wa_xfer_packet_info_hwaiso) +
@@ -1137,15 +1135,40 @@
 		wa_seg_init(seg);
 		seg->xfer = xfer;
 		seg->index = cnt;
-		seg->isoc_frame_count = seg_isoc_frame_count;
-		seg->isoc_frame_offset = xfer_isoc_frame_offset;
-		seg->isoc_size = seg_isoc_size;
 		usb_fill_bulk_urb(&seg->tr_urb, usb_dev,
 				  usb_sndbulkpipe(usb_dev,
 						  dto_epd->bEndpointAddress),
 				  &seg->xfer_hdr, xfer_hdr_size,
 				  wa_seg_tr_cb, seg);
 		buf_itr_size = min(buf_size, xfer->seg_size);
+
+		if (usb_pipeisoc(xfer->urb->pipe)) {
+			seg->isoc_frame_count = seg_isoc_frame_count;
+			seg->isoc_frame_offset = isoc_frame_offset;
+			seg->isoc_size = seg_isoc_size;
+			/* iso packet descriptor. */
+			seg->isoc_pack_desc_urb =
+					usb_alloc_urb(0, GFP_ATOMIC);
+			if (seg->isoc_pack_desc_urb == NULL)
+				goto error_iso_pack_desc_alloc;
+			/*
+			 * The buffer for the isoc packet descriptor starts
+			 * after the transfer request header in the
+			 * segment object memory buffer.
+			 */
+			usb_fill_bulk_urb(
+				seg->isoc_pack_desc_urb, usb_dev,
+				usb_sndbulkpipe(usb_dev,
+					dto_epd->bEndpointAddress),
+				(void *)(&seg->xfer_hdr) +
+					xfer_hdr_size,
+				iso_pkt_descr_size,
+				wa_seg_iso_pack_desc_cb, seg);
+
+			/* adjust starting frame offset for next seg. */
+			isoc_frame_offset += seg_isoc_frame_count;
+		}
+
 		if (xfer->is_inbound == 0 && buf_size > 0) {
 			/* outbound data. */
 			seg->dto_urb = usb_alloc_urb(0, GFP_ATOMIC);
@@ -1158,25 +1181,6 @@
 				NULL, 0, wa_seg_dto_cb, seg);
 
 			if (usb_pipeisoc(xfer->urb->pipe)) {
-				/* iso packet descriptor. */
-				seg->isoc_pack_desc_urb =
-						usb_alloc_urb(0, GFP_ATOMIC);
-				if (seg->isoc_pack_desc_urb == NULL)
-					goto error_iso_pack_desc_alloc;
-				/*
-				 * The buffer for the isoc packet descriptor
-				 * after the transfer request header in the
-				 * segment object memory buffer.
-				 */
-				usb_fill_bulk_urb(
-					seg->isoc_pack_desc_urb, usb_dev,
-					usb_sndbulkpipe(usb_dev,
-						dto_epd->bEndpointAddress),
-					(void *)(&seg->xfer_hdr) +
-						xfer_hdr_size,
-					iso_pkt_descr_size,
-					wa_seg_iso_pack_desc_cb, seg);
-
 				/*
 				 * Fill in the xfer buffer information for the
 				 * first isoc frame.  Subsequent frames in this
@@ -1184,9 +1188,7 @@
 				 * DTO completion routine, if needed.
 				 */
 				__wa_populate_dto_urb_isoc(xfer, seg,
-					xfer_isoc_frame_offset);
-				/* adjust starting frame offset for next seg. */
-				xfer_isoc_frame_offset += seg_isoc_frame_count;
+					seg->isoc_frame_offset);
 			} else {
 				/* fill in the xfer buffer information. */
 				result = __wa_populate_dto_urb(xfer, seg,
@@ -1207,10 +1209,11 @@
 	 * Use the fact that cnt is left at were it failed.  The remaining
 	 * segments will be cleaned up by wa_xfer_destroy.
 	 */
-error_iso_pack_desc_alloc:
 error_seg_outbound_populate:
 	usb_free_urb(xfer->seg[cnt]->dto_urb);
 error_dto_alloc:
+	usb_free_urb(xfer->seg[cnt]->isoc_pack_desc_urb);
+error_iso_pack_desc_alloc:
 	kfree(xfer->seg[cnt]);
 	xfer->seg[cnt] = NULL;
 error_seg_kmalloc:
@@ -1325,8 +1328,6 @@
 	}
 	/* submit the isoc packet descriptor if present. */
 	if (seg->isoc_pack_desc_urb) {
-		struct wahc *wa = xfer->wa;
-
 		result = usb_submit_urb(seg->isoc_pack_desc_urb, GFP_ATOMIC);
 		seg->isoc_frame_index = 0;
 		if (result < 0) {
@@ -1334,6 +1335,16 @@
 			       __func__, xfer, seg->index, result);
 			goto error_iso_pack_desc_submit;
 		}
+	}
+	/* submit the out data if this is an out request. */
+	if (seg->dto_urb) {
+		struct wahc *wa = xfer->wa;
+		result = usb_submit_urb(seg->dto_urb, GFP_ATOMIC);
+		if (result < 0) {
+			pr_err("%s: xfer %p#%u: DTO submit failed: %d\n",
+			       __func__, xfer, seg->index, result);
+			goto error_dto_submit;
+		}
 		/*
 		 * If this segment contains more than one isoc frame, hold
 		 * onto the dto resource until we send all frames.
@@ -1343,15 +1354,6 @@
 			&& (seg->isoc_frame_count > 1))
 			*dto_done = 0;
 	}
-	/* submit the out data if this is an out request. */
-	if (seg->dto_urb) {
-		result = usb_submit_urb(seg->dto_urb, GFP_ATOMIC);
-		if (result < 0) {
-			pr_err("%s: xfer %p#%u: DTO submit failed: %d\n",
-			       __func__, xfer, seg->index, result);
-			goto error_dto_submit;
-		}
-	}
 	seg->status = WA_SEG_SUBMITTED;
 	rpipe_avail_dec(rpipe);
 	return 0;
@@ -2032,6 +2034,25 @@
 	}
 }
 
