diff --git a/drivers/usb/usbssp/gadget-ring.c b/drivers/usb/usbssp/gadget-ring.c
new file mode 100644
index 000000000000..958ae27d88f2
--- /dev/null
+++ b/drivers/usb/usbssp/gadget-ring.c
@@ -0,0 +1,3925 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * USBSSP device controller driver
+ *
+ * Copyright (C) 2018 Cadence.
+ *
+ * Author: Pawel Laszczak
+ * Code borrowed from the Linux XHCI driver.
+ */
+
+/*
+ * Ring initialization rules:
+ * 1. Each segment is initialized to zero, except for link TRBs.
+ * 2. Ring cycle state = 0.  This represents Producer Cycle State (PCS) or
+ *    Consumer Cycle State (CCS), depending on ring function.
+ * 3. Enqueue pointer = dequeue pointer = address of first TRB in the segment.
+ *
+ * Ring behavior rules:
+ * 1. A ring is empty if enqueue == dequeue.  This means there will always be at
+ *    least one free TRB in the ring.  This is useful if you want to turn that
+ *    into a link TRB and expand the ring.
+ * 2. When incrementing an enqueue or dequeue pointer, if the next TRB is a
+ *    link TRB, then load the pointer with the address in the link TRB.  If the
+ *    link TRB had its toggle bit set, you may need to update the ring cycle
+ *    state (see cycle bit rules).  You may have to do this multiple times
+ *    until you reach a non-link TRB.
+ * 3. A ring is full if enqueue++ (for the definition of increment above)
+ *    equals the dequeue pointer.
+ *
+ * Cycle bit rules:
+ * 1. When a consumer increments a dequeue pointer and encounters a toggle bit
+ *    in a link TRB, it must toggle the ring cycle state.
+ * 2. When a producer increments an enqueue pointer and encounters a toggle bit
+ *    in a link TRB, it must toggle the ring cycle state.
+ *
+ * Producer rules:
+ * 1. Check if ring is full before you enqueue.
+ * 2. Write the ring cycle state to the cycle bit in the TRB you're enqueuing.
+ *    Update enqueue pointer between each write (which may update the ring
+ *    cycle state).
+ * 3. Notify consumer.  If SW is producer, it rings the doorbell for command
+ *    and endpoint rings.  If DC is the producer for the event ring,
+ *    and it generates an interrupt according to interrupt modulation rules.
+ *
+ * Consumer rules:
+ * 1. Check if TRB belongs to you.  If the cycle bit == your ring cycle state,
+ *    the TRB is owned by the consumer.
+ * 2. Update dequeue pointer (which may update the ring cycle state) and
+ *    continue processing TRBs until you reach a TRB which is not owned by you.
+ * 3. Notify the producer.  SW is the consumer for the event ring, and it
+ *   updates event ring dequeue pointer.  DC is the consumer for the command and
+ *   endpoint rings; it generates events on the event ring for these.
+ */
+
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/dma-mapping.h>
+#include "gadget-trace.h"
+#include "gadget.h"
+
+static void giveback_first_trb(struct usbssp_udc *usbssp_data,
+			       unsigned int ep_index,
+			       unsigned int stream_id,
+			       int start_cycle,
+			       struct usbssp_generic_trb
+			       *start_trb);
+/*
+ * Returns zero if the TRB isn't in this segment, otherwise it returns the DMA
+ * address of the TRB.
+ */
+dma_addr_t usbssp_trb_virt_to_dma(struct usbssp_segment *seg,
+				  union usbssp_trb *trb)
+{
+	unsigned long segment_offset;
+
+	if (!seg || !trb || trb < seg->trbs)
+		return 0;
+	/* offset in TRBs */
+	segment_offset = trb - seg->trbs;
+	if (segment_offset >= TRBS_PER_SEGMENT)
+		return 0;
+	return seg->dma + (segment_offset * sizeof(*trb));
+}
+
+static bool trb_is_noop(union usbssp_trb *trb)
+{
+	return TRB_TYPE_NOOP_LE32(trb->generic.field[3]);
+}
+
+static bool trb_is_link(union usbssp_trb *trb)
+{
+	return TRB_TYPE_LINK_LE32(trb->link.control);
+}
+
+static bool last_trb_on_seg(struct usbssp_segment *seg, union usbssp_trb *trb)
+{
+	return trb == &seg->trbs[TRBS_PER_SEGMENT - 1];
+}
+
+static bool last_trb_on_ring(struct usbssp_ring *ring,
+			     struct usbssp_segment *seg,
+			     union usbssp_trb *trb)
+{
+	return last_trb_on_seg(seg, trb) && (seg->next == ring->first_seg);
+}
+
+static bool link_trb_toggles_cycle(union usbssp_trb *trb)
+{
+	return le32_to_cpu(trb->link.control) & LINK_TOGGLE;
+}
+
+static bool last_td_in_request(struct usbssp_td *td)
+{
+	struct usbssp_request *req_priv = td->priv_request;
+
+	return req_priv->num_tds_done == req_priv->num_tds;
+}
+
+static void inc_td_cnt(struct usbssp_request *priv_req)
+{
+	priv_req->num_tds_done++;
+}
+
+static void trb_to_noop(union usbssp_trb *trb, u32 noop_type)
+{
+	if (trb_is_link(trb)) {
+		/* unchain chained link TRBs */
+		trb->link.control &= cpu_to_le32(~TRB_CHAIN);
+	} else {
+		trb->generic.field[0] = 0;
+		trb->generic.field[1] = 0;
+		trb->generic.field[2] = 0;
+		/* Preserve only the cycle bit of this TRB */
+		trb->generic.field[3] &= cpu_to_le32(TRB_CYCLE);
+		trb->generic.field[3] |= cpu_to_le32(TRB_TYPE(noop_type));
+	}
+}
+
+/* Updates trb to point to the next TRB in the ring, and updates seg if the next
+ * TRB is in a new segment.  This does not skip over link TRBs, and it does not
+ * effect the ring dequeue or enqueue pointers.
+ */
+static void next_trb(struct usbssp_udc *usbssp_data,
+		     struct usbssp_ring *ring,
+		     struct usbssp_segment **seg,
+		     union usbssp_trb **trb)
+{
+	if (trb_is_link(*trb)) {
+		*seg = (*seg)->next;
+		*trb = ((*seg)->trbs);
+	} else {
+		(*trb)++;
+	}
+}
+
+/*
+ * See Cycle bit rules. SW is the consumer for the event ring only.
+ * Don't make a ring full of link TRBs.  That would be dumb and this would loop.
+ */
+void inc_deq(struct usbssp_udc *usbssp_data, struct usbssp_ring *ring)
+{
+	/* event ring doesn't have link trbs, check for last trb */
+	if (ring->type == TYPE_EVENT) {
+		if (!last_trb_on_seg(ring->deq_seg, ring->dequeue)) {
+			ring->dequeue++;
+			goto out;
+		}
+		if (last_trb_on_ring(ring, ring->deq_seg, ring->dequeue))
+			ring->cycle_state ^= 1;
+		ring->deq_seg = ring->deq_seg->next;
+		ring->dequeue = ring->deq_seg->trbs;
+		goto out;
+	}
+
+	/* All other rings have link trbs */
+	if (!trb_is_link(ring->dequeue)) {
+		ring->dequeue++;
+		ring->num_trbs_free++;
+	}
+	while (trb_is_link(ring->dequeue)) {
+		ring->deq_seg = ring->deq_seg->next;
+		ring->dequeue = ring->deq_seg->trbs;
+	}
+out:
+	trace_usbssp_inc_deq(ring);
+}
+
+/*
+ * See Cycle bit rules. SW is the consumer for the event ring only.
+ * Don't make a ring full of link TRBs.  That would be dumb and this would loop.
+ *
+ * If we've just enqueued a TRB that is in the middle of a TD (meaning the
+ * chain bit is set), then set the chain bit in all the following link TRBs.
+ * If we've enqueued the last TRB in a TD, make sure the following link TRBs
+ * have their chain bit cleared (so that each Link TRB is a separate TD).
+ *
+ * @more_trbs_coming:	Will you enqueue more TRBs before calling
+ *			prepare_transfer()?
+ */
+static void inc_enq(struct usbssp_udc *usbssp_data,
+		    struct usbssp_ring *ring,
+		    bool more_trbs_coming)
+{
+	u32 chain;
+	union usbssp_trb *next;
+
+	chain = le32_to_cpu(ring->enqueue->generic.field[3]) & TRB_CHAIN;
+	/* If this is not event ring, there is one less usable TRB */
+	if (!trb_is_link(ring->enqueue))
+		ring->num_trbs_free--;
+	next = ++(ring->enqueue);
+
+	/* Update the dequeue pointer further if that was a link TRB */
+	while (trb_is_link(next)) {
+
+		/*
+		 * If the caller doesn't plan on enqueueing more TDs before
+		 * ringing the doorbell, then we don't want to give the link TRB
+		 * to the hardware just yet. We'll give the link TRB back in
+		 * prepare_ring() just before we enqueue the TD at the top of
+		 * the ring.
+		 */
+		if (!chain && !more_trbs_coming)
+			break;
+
+		next->link.control &= cpu_to_le32(~TRB_CHAIN);
+		next->link.control |= cpu_to_le32(chain);
+
+		/* Give this link TRB to the hardware */
+		wmb();
+		next->link.control ^= cpu_to_le32(TRB_CYCLE);
+
+		/* Toggle the cycle bit after the last ring segment. */
+		if (link_trb_toggles_cycle(next))
+			ring->cycle_state ^= 1;
+
+		ring->enq_seg = ring->enq_seg->next;
+		ring->enqueue = ring->enq_seg->trbs;
+		next = ring->enqueue;
+	}
+	trace_usbssp_inc_enq(ring);
+}
+
+/*
+ * Check to see if there's room to enqueue num_trbs on the ring and make sure
+ * enqueue pointer will not advance into dequeue segment. See rules above.
+ */
+static inline int room_on_ring(struct usbssp_udc *usbssp_data,
+			       struct usbssp_ring *ring,
+			       unsigned int num_trbs)
+{
+	int num_trbs_in_deq_seg;
+
+	if (ring->num_trbs_free < num_trbs)
+		return 0;
+
+	if (ring->type != TYPE_COMMAND && ring->type != TYPE_EVENT) {
+		num_trbs_in_deq_seg = ring->dequeue - ring->deq_seg->trbs;
+
+		if (ring->num_trbs_free < num_trbs + num_trbs_in_deq_seg)
+			return 0;
+	}
+
+	return 1;
+}
+
+/* Ring the device controller doorbell after placing a command on the ring */
+void usbssp_ring_cmd_db(struct usbssp_udc *usbssp_data)
+{
+	if (!(usbssp_data->cmd_ring_state & CMD_RING_STATE_RUNNING))
+		return;
+
+	usbssp_dbg(usbssp_data, "// Ding dong command ring!\n");
+	writel(DB_VALUE_CMD, &usbssp_data->dba->doorbell[0]);
+	/* Flush PCI posted writes */
+	readl(&usbssp_data->dba->doorbell[0]);
+}
+
+static bool usbssp_mod_cmd_timer(struct usbssp_udc *usbssp_data,
+				  unsigned long delay)
+{
+	return mod_delayed_work(system_wq, &usbssp_data->cmd_timer, delay);
+	return 0;
+}
+
+static struct usbssp_command *usbssp_next_queued_cmd(
+		struct usbssp_udc *usbssp_data)
+{
+	return list_first_entry_or_null(&usbssp_data->cmd_list,
+					struct usbssp_command,
+					cmd_list);
+}
+
+/*
+ * Turn all commands on command ring with status set to "aborted" to no-op trbs.
+ * If there are other commands waiting then restart the ring and kick the timer.
+ * This must be called with command ring stopped and usbssp_data->lock held.
+ */
+static void usbssp_handle_stopped_cmd_ring(struct usbssp_udc *usbssp_data,
+					   struct usbssp_command *cur_cmd)
+{
+	struct usbssp_command *i_cmd;
+
+	/* Turn all aborted commands in list to no-ops, then restart */
+	list_for_each_entry(i_cmd, &usbssp_data->cmd_list, cmd_list) {
+
+		if (i_cmd->status != COMP_COMMAND_ABORTED)
+			continue;
+
+		i_cmd->status = COMP_COMMAND_RING_STOPPED;
+
+		usbssp_dbg(usbssp_data, "Turn aborted command %p to no-op\n",
+			 i_cmd->command_trb);
+
+		trb_to_noop(i_cmd->command_trb, TRB_CMD_NOOP);
+
+		/*
+		 * caller waiting for completion is called when command
+		 *  completion event is received for these no-op commands
+		 */
+	}
+
+	usbssp_data->cmd_ring_state = CMD_RING_STATE_RUNNING;
+
+	/* ring command ring doorbell to restart the command ring */
+	if ((usbssp_data->cmd_ring->dequeue != usbssp_data->cmd_ring->enqueue) &&
+	    !(usbssp_data->usbssp_state & USBSSP_STATE_DYING)) {
+		usbssp_data->current_cmd = cur_cmd;
+		usbssp_mod_cmd_timer(usbssp_data, USBSSP_CMD_DEFAULT_TIMEOUT);
+		usbssp_ring_cmd_db(usbssp_data);
+	}
+}
+
+/* Must be called with usbssp_data->lock held, releases and aquires lock back */
+static int usbssp_abort_cmd_ring(struct usbssp_udc *usbssp_data,
+				 unsigned long flags)
+{
+	u64 temp_64;
+	int ret;
+
+	usbssp_dbg(usbssp_data, "Abort command ring\n");
+	reinit_completion(&usbssp_data->cmd_ring_stop_completion);
+
+	temp_64 = usbssp_read_64(usbssp_data, &usbssp_data->op_regs->cmd_ring);
+	usbssp_write_64(usbssp_data, temp_64 | CMD_RING_ABORT,
+			&usbssp_data->op_regs->cmd_ring);
+
+	/* Spec says software should also time the
+	 * completion of the Command Abort operation. If CRR is not negated in 5
+	 * seconds then driver handles it as if device died (-ENODEV).
+	 */
+	ret = usbssp_handshake(&usbssp_data->op_regs->cmd_ring,
+			CMD_RING_RUNNING, 0, 5 * 1000 * 1000);
+
+	if (ret < 0) {
+		usbssp_err(usbssp_data,
+				"Abort failed to stop command ring: %d\n", ret);
+		usbssp_halt(usbssp_data);
+		usbssp_udc_died(usbssp_data);
+		return ret;
+	}
+
+	/*
+	 * Writing the CMD_RING_ABORT bit should cause a cmd completion event,
+	 * Wait 2 secs (arbitrary number).
+	 */
+	spin_unlock_irqrestore(&usbssp_data->lock, flags);
+	ret = wait_for_completion_timeout(
+			&usbssp_data->cmd_ring_stop_completion,
+			msecs_to_jiffies(2000));
+	spin_lock_irqsave(&usbssp_data->lock, flags);
+	if (!ret) {
+		usbssp_dbg(usbssp_data,
+				"No stop event for abort, ring start fail?\n");
+		usbssp_cleanup_command_queue(usbssp_data);
+	} else {
+		usbssp_handle_stopped_cmd_ring(usbssp_data,
+				usbssp_next_queued_cmd(usbssp_data));
+	}
+	return 0;
+}
+
+void usbssp_ring_ep_doorbell(struct usbssp_udc *usbssp_data,
+		unsigned int ep_index,
+		unsigned int stream_id)
+{
+	__le32 __iomem *db_addr =
+			&usbssp_data->dba->doorbell[usbssp_data->slot_id];
+	struct usbssp_ep *ep = &usbssp_data->devs.eps[ep_index];
+	unsigned int ep_state = ep->ep_state;
+	unsigned int db_value;
+	/* Don't ring the doorbell for this endpoint if there are pending
+	 * cancellations because we don't want to interrupt processing.