+/* Populate the wa->buf_in_urb based on the current isoc transfer state. */
+static void __wa_populate_buf_in_urb_isoc(struct wahc *wa, struct wa_xfer *xfer,
+	struct wa_seg *seg, int curr_iso_frame)
+{
+	BUG_ON(wa->buf_in_urb->status == -EINPROGRESS);
+
+	/* this should always be 0 before a resubmit. */
+	wa->buf_in_urb->num_mapped_sgs	= 0;
+	wa->buf_in_urb->transfer_dma = xfer->urb->transfer_dma +
+		xfer->urb->iso_frame_desc[curr_iso_frame].offset;
+	wa->buf_in_urb->transfer_buffer_length =
+		xfer->urb->iso_frame_desc[curr_iso_frame].length;
+	wa->buf_in_urb->transfer_flags |= URB_NO_TRANSFER_DMA_MAP;
+	wa->buf_in_urb->transfer_buffer = NULL;
+	wa->buf_in_urb->sg = NULL;
+	wa->buf_in_urb->num_sgs = 0;
+	wa->buf_in_urb->context = seg;
+}
+
 /* Populate the wa->buf_in_urb based on the current transfer state. */
 static int wa_populate_buf_in_urb(struct wahc *wa, struct wa_xfer *xfer,
 	unsigned int seg_idx, unsigned int bytes_transferred)
@@ -2143,12 +2164,13 @@
 	 */
 	if (xfer_result->bTransferSegment & 0x80)
 		wa_complete_remaining_xfer_segs(xfer, seg, WA_SEG_DONE);
-	if (usb_pipeisoc(xfer->urb->pipe)) {
+	if (usb_pipeisoc(xfer->urb->pipe)
+		&& (le32_to_cpu(xfer_result->dwNumOfPackets) > 0)) {
 		/* set up WA state to read the isoc packet status next. */
 		wa->dti_isoc_xfer_in_progress = wa_xfer_id(xfer);
 		wa->dti_isoc_xfer_seg = seg_idx;
 		wa->dti_state = WA_DTI_ISOC_PACKET_STATUS_PENDING;
-	} else if ((xfer->is_inbound)
+	} else if (xfer->is_inbound && !usb_pipeisoc(xfer->urb->pipe)
 			&& (bytes_transferred > 0)) {
 		/* IN data phase: read to buffer */
 		seg->status = WA_SEG_DTI_PENDING;
@@ -2241,7 +2263,7 @@
  *
  * inbound transfers: need to schedule a buf_in_urb read
  */
-static void wa_process_iso_packet_status(struct wahc *wa, struct urb *urb)
+static int wa_process_iso_packet_status(struct wahc *wa, struct urb *urb)
 {
 	struct device *dev = &wa->usb_iface->dev;
 	struct wa_xfer_packet_status_hwaiso *packet_status;
@@ -2250,8 +2272,8 @@
 	unsigned long flags;
 	struct wa_seg *seg;
 	struct wa_rpipe *rpipe;
-	unsigned done = 0;
-	unsigned rpipe_ready = 0, seg_index;
+	unsigned done = 0, dti_busy = 0, data_frame_count = 0, seg_index;
+	unsigned first_frame_index = 0, rpipe_ready = 0;
 	int expected_size;
 