+	 * We don't want to restart any stream rings if there's a set dequeue
+	 * pointer command pending because the device can choose to start any
+	 * stream once the endpoint is on the HW schedule.
+	 * Also we don't want restart any endpoint if endpoint is halted or
+	 * disabled and also if endpoint disabling is pending.
+	 */
+	if ((ep_state & EP_STOP_CMD_PENDING) ||
+	    (ep_state & SET_DEQ_PENDING) ||
+	    (ep_state & EP_HALTED) ||
+	    !(ep_state & USBSSP_EP_ENABLED) ||
+	    (ep_state & USBSSP_EP_DISABLE_PENDING))
+		return;
+
+	if (ep_index == 0 && !usbssp_data->ep0_expect_in &&
+	   usbssp_data->ep0state == USBSSP_EP0_DATA_PHASE)
+		db_value = DB_VALUE_EP0_OUT(ep_index, stream_id);
+	else
+		db_value = DB_VALUE(ep_index, stream_id);
+
+	usbssp_dbg(usbssp_data, "// Ding dong transfer ring for %s!"
+			" - [DB addr/DB val]: [%p/%08x]\n",
+			usbssp_data->devs.eps[ep_index].name, db_addr,
+			db_value);
+
+	writel(db_value, db_addr);
+	/* The CPU has better things to do at this point than wait for a
+	 * write-posting flush.  It'll get there soon enough.
+	 */
+}
+
+/* Ring the doorbell for any rings with pending USB requests */
+static void ring_doorbell_for_active_rings(struct usbssp_udc *usbssp_data,
+					   unsigned int ep_index)
+{
+	unsigned int stream_id;
+	struct usbssp_ep *ep;
+
+	ep = &usbssp_data->devs.eps[ep_index];
+
+	usbssp_dbg(usbssp_data, "Ring all active ring for %s\n",
+		ep->name);
+
+	/* A ring has pending Request if its TD list is not empty */
+	if (!(ep->ep_state & EP_HAS_STREAMS)) {
+		if (ep->ring && !(list_empty(&ep->ring->td_list)))
+			usbssp_ring_ep_doorbell(usbssp_data, ep_index, 0);
+		return;
+	}
+
+	for (stream_id = 1; stream_id < ep->stream_info->num_streams;
+			stream_id++) {
+		struct usbssp_stream_info *stream_info = ep->stream_info;
+
+		if (!list_empty(&stream_info->stream_rings[stream_id]->td_list))
+			usbssp_ring_ep_doorbell(usbssp_data,  ep_index,
+					stream_id);
+	}
+}
+
+/* Get the right ring for the given ep_index and stream_id.
+ * If the endpoint supports streams, boundary check the USB request's stream ID.
+ * If the endpoint doesn't support streams, return the singular endpoint ring.
+ */
+struct usbssp_ring *usbssp_triad_to_transfer_ring(
+						struct usbssp_udc *usbssp_data,
+						unsigned int ep_index,
+						unsigned int stream_id)
+{
+	struct usbssp_ep *ep;
+
+	ep = &usbssp_data->devs.eps[ep_index];
+
+	/* Common case: no streams */
+	if (!(ep->ep_state & EP_HAS_STREAMS))
+		return ep->ring;
+
+	if (stream_id == 0) {
+		usbssp_warn(usbssp_data,
+				"WARN: ep index %u has streams, "
+				"but USB Request has no stream ID.\n",
+				 ep_index);
+		return NULL;
+	}
+
+	if (stream_id < ep->stream_info->num_streams)
+		return ep->stream_info->stream_rings[stream_id];
+
+	usbssp_warn(usbssp_data,
+			"WARN: ep index %u has "
+			"stream IDs 1 to %u allocated, "
+			"but stream ID %u is requested.\n",
+			ep_index,
+			ep->stream_info->num_streams - 1,
+			stream_id);
+	return NULL;
+}
+
+
+/*
+ * Get the hw dequeue pointer DC stopped on, either directly from the
+ * endpoint context, or if streams are in use from the stream context.
+ * The returned hw_dequeue contains the lowest four bits with cycle state
+ * and possbile stream context type.
+ */
+/*static*/ u64 usbssp_get_hw_deq(struct usbssp_udc *usbssp_data,
+				 struct usbssp_device *dev,
+				 unsigned int ep_index,
+				 unsigned int stream_id)
+{
+	struct usbssp_ep_ctx *ep_ctx;
+	struct usbssp_stream_ctx *st_ctx;
+	struct usbssp_ep *ep;
+
+	ep = &dev->eps[ep_index];
+
+	if (ep->ep_state & EP_HAS_STREAMS) {
+		st_ctx = &ep->stream_info->stream_ctx_array[stream_id];
+		return le64_to_cpu(st_ctx->stream_ring);
+	}
+	ep_ctx = usbssp_get_ep_ctx(usbssp_data, dev->out_ctx, ep_index);
+	return le64_to_cpu(ep_ctx->deq);
+}
+
+/*
+ * Move the DC endpoint ring dequeue pointer past cur_td.
+ * Record the new state of the DC endpoint ring dequeue segment,
+ * dequeue pointer, and new consumer cycle state in state.
+ * Update our internal representation of the ring's dequeue pointer.
+ *
+ * We do this in three jumps:
+ *  - First we update our new ring state to be the same as when the DC stopped.
+ *  - Then we traverse the ring to find the segment that contains
+ *    the last TRB in the TD.  We toggle the DC new cycle state when we pass
+ *    any link TRBs with the toggle cycle bit set.
+ *  - Finally we move the dequeue state one TRB further, toggling the cycle bit
+ *    if we've moved it past a link TRB with the toggle cycle bit set.
+ */
+void usbssp_find_new_dequeue_state(struct usbssp_udc *usbssp_data,
+				   unsigned int ep_index,
+				   unsigned int stream_id,
+				   struct usbssp_td *cur_td,
+				   struct usbssp_dequeue_state *state)
+{
+	struct usbssp_device *dev_priv = &usbssp_data->devs;
+	struct usbssp_ep *ep_priv = &dev_priv->eps[ep_index];
+	struct usbssp_ring *ep_ring;
+	struct usbssp_segment *new_seg;
+	union usbssp_trb *new_deq;
+	dma_addr_t addr;
+	u64 hw_dequeue;
+	bool cycle_found = false;
+	bool td_last_trb_found = false;
+
+	ep_ring = usbssp_triad_to_transfer_ring(usbssp_data,
+			ep_index, stream_id);
+	if (!ep_ring) {
+		usbssp_warn(usbssp_data, "WARN can't find new dequeue state "
+				"for invalid stream ID %u.\n",
+				stream_id);
+		return;
+	}
+
+	/* Dig out the cycle state saved by the DC during the stop ep cmd */
+	usbssp_dbg_trace(usbssp_data, trace_usbssp_dbg_cancel_request,
+			"Finding endpoint context");
+
+	hw_dequeue = usbssp_get_hw_deq(usbssp_data, dev_priv,
+			ep_index, stream_id);
+	new_seg = ep_ring->deq_seg;
+	new_deq = ep_ring->dequeue;
+	state->new_cycle_state = hw_dequeue & 0x1;
+	state->stream_id = stream_id;
+
+	/*
+	 * We want to find the pointer, segment and cycle state of the new trb
+	 * (the one after current TD's last_trb). We know the cycle state at
+	 * hw_dequeue, so walk the ring until both hw_dequeue and last_trb are
+	 * found.
+	 */
+	do {
+		if (!cycle_found && usbssp_trb_virt_to_dma(new_seg, new_deq)
+		    == (dma_addr_t)(hw_dequeue & ~0xf)) {
+			cycle_found = true;
+			if (td_last_trb_found)
+				break;
+		}
+
+		if (new_deq == cur_td->last_trb)
+			td_last_trb_found = true;
+
+		if (cycle_found && trb_is_link(new_deq) &&
+			link_trb_toggles_cycle(new_deq))
+			state->new_cycle_state ^= 0x1;
+
+		next_trb(usbssp_data, ep_ring, &new_seg, &new_deq);
+
+		/* Search wrapped around, bail out */
+		if (new_deq == ep_priv->ring->dequeue) {
+			usbssp_err(usbssp_data,
+				"Error: Failed finding new dequeue state\n");
+			state->new_deq_seg = NULL;
+			state->new_deq_ptr = NULL;
+			return;
+		}
+
+	} while (!cycle_found || !td_last_trb_found);
+
+	state->new_deq_seg = new_seg;
+	state->new_deq_ptr = new_deq;
+
+	/* Don't update the ring cycle state for the producer (us). */
+	usbssp_dbg_trace(usbssp_data, trace_usbssp_dbg_cancel_request,
+			"Cycle state = 0x%x", state->new_cycle_state);
+
+	usbssp_dbg_trace(usbssp_data, trace_usbssp_dbg_cancel_request,
+			"New dequeue segment = %p (virtual)",
+			state->new_deq_seg);
+	addr = usbssp_trb_virt_to_dma(state->new_deq_seg, state->new_deq_ptr);
+	usbssp_dbg_trace(usbssp_data, trace_usbssp_dbg_cancel_request,
+			"New dequeue pointer = 0x%llx (DMA)",
+			(unsigned long long) addr);
+}
+
+/* flip_cycle means flip the cycle bit of all but the first and last TRB.
+ * (The last TRB actually points to the ring enqueue pointer, which is not part
+ * of this TD.)  This is used to remove partially enqueued isoc TDs from a ring.
+ */
+static void td_to_noop(struct usbssp_udc *usbssp_data,
+		       struct usbssp_ring *ep_ring,
+		       struct usbssp_td *td, bool flip_cycle)
+{
+	struct usbssp_segment *seg = td->start_seg;
+	union usbssp_trb *trb = td->first_trb;
+
+	while (1) {
+		trb_to_noop(trb, TRB_TR_NOOP);
+
+		/* flip cycle if asked to */
+		if (flip_cycle && trb != td->first_trb && trb != td->last_trb)
+			trb->generic.field[3] ^= cpu_to_le32(TRB_CYCLE);
+
+		if (trb == td->last_trb)
+			break;
+
+		next_trb(usbssp_data, ep_ring, &seg, &trb);
+	}
+}
+
+/* Must be called with usbssp_data->lock held in interrupt context
+ * or usbssp_data->irq_thread_lock from thread conext (defered interrupt)
+ */
+void usbssp_giveback_request_in_irq(struct usbssp_udc *usbssp_data,
+				    struct usbssp_td *cur_td,
+				    int status)
+{
+	struct usb_request	*req;
+	struct usbssp_request	*req_priv;
+
+	req_priv = cur_td->priv_request;
+	req = &req_priv->request;
+
+	usbssp_request_free_priv(req_priv);
+
+	usbssp_gadget_giveback(req_priv->dep, req_priv, status);
+}
+
+void usbssp_unmap_td_bounce_buffer(struct usbssp_udc *usbssp_data,
+				   struct usbssp_ring *ring,
+				   struct usbssp_td *td)
+{
+	/*TODO: ??? */
+}
+
+void usbssp_remove_request(struct usbssp_udc *usbssp_data,
+			   struct usbssp_request *req_priv, int ep_index)
+{
+	int i = 0;
+	struct usbssp_ring *ep_ring;
+	struct usbssp_ep *ep;
+	struct usbssp_td *cur_td = NULL;
+	struct usbssp_ep_ctx *ep_ctx;
+	struct usbssp_device *priv_dev;
+	u64 hw_deq;
+	struct usbssp_dequeue_state deq_state;
+
+	memset(&deq_state, 0, sizeof(deq_state));
+	ep = &usbssp_data->devs.eps[ep_index];
+
+	priv_dev = &usbssp_data->devs;
+	ep_ctx = usbssp_get_ep_ctx(usbssp_data, priv_dev->out_ctx, ep_index);
+	trace_usbssp_remove_request(ep_ctx);
+	/*
+	 * We have the DC lock and disabled interrupt, so nothing can modify
+	 * this list until we drop it.
+	 */
+
+	i = req_priv->num_tds_done;
+
+	for (; i < req_priv->num_tds; i++) {
+		cur_td = &req_priv->td[i];
+		usbssp_dbg_trace(usbssp_data, trace_usbssp_dbg_cancel_request,
+			"Removing canceled TD starting at 0x%llx (dma).",
+			(unsigned long long)usbssp_trb_virt_to_dma(
+					cur_td->start_seg, cur_td->first_trb));
+
+		ep_ring = usbssp_request_to_transfer_ring(usbssp_data,
+				cur_td->priv_request);
+
+		if (!ep_ring) {
+			/* This shouldn't happen unless a driver is mucking
+			 * with the stream ID after submission.  This will
+			 * leave the TD on the hardware ring, and the hardware
+			 * will try to execute it, and may access a buffer
+			 * that has already been freed.  In the best case, the
+			 * hardware will execute it, and the event handler will
+			 * ignore the completion event for that TD, since it was
+			 * removed from the td_list for that endpoint.  In
+			 * short, don't muck with the stream ID after
+			 * submission.
+			 */
+			usbssp_warn(usbssp_data, "WARN Cancelled USB Request %p"
+					" has invalid stream ID %u.\n",
+					cur_td->priv_request,
+					cur_td->priv_request->request.stream_id);
+			goto remove_finished_td;
+		}
+
+		if (!(ep->ep_state & USBSSP_EP_ENABLED) ||
+		   ep->ep_state & USBSSP_EP_DISABLE_PENDING) {
+			goto remove_finished_td;
+		}
+
+		/*
+		 * If we stopped on the TD we need to cancel, then we have to
+		 * move the DC endpoint ring dequeue pointer past this TD.
+		 */
+		hw_deq = usbssp_get_hw_deq(usbssp_data, priv_dev, ep_index,
+				cur_td->priv_request->request.stream_id);
+		hw_deq &= ~0xf;
+
+		if (usbssp_trb_in_td(usbssp_data, cur_td->start_seg,
+			cur_td->first_trb, cur_td->last_trb, hw_deq, false)) {
+			usbssp_find_new_dequeue_state(usbssp_data, ep_index,
+					cur_td->priv_request->request.stream_id,
+					cur_td, &deq_state);
+		} else {
+			td_to_noop(usbssp_data, ep_ring, cur_td, false);
+		}
+
+remove_finished_td:
+		/*
+		 * The event handler won't see a completion for this TD anymore,
+		 * so remove it from the endpoint ring's TD list.
+		 */
+		list_del_init(&cur_td->td_list);
+	}
+
+	ep->ep_state &= ~EP_STOP_CMD_PENDING;
+
+	if (!(ep->ep_state & USBSSP_EP_DISABLE_PENDING) &&
+		ep->ep_state & USBSSP_EP_ENABLED) {
+		/* If necessary, queue a Set Transfer Ring Dequeue Pointer
+		 * command
+		 */
+		if (deq_state.new_deq_ptr && deq_state.new_deq_seg) {
+			usbssp_queue_new_dequeue_state(usbssp_data, ep_index,
+					&deq_state);
+			usbssp_ring_cmd_db(usbssp_data);
+		} else {
+			/* Otherwise ring the doorbell(s) to restart queued
+			 * transfers
+			 */
+			ring_doorbell_for_active_rings(usbssp_data, ep_index);
+		}
+	}
+
+	/*
+	 * Complete the cancellation of USB request.
+	 */
+	i = req_priv->num_tds_done;
+	for (; i < req_priv->num_tds; i++) {
+		cur_td = &req_priv->td[i];
+
+		/* Clean up the cancelled USB Request */
+		/* Doesn't matter what we pass for status, since the core will
+		 * just overwrite it.
+		 */
+		ep_ring = usbssp_request_to_transfer_ring(usbssp_data,
+				cur_td->priv_request);
+
+		usbssp_unmap_td_bounce_buffer(usbssp_data, ep_ring, cur_td);
+
+		inc_td_cnt(cur_td->priv_request);
+		if (last_td_in_request(cur_td)) {
+			usbssp_giveback_request_in_irq(usbssp_data,
+					cur_td, -ECONNRESET);
+		}
+	}
+}
+
+
+/*
+ * When we get a command completion for a Stop Endpoint Command, we need to
+ * stop timer and clear EP_STOP_CMD_PENDING flag.
+ */
+static void usbssp_handle_cmd_stop_ep(struct usbssp_udc *usbssp_data,
+				      union usbssp_trb *trb,
+				      struct usbssp_event_cmd *event)
+{
+	unsigned int ep_index;
+	struct usbssp_ep *ep;
+	struct usbssp_ep_ctx *ep_ctx;
+	struct usbssp_device *priv_dev;
+
+	ep_index = TRB_TO_EP_INDEX(le32_to_cpu(trb->generic.field[3]));
+	ep = &usbssp_data->devs.eps[ep_index];
+
+	usbssp_dbg(usbssp_data,
+		"CMD stop endpoint completion for ep index: %d - %s\n",
+		ep_index, ep->name);
+
+
+	priv_dev = &usbssp_data->devs;
+	ep_ctx = usbssp_get_ep_ctx(usbssp_data, priv_dev->out_ctx, ep_index);
+	trace_usbssp_handle_cmd_stop_ep(ep_ctx);
+
+	ep->ep_state &= ~EP_STOP_CMD_PENDING;
+}
+
+
+static void usbssp_kill_ring_requests(struct usbssp_udc *usbssp_data,
+				      struct usbssp_ring *ring)
+{
+	struct usbssp_td *cur_td;
+	struct usbssp_td *tmp;
+
+	list_for_each_entry_safe(cur_td, tmp, &ring->td_list, td_list) {
+		list_del_init(&cur_td->td_list);
+
+		usbssp_unmap_td_bounce_buffer(usbssp_data, ring, cur_td);
+		inc_td_cnt(cur_td->priv_request);
+	}
+}
+
+void usbssp_kill_endpoint_request(struct usbssp_udc *usbssp_data,
+		  int ep_index)
+{
+	struct usbssp_ep *ep;
+	struct usbssp_ring *ring;
+
+	ep = &usbssp_data->devs.eps[ep_index];
+	if ((ep->ep_state & EP_HAS_STREAMS) ||
+			(ep->ep_state & EP_GETTING_NO_STREAMS)) {
+		int stream_id;
+
+		for (stream_id = 0; stream_id < ep->stream_info->num_streams;
+		     stream_id++) {
+
+			ring = ep->stream_info->stream_rings[stream_id];
+			if (!ring)
+				continue;
+
+			usbssp_dbg_trace(usbssp_data,
+				trace_usbssp_dbg_cancel_request,
+				"Killing Requests for slot ID %u,"
+				"ep index %u, stream %u",
+				usbssp_data->slot_id, ep_index, stream_id + 1);
+			usbssp_kill_ring_requests(usbssp_data, ring);
+		}
+	} else {
+		ring = ep->ring;
+		if (!ring)
+			return;
+
+		usbssp_dbg_trace(usbssp_data, trace_usbssp_dbg_cancel_request,
+				"Killing Requests for slot ID %u, ep index %u",
+				usbssp_data->slot_id, ep_index);
+		usbssp_kill_ring_requests(usbssp_data, ring);
+	}
+}
+
+/*
+ * USBSSP controller died, register read returns 0xffffffff
+ * Complete pending commands, mark them ABORTED.
+ * USB requests need to be given back as gadget core might be waiting with
+ * device lock held for the Requests to finish during device disconnect,
+ * blocking device remove.
+ *
+ */
+
+void usbssp_udc_died(struct usbssp_udc *usbssp_data)
+{
+	int i;
+
+	if (usbssp_data->usbssp_state & USBSSP_STATE_DYING)
+		return;
+
+	usbssp_err(usbssp_data,
+			"USBSSP controller not responding, assume dead\n");
+	usbssp_data->usbssp_state |= USBSSP_STATE_DYING;
+
+	usbssp_cleanup_command_queue(usbssp_data);
+
+	/* return any pending requests, remove may be waiting for them */
+	for (i = 0; i < 31; i++)
+		usbssp_kill_endpoint_request(usbssp_data, i);
+
+}
+
+static void update_ring_for_set_deq_completion(struct usbssp_udc *usbssp_data,
+					       struct usbssp_device *dev,
+					       struct usbssp_ring *ep_ring,
+					       unsigned int ep_index)
+{
+	union usbssp_trb *dequeue_temp;
+	int num_trbs_free_temp;
+	bool revert = false;
+
+	num_trbs_free_temp = ep_ring->num_trbs_free;
+	dequeue_temp = ep_ring->dequeue;
+
+	if (trb_is_link(ep_ring->dequeue)) {
+		ep_ring->deq_seg = ep_ring->deq_seg->next;
+		ep_ring->dequeue = ep_ring->deq_seg->trbs;
+	}
+
+	while (ep_ring->dequeue != dev->eps[ep_index].queued_deq_ptr) {
+		/* We have more usable TRBs */
+		ep_ring->num_trbs_free++;
+		ep_ring->dequeue++;
+		if (trb_is_link(ep_ring->dequeue)) {
+			if (ep_ring->dequeue ==
+					dev->eps[ep_index].queued_deq_ptr)
+				break;
+			ep_ring->deq_seg = ep_ring->deq_seg->next;
+			ep_ring->dequeue = ep_ring->deq_seg->trbs;
+		}
+		if (ep_ring->dequeue == dequeue_temp) {
+			revert = true;
+			break;
+		}
+	}
+
+	if (revert) {
+		usbssp_dbg(usbssp_data, "Unable to find new dequeue pointer\n");
+		ep_ring->num_trbs_free = num_trbs_free_temp;
+	}
+}
+
+/*
+ * When we get a completion for a Set Transfer Ring Dequeue Pointer command,
+ * we need to clear the set deq pending flag in the endpoint ring state, so that
+ * the TD queueing code can ring the doorbell again.  We also need to ring the
+ * endpoint doorbell to restart the ring
+ */
+static void usbssp_handle_cmd_set_deq(struct usbssp_udc *usbssp_data,
+		union usbssp_trb *trb, u32 cmd_comp_code)
+{
+	unsigned int ep_index;
+	unsigned int stream_id;
+	struct usbssp_ring *ep_ring;
+	struct usbssp_device *dev;
+	struct usbssp_ep *ep;
+	struct usbssp_ep_ctx *ep_ctx;
+	struct usbssp_slot_ctx *slot_ctx;
+
+	ep_index = TRB_TO_EP_INDEX(le32_to_cpu(trb->generic.field[3]));
+	stream_id = TRB_TO_STREAM_ID(le32_to_cpu(trb->generic.field[2]));
+	dev = &usbssp_data->devs;
+	ep = &dev->eps[ep_index];
+
+	ep_ring = usbssp_stream_id_to_ring(dev, ep_index, stream_id);
+	if (!ep_ring) {
+		usbssp_warn(usbssp_data,
+			"WARN Set TR deq ptr command for freed stream ID %u\n",
+			stream_id);
+		/* XXX: Harmless??? */
+		goto cleanup;
+	}
+
+	ep_ctx = usbssp_get_ep_ctx(usbssp_data, dev->out_ctx, ep_index);
+	slot_ctx = usbssp_get_slot_ctx(usbssp_data, dev->out_ctx);
+	trace_usbssp_handle_cmd_set_deq(slot_ctx);
+	trace_usbssp_handle_cmd_set_deq_ep(ep_ctx);
+
+	if (cmd_comp_code != COMP_SUCCESS) {
+		unsigned int ep_state;
+		unsigned int slot_state;
+
+		switch (cmd_comp_code) {
+		case COMP_TRB_ERROR:
+			usbssp_warn(usbssp_data,
+				"WARN Set TR Deq Ptr cmd invalid because of "
+				"stream ID configuration\n");
+			break;
+		case COMP_CONTEXT_STATE_ERROR:
+			usbssp_warn(usbssp_data, "WARN Set TR Deq Ptr cmd "
+				"failed due to incorrect slot or ep state.\n");
+			ep_state = GET_EP_CTX_STATE(ep_ctx);
+			slot_state = le32_to_cpu(slot_ctx->dev_state);
+			slot_state = GET_SLOT_STATE(slot_state);
+			usbssp_dbg_trace(usbssp_data,
+					trace_usbssp_dbg_cancel_request,
+					"Slot state = %u, EP state = %u",
+					slot_state, ep_state);
+			break;
+		case COMP_SLOT_NOT_ENABLED_ERROR:
+			usbssp_warn(usbssp_data,
+					"WARN Set TR Deq Ptr cmd failed because"
+					" slot %u was not enabled.\n",
+					usbssp_data->slot_id);
+			break;
+		default:
+			usbssp_warn(usbssp_data, "WARN Set TR Deq Ptr cmd with"
+					" unknown completion code of %u.\n",
+					cmd_comp_code);
+			break;
+		}
+
+	} else {
+		u64 deq;
+		/* deq ptr is written to the stream ctx for streams */
+		if (ep->ep_state & EP_HAS_STREAMS) {
+			struct usbssp_stream_ctx *ctx =
+				&ep->stream_info->stream_ctx_array[stream_id];
+			deq = le64_to_cpu(ctx->stream_ring) & SCTX_DEQ_MASK;
+		} else {
+			deq = le64_to_cpu(ep_ctx->deq) & ~EP_CTX_CYCLE_MASK;
+		}
+		usbssp_dbg_trace(usbssp_data, trace_usbssp_dbg_cancel_request,
+			"Successful Set TR Deq Ptr cmd, deq = @%08llx", deq);
+		if (usbssp_trb_virt_to_dma(ep->queued_deq_seg,
+		    ep->queued_deq_ptr) == deq) {
+			/* Update the ring's dequeue segment and dequeue pointer
+			 * to reflect the new position.
+			 */
+			update_ring_for_set_deq_completion(usbssp_data, dev,
+				ep_ring, ep_index);
+		} else {
+			usbssp_warn(usbssp_data,
+				"Mismatch between completed Set TR Deq "
+				"Ptr command & DC internal state.\n");
+			usbssp_warn(usbssp_data,
+				"ep deq seg = %p, deq ptr = %p\n",
+				ep->queued_deq_seg, ep->queued_deq_ptr);
+		}
+	}
+
+cleanup:
+	dev->eps[ep_index].ep_state &= ~SET_DEQ_PENDING;
+	dev->eps[ep_index].queued_deq_seg = NULL;
+	dev->eps[ep_index].queued_deq_ptr = NULL;
+	/* Restart any rings with pending requests */
+	ring_doorbell_for_active_rings(usbssp_data, ep_index);
+}
+
+
+static void usbssp_handle_cmd_reset_ep(struct usbssp_udc *usbssp_data,
+				       union usbssp_trb *trb,
+				       u32 cmd_comp_code)
+{
+	struct usbssp_ep *dep;
+	struct usbssp_ep_ctx *ep_ctx;
+	unsigned int ep_index;
+
+	ep_index = TRB_TO_EP_INDEX(le32_to_cpu(trb->generic.field[3]));
+	ep_ctx = usbssp_get_ep_ctx(usbssp_data, usbssp_data->devs.out_ctx,
+			ep_index);
+	trace_usbssp_handle_cmd_reset_ep(ep_ctx);
+
+	/* This command will only fail if the endpoint wasn't halted,
+	 * but we don't care.
+	 */
+	usbssp_dbg_trace(usbssp_data, trace_usbssp_dbg_reset_ep,
+		"Ignoring reset ep completion code of %u", cmd_comp_code);
+
+	dep = &usbssp_data->devs.eps[ep_index];
+
+	/* Clear our internal halted state */
+	dep->ep_state &= ~EP_HALTED;
+
+	ring_doorbell_for_active_rings(usbssp_data, ep_index);
+}
+
+static void usbssp_handle_cmd_enable_slot(struct usbssp_udc *usbssp_data,
+					  int slot_id,
+					  struct usbssp_command *command,
+					  u32 cmd_comp_code)
+{
+	if (cmd_comp_code == COMP_SUCCESS) {
+		usbssp_dbg(usbssp_data,
+			"CMD enable slot complition successfully "
+			"- slto id: %d\n", slot_id);
+		usbssp_data->slot_id = slot_id;
+	} else {
+		usbssp_dbg(usbssp_data, "CMD enable slot complition failed\n");
+		usbssp_data->slot_id = 0;
+	}
+}
+
+static void usbssp_handle_cmd_disable_slot(struct usbssp_udc *usbssp_data)
+{
+	struct usbssp_device *dev_priv;
+	struct usbssp_slot_ctx *slot_ctx;
+
+	usbssp_dbg(usbssp_data, "CMD disable slot complition\n");
+
+	dev_priv = &usbssp_data->devs;
+	if (!dev_priv)
+		return;
+
+	usbssp_data->slot_id = 0;
+	slot_ctx = usbssp_get_slot_ctx(usbssp_data, dev_priv->out_ctx);
+	trace_usbssp_handle_cmd_disable_slot(slot_ctx);
+}
+
+static void usbssp_handle_cmd_config_ep(struct usbssp_udc *usbssp_data,
+		struct usbssp_event_cmd *event, u32 cmd_comp_code)
+{
+	struct usbssp_device *priv_dev;
+	struct usbssp_input_control_ctx *ctrl_ctx;
+	struct usbssp_ep_ctx *ep_ctx;
+	unsigned int ep_index;
+	u32 add_flags, drop_flags;
+
+	/*
+	 * Configure endpoint commands can come, becaouse device
+	 * receive USB_SET_CONFIGURATION or SET_INTERFACE request,
+	 * or because the HW needed an extra configure endpoint
+	 * command after a reset or disconnect event.
+	 */
+	priv_dev = &usbssp_data->devs;
+	ctrl_ctx = usbssp_get_input_control_ctx(priv_dev->in_ctx);
+	if (!ctrl_ctx) {
+		usbssp_warn(usbssp_data,
+				"Could not get input context, bad type.\n");
+		return;
+	}
+
+	add_flags = le32_to_cpu(ctrl_ctx->add_flags);
+	drop_flags = le32_to_cpu(ctrl_ctx->drop_flags);
+	/* Input ctx add_flags are the endpoint index plus one */
+	ep_index = usbssp_last_valid_endpoint(add_flags) - 1;
+
+	ep_ctx = usbssp_get_ep_ctx(usbssp_data, priv_dev->out_ctx, ep_index);
+	trace_usbssp_handle_cmd_config_ep(ep_ctx);
+}
+
+static void usbssp_handle_cmd_reset_dev(struct usbssp_udc *usbssp_data,
+		struct usbssp_event_cmd *event)
+{
+	struct usbssp_device *dev_priv;
+	struct usbssp_slot_ctx *slot_ctx;
+
+	dev_priv = &usbssp_data->devs;
+	slot_ctx = usbssp_get_slot_ctx(usbssp_data, dev_priv->out_ctx);
+	trace_usbssp_handle_cmd_reset_dev(slot_ctx);
+	usbssp_dbg(usbssp_data, "Completed reset device command.\n");
+	if (!usbssp_data->devs.gadget)
+		usbssp_warn(usbssp_data, "Reset device command completion\n");
+}
+
+static void usbssp_complete_del_and_free_cmd(struct usbssp_command *cmd,
+					     u32 status)
+{
+	list_del(&cmd->cmd_list);
+
+	if (cmd->completion) {
+		cmd->status = status;
+		complete(cmd->completion);
+	} else {
+		kfree(cmd);
+	}
+}
+
+void usbssp_cleanup_command_queue(struct usbssp_udc *usbssp_data)
+{
+	struct usbssp_command *cur_cmd, *tmp_cmd;
+
+	list_for_each_entry_safe(cur_cmd, tmp_cmd, &usbssp_data->cmd_list, cmd_list)
+		usbssp_complete_del_and_free_cmd(cur_cmd, COMP_COMMAND_ABORTED);
+}
+
+void usbssp_handle_command_timeout(struct work_struct *work)
+{
+	struct usbssp_udc *usbssp_data;
+	unsigned long flags;
+	u64 hw_ring_state;
+
+	usbssp_data = container_of(to_delayed_work(work), struct usbssp_udc,
+			cmd_timer);
+
+	spin_lock_irqsave(&usbssp_data->lock, flags);
+
+	/*
+	 * If timeout work is pending, or current_cmd is NULL, it means we
+	 * raced with command completion. Command is handled so just return.
+	 */
+	if (!usbssp_data->current_cmd ||
+	     delayed_work_pending(&usbssp_data->cmd_timer)) {
+		spin_unlock_irqrestore(&usbssp_data->lock, flags);
+		return;
+	}
+	/* mark this command to be cancelled */
+	usbssp_data->current_cmd->status = COMP_COMMAND_ABORTED;
+
+	/* Make sure command ring is running before aborting it */
+	hw_ring_state = usbssp_read_64(usbssp_data,
+			&usbssp_data->op_regs->cmd_ring);
+	if (hw_ring_state == ~(u64)0) {
+		usbssp_udc_died(usbssp_data);
+		goto time_out_completed;
+	}
+
+	if ((usbssp_data->cmd_ring_state & CMD_RING_STATE_RUNNING) &&
+	    (hw_ring_state & CMD_RING_RUNNING))  {
+		/* Prevent new doorbell, and start command abort */
+		usbssp_data->cmd_ring_state = CMD_RING_STATE_ABORTED;
+		usbssp_dbg(usbssp_data, "Command timeout\n");
+		usbssp_abort_cmd_ring(usbssp_data, flags);
+		goto time_out_completed;
+	}
+
+	/* device disconnected. Bail out */
+	if (usbssp_data->usbssp_state & USBSSP_STATE_REMOVING) {
+		usbssp_dbg(usbssp_data, "device removed, ring start fail?\n");
+		usbssp_cleanup_command_queue(usbssp_data);
+		goto time_out_completed;
+	}
+
+	/* command timeout on stopped ring, ring can't be aborted */
+	usbssp_dbg(usbssp_data, "Command timeout on stopped ring\n");
+	usbssp_handle_stopped_cmd_ring(usbssp_data, usbssp_data->current_cmd);
+
+time_out_completed:
+	spin_unlock_irqrestore(&usbssp_data->lock, flags);
+}
+
+static void handle_cmd_completion(struct usbssp_udc *usbssp_data,
+		struct usbssp_event_cmd *event)
+{
+	int slot_id = TRB_TO_SLOT_ID(le32_to_cpu(event->flags));
+	u64 cmd_dma;
+	dma_addr_t cmd_dequeue_dma;
+	u32 cmd_comp_code;
+	union usbssp_trb *cmd_trb;
+	struct usbssp_command *cmd;
+	u32 cmd_type;
+
+	cmd_dma = le64_to_cpu(event->cmd_trb);
+	cmd_trb = usbssp_data->cmd_ring->dequeue;
+
+	trace_usbssp_handle_command(usbssp_data->cmd_ring, &cmd_trb->generic);
+
+	cmd_dequeue_dma = usbssp_trb_virt_to_dma(usbssp_data->cmd_ring->deq_seg,
+			cmd_trb);
+
+	/*
+	 * Check whether the completion event is for our internal kept
+	 * command.
+	 */
+	if (!cmd_dequeue_dma || cmd_dma != (u64)cmd_dequeue_dma) {
+		usbssp_warn(usbssp_data,
+			  "ERROR mismatched command completion event\n");
+		return;
+	}
+
+	cmd = list_entry(usbssp_data->cmd_list.next, struct usbssp_command,
+			cmd_list);
+
+	cancel_delayed_work(&usbssp_data->cmd_timer);
+
+	cmd_comp_code = GET_COMP_CODE(le32_to_cpu(event->status));
+
+	/* If CMD ring stopped we own the trbs between enqueue and dequeue */
+	if (cmd_comp_code ==  COMP_COMMAND_RING_STOPPED) {
+		complete_all(&usbssp_data->cmd_ring_stop_completion);
+		return;
+	}
+
+	if (cmd->command_trb != usbssp_data->cmd_ring->dequeue) {
+		usbssp_err(usbssp_data,
+			 "Command completion event does not match command\n");
+		return;
+	}
+
+	/*
+	 * device aborted the command ring, check if the current command was
+	 * supposed to be aborted, otherwise continue normally.
+	 * The command ring is stopped now, but the DC will issue a Command
+	 * Ring Stopped event which will cause us to restart it.
+	 */
+	if (cmd_comp_code == COMP_COMMAND_ABORTED) {
+		usbssp_data->cmd_ring_state = CMD_RING_STATE_STOPPED;
+
+		if (cmd->status == COMP_COMMAND_ABORTED) {
+			if (usbssp_data->current_cmd == cmd)
+				usbssp_data->current_cmd = NULL;
+			goto event_handled;
+		}
+	}
+
+	cmd_type = TRB_FIELD_TO_TYPE(le32_to_cpu(cmd_trb->generic.field[3]));
+	switch (cmd_type) {
+	case TRB_ENABLE_SLOT:
+		usbssp_handle_cmd_enable_slot(usbssp_data, slot_id,
+				cmd, cmd_comp_code);
+		break;
+	case TRB_DISABLE_SLOT:
+		usbssp_handle_cmd_disable_slot(usbssp_data);
+		break;
+	case TRB_CONFIG_EP:
+		if (!cmd->completion)
+			usbssp_handle_cmd_config_ep(usbssp_data, event,
+					cmd_comp_code);
+		break;
+	case TRB_EVAL_CONTEXT:
+		break;
+	case TRB_ADDR_DEV: {
+		struct usbssp_slot_ctx *slot_ctx;
+
+		slot_ctx = usbssp_get_slot_ctx(usbssp_data,
+				usbssp_data->devs.out_ctx);
+		trace_usbssp_handle_cmd_addr_dev(slot_ctx);
+		break;
+	}
+	case TRB_STOP_RING:
+		WARN_ON(slot_id != TRB_TO_SLOT_ID(
+				le32_to_cpu(cmd_trb->generic.field[3])));
+		usbssp_handle_cmd_stop_ep(usbssp_data, cmd_trb, event);
+		break;
+	case TRB_SET_DEQ:
+		WARN_ON(slot_id != TRB_TO_SLOT_ID(
+				le32_to_cpu(cmd_trb->generic.field[3])));
+		usbssp_handle_cmd_set_deq(usbssp_data, cmd_trb, cmd_comp_code);
+		break;
+	case TRB_CMD_NOOP:
+		/* Is this an aborted command turned to NO-OP? */
+		if (cmd->status == COMP_COMMAND_RING_STOPPED)
+			cmd_comp_code = COMP_COMMAND_RING_STOPPED;
+		break;
+	case TRB_HALT_ENDPOINT:
+		if (cmd->status == COMP_COMMAND_RING_STOPPED)
+			cmd_comp_code = COMP_COMMAND_RING_STOPPED;
+		break;
+	case TRB_FLUSH_ENDPOINT:
+		if (cmd->status == COMP_COMMAND_RING_STOPPED)
+			cmd_comp_code = COMP_COMMAND_RING_STOPPED;
+		break;
+	case TRB_RESET_EP:
+		WARN_ON(slot_id != TRB_TO_SLOT_ID(
+				le32_to_cpu(cmd_trb->generic.field[3])));
+		usbssp_handle_cmd_reset_ep(usbssp_data, cmd_trb, cmd_comp_code);
+		break;
+	case TRB_RESET_DEV:
+		/* SLOT_ID field in reset device cmd completion event TRB is 0.
+		 * Use the SLOT_ID from the command TRB instead.
+		 */
+		slot_id = TRB_TO_SLOT_ID(
+				le32_to_cpu(cmd_trb->generic.field[3]));
+
+		WARN_ON(slot_id != 0);
+		usbssp_handle_cmd_reset_dev(usbssp_data, event);
+		break;
+	case TRB_FORCE_HEADER:
+		break;
+	default:
+		/* Skip over unknown commands on the event ring */
+		usbssp_info(usbssp_data, "INFO unknown command type %d\n",
+				cmd_type);
+		break;
+	}
+
+	/* restart timer if this wasn't the last command */
+	if (!list_is_singular(&usbssp_data->cmd_list)) {
+		usbssp_data->current_cmd = list_first_entry(&cmd->cmd_list,
+					struct usbssp_command, cmd_list);
+		usbssp_mod_cmd_timer(usbssp_data, USBSSP_CMD_DEFAULT_TIMEOUT);
+	} else if (usbssp_data->current_cmd == cmd) {
+		usbssp_data->current_cmd = NULL;
+	}
+
+event_handled:
+	usbssp_complete_del_and_free_cmd(cmd, cmd_comp_code);
+	inc_deq(usbssp_data, usbssp_data->cmd_ring);
+}
+
+
+static void handle_vendor_event(struct usbssp_udc *usbssp_data,
+		union usbssp_trb *event)
+{
+	u32 trb_type;
+
+	trb_type = TRB_FIELD_TO_TYPE(le32_to_cpu(event->generic.field[3]));
+	usbssp_dbg(usbssp_data,
+		"Vendor specific event or Babble TRB type = %u\n", trb_type);
+}
+
+static void handle_port_status(struct usbssp_udc *usbssp_data,
+		union usbssp_trb *event)
+{
+	u32 port_id;
+	u32 portsc, cmd_regs;
+	int max_ports;
+	u8 major_revision;
+	__le32 __iomem *port_regs;
+
+	/* Port status change events always have a successful completion code */
+	if (GET_COMP_CODE(le32_to_cpu(event->generic.field[2])) != COMP_SUCCESS)
+		usbssp_err(usbssp_data,
+			"WARN: USBSSP returned failed port status event\n");
+
+
+	port_id = GET_PORT_ID(le32_to_cpu(event->generic.field[0]));
+	usbssp_dbg(usbssp_data,
+		"Port Status Change Event for port %d\n", port_id);
+
+	usbssp_data->devs.port_num = port_id;
+	max_ports = HCS_MAX_PORTS(usbssp_data->hcs_params1);
+
+	if ((port_id <= 0) || (port_id > max_ports)) {
+		usbssp_err(usbssp_data, "Invalid port id %d\n", port_id);
+		inc_deq(usbssp_data, usbssp_data->event_ring);
+		return;
+	}
+
+	if (!usbssp_data->port_major_revision) {
+		/* Figure out to which USB port  device is attached:
+		 * is it a USB 3.0 port or a USB 2.0/1.1 port?
+		 */
+		major_revision = usbssp_data->port_array[port_id - 1];
+
+		if (major_revision == 0) {
+			usbssp_warn(usbssp_data, "Event for port %u not in "
+					"Extended Capabilities, ignoring.\n",
+					port_id);
+			goto cleanup;
+		}
+
+		usbssp_data->port_major_revision = major_revision;
+	}
+
+	port_regs = usbssp_get_port_io_addr(usbssp_data);
+
+	portsc = readl(port_regs);
+	trace_usbssp_handle_port_status(usbssp_data->devs.port_num, portsc);
+	usbssp_data->gadget.speed = usbssp_port_speed(portsc);
+	usbssp_dbg(usbssp_data, "PORTSC info: %s\n",
+			usbssp_decode_portsc(portsc));
+
+	if ((portsc & PORT_PLC) && (portsc & PORT_PLS_MASK) == XDEV_RESUME) {
+		usbssp_dbg(usbssp_data, "port resume event for port %d\n",
+				port_id);
+		cmd_regs = readl(&usbssp_data->op_regs->command);
+		if (!(cmd_regs & CMD_RUN)) {
+			usbssp_warn(usbssp_data, "DC is not running.\n");
+			goto cleanup;
+		}
+		if (DEV_SUPERSPEED_ANY(portsc)) {
+			usbssp_dbg(usbssp_data, "remote wake SS port %d\n",
+					port_id);
+			usbssp_test_and_clear_bit(usbssp_data, port_regs,
+					PORT_PLC);
+			usbssp_set_link_state(usbssp_data, port_regs, XDEV_U0);
+			usbssp_resume_gadget(usbssp_data);
+			goto cleanup;
+		}
+	}
+
+	if ((portsc & PORT_PLC) && (portsc & PORT_PLS_MASK) == XDEV_U0 &&
+			DEV_SUPERSPEED_ANY(portsc)) {
+		usbssp_dbg(usbssp_data, "resume SS port %d\n", port_id);
+		usbssp_test_and_clear_bit(usbssp_data, port_regs, PORT_PLC);
+	}
+
+	if ((portsc & PORT_PLC) && (portsc & PORT_PLS_MASK) == XDEV_U1 &&
+			DEV_SUPERSPEED_ANY(portsc)) {
+		usbssp_dbg(usbssp_data, "suspend U1 SS port %d\n", port_id);
+		usbssp_test_and_clear_bit(usbssp_data, port_regs, PORT_PLC);
+		usbssp_suspend_gadget(usbssp_data);
+	}
+
+	if ((portsc & PORT_PLC) && ((portsc & PORT_PLS_MASK) == XDEV_U2 ||
+			(portsc & PORT_PLS_MASK) == XDEV_U3)) {
+		usbssp_dbg(usbssp_data, "resume SS port %d finished\n",
+				port_id);
+		usbssp_test_and_clear_bit(usbssp_data, port_regs, PORT_PLC);
+		usbssp_suspend_gadget(usbssp_data);
+	}
+
+	/*Attach device */
+	if ((portsc & PORT_CSC) && (portsc & PORT_CONNECT)) {
+		usbssp_dbg(usbssp_data, "Port status change: Device Attached\n");
+		usbssp_data->defered_event |= EVENT_DEV_CONNECTED;
+		queue_work(usbssp_data->bottom_irq_wq,
+				&usbssp_data->bottom_irq);
+		usbssp