 	/* We have a xfer result buffer; check it */
@@ -2287,18 +2309,48 @@
 			le16_to_cpu(packet_status->wLength));
 		goto error_bad_seg;
 	}
-	/* isoc packet status and lengths back xfer urb. */
+	/* write isoc packet status and lengths back to the xfer urb. */
 	status_array = packet_status->PacketStatus;
+	xfer->urb->start_frame =
+		wa->wusb->usb_hcd.driver->get_frame_number(&wa->wusb->usb_hcd);
 	for (seg_index = 0; seg_index < seg->isoc_frame_count; ++seg_index) {
-		xfer->urb->iso_frame_desc[seg->index].status =
+		struct usb_iso_packet_descriptor *iso_frame_desc =
+			xfer->urb->iso_frame_desc;
+		const int urb_frame_index =
+			seg->isoc_frame_offset + seg_index;
+
+		iso_frame_desc[urb_frame_index].status =
 			wa_xfer_status_to_errno(
 			le16_to_cpu(status_array[seg_index].PacketStatus));
-		xfer->urb->iso_frame_desc[seg->index].actual_length =
+		iso_frame_desc[urb_frame_index].actual_length =
 			le16_to_cpu(status_array[seg_index].PacketLength);
+		/* track the number of frames successfully transferred. */
+		if (iso_frame_desc[urb_frame_index].actual_length > 0) {
+			/* save the starting frame index for buf_in_urb. */
+			if (!data_frame_count)
+				first_frame_index = seg_index;
+			++data_frame_count;
+		}
 	}
 
-	if (!xfer->is_inbound) {
-		/* OUT transfer, complete it -- */
+	if (xfer->is_inbound && data_frame_count) {
+		int result;
+
+		seg->isoc_frame_index = first_frame_index;
+		/* submit a read URB for the first frame with data. */
+		__wa_populate_buf_in_urb_isoc(wa, xfer, seg,
+			seg->isoc_frame_index + seg->isoc_frame_offset);
+
+		result = usb_submit_urb(wa->buf_in_urb, GFP_ATOMIC);
+		if (result < 0) {
+			dev_err(dev, "DTI Error: Could not submit buf in URB (%d)",
+				result);
+			wa_reset_all(wa);
+		} else if (data_frame_count > 1)
+			/* If we need to read multiple frames, set DTI busy. */
+			dti_busy = 1;
+	} else {
+		/* OUT transfer or no more IN data, complete it -- */
 		seg->status = WA_SEG_DONE;
 		xfer->segs_done++;
 		rpipe_ready = rpipe_avail_inc(rpipe);
@@ -2311,13 +2363,13 @@
 	if (rpipe_ready)
 		wa_xfer_delayed_run(rpipe);
 	wa_xfer_put(xfer);
-	return;
+	return dti_busy;
 
 error_bad_seg:
 	spin_unlock_irqrestore(&xfer->lock, flags);
 	wa_xfer_put(xfer);
 error_parse_buffer:
-	return;
+	return dti_busy;
 }
 
 /*
@@ -2337,7 +2389,7 @@
 	struct wahc *wa;
 	struct device *dev;
 	struct wa_rpipe *rpipe;
-	unsigned rpipe_ready;
+	unsigned rpipe_ready = 0, seg_index, isoc_data_frame_count = 0;
 	unsigned long flags;
 	u8 done = 0;
 
@@ -2345,19 +2397,61 @@
 	kfree(urb->sg);
 	urb->sg = NULL;
 
+	spin_lock_irqsave(&xfer->lock, flags);
+	wa = xfer->wa;
+	dev = &wa->usb_iface->dev;
+
+	if (usb_pipeisoc(xfer->urb->pipe)) {
+		/*
+		 * Find the next isoc frame with data.  Bail out after
+		 * isoc_data_frame_count > 1 since there is no need to walk
+		 * the entire frame array.  We just need to know if
+		 * isoc_data_frame_count is 0, 1, or >1.
+		 */
+		seg_index = seg->isoc_frame_index + 1;
+		while ((seg_index < seg->isoc_frame_count)
+			&& (isoc_data_frame_count <= 1)) {
+			struct usb_iso_packet_descriptor *iso_frame_desc =
+				xfer->urb->iso_frame_desc;
+			const int urb_frame_index =
+				seg->isoc_frame_offset + seg_index;
+
+			if (iso_frame_desc[urb_frame_index].actual_length > 0) {
+				/* save the index of the next frame with data */
+				if (!isoc_data_frame_count)
+					seg->isoc_frame_index = seg_index;
+				++isoc_data_frame_count;
+			}
+			++seg_index;
+		}
+	}
+	spin_unlock_irqrestore(&xfer->lock, flags);
+
 	switch (urb->status) {
 	case 0:
 		spin_lock_irqsave(&xfer->lock, flags);
-		wa = xfer->wa;
-		dev = &wa->usb_iface->dev;
-		rpipe = xfer->ep->hcpriv;
-		dev_dbg(dev, "xfer %p#%u: data in done (%zu bytes)\n",
-			xfer, seg->index, (size_t)urb->actual_length);
-		seg->status = WA_SEG_DONE;
-		seg->result = urb->actual_length;
-		xfer->segs_done++;
-		rpipe_ready = rpipe_avail_inc(rpipe);
-		done = __wa_xfer_is_done(xfer);
+
+		seg->result += urb->actual_length;
+		if (isoc_data_frame_count > 0) {
+			int result;
+			/* submit a read URB for the first frame with data. */
+			__wa_populate_buf_in_urb_isoc(wa, xfer, seg,
+				seg->isoc_frame_index + seg->isoc_frame_offset);
+			result = usb_submit_urb(wa->buf_in_urb, GFP_ATOMIC);
+			if (result < 0) {
+				dev_err(dev, "DTI Error: Could not submit buf in URB (%d)",
+					result);
+				wa_reset_all(wa);
+			}
+		} else {
+			rpipe = xfer->ep->hcpriv;
+			seg->status = WA_SEG_DONE;
+			dev_dbg(dev, "xfer %p#%u: data in done (%zu bytes)\n",
+				xfer, seg->index, seg->result);
+			xfer->segs_done++;
+			rpipe_ready = rpipe_avail_inc(rpipe);
+			done = __wa_xfer_is_done(xfer);
+		}
 		spin_unlock_irqrestore(&xfer->lock, flags);
 		if (done)
 			wa_xfer_completion(xfer);
@@ -2369,8 +2463,6 @@
 		break;
 	default:		/* Other errors ... */
 		spin_lock_irqsave(&xfer->lock, flags);
-		wa = xfer->wa;
-		dev = &wa->usb_iface->dev;
 		rpipe = xfer->ep->hcpriv;
 		if (printk_ratelimit())
 			dev_err(dev, "xfer %p#%u: data in error %d\n",
@@ -2393,6 +2485,20 @@
 		if (rpipe_ready)
 			wa_xfer_delayed_run(rpipe);
 	}
+	/*
+	 * If we are in this callback and isoc_data_frame_count > 0, it means
+	 * that the dti_urb submission was delayed in wa_dti_cb.  Once
+	 * isoc_data_frame_count gets to 1, we can submit the deferred URB
+	 * since the last buf_in_urb was just submitted.
+	 */
+	if (isoc_data_frame_count == 1) {
+		int result = usb_submit_urb(wa->dti_urb, GFP_ATOMIC);
+		if (result < 0) {
+			dev_err(dev, "DTI Error: Could not submit DTI URB (%d)\n",
+				result);
+			wa_reset_all(wa);
+		}
+	}
 }
 
 /*
@@ -2423,7 +2529,7 @@
  */
 static void wa_dti_cb(struct urb *urb)
 {
-	int result;
+	int result, dti_busy = 0;
 	struct wahc *wa = urb->context;
 	struct device *dev = &wa->usb_iface->dev;
 	u32 xfer_id;
@@ -2471,7 +2577,7 @@
 			wa_xfer_result_chew(wa, xfer, xfer_result);
 			wa_xfer_put(xfer);
 		} else if (wa->dti_state == WA_DTI_ISOC_PACKET_STATUS_PENDING) {
-			wa_process_iso_packet_status(wa, urb);
+			dti_busy = wa_process_iso_packet_status(wa, urb);
 		} else {
 			dev_err(dev, "DTI Error: unexpected EP state = %d\n",
 				wa->dti_state);
@@ -2494,12 +2600,15 @@
 			dev_err(dev, "DTI: URB error %d\n", urb->status);
 		break;
 	}
-	/* Resubmit the DTI URB */
-	result = usb_submit_urb(wa->dti_urb, GFP_ATOMIC);
-	if (result < 0) {
-		dev_err(dev, "DTI Error: Could not submit DTI URB (%d), "
-			"resetting\n", result);
-		wa_reset_all(wa);
+
+	/* Resubmit the DTI URB if we are not busy processing isoc in frames. */
+	if (!dti_busy) {
+		result = usb_submit_urb(wa->dti_urb, GFP_ATOMIC);
+		if (result < 0) {
+			dev_err(dev, "DTI Error: Could not submit DTI URB (%d)\n",
+				result);
+			wa_reset_all(wa);
+		}
 	}
 out:
 	return;
@@ -2566,8 +2675,8 @@
 		NULL, 0, wa_buf_in_cb, wa);
 	result = usb_submit_urb(wa->dti_urb, GFP_KERNEL);
 	if (result < 0) {
-		dev_err(dev, "DTI Error: Could not submit DTI URB (%d), "
-			"resetting\n", result);
+		dev_err(dev, "DTI Error: Could not submit DTI URB (%d) resetting\n",
+			result);
 		goto error_dti_urb_submit;
 	}
 out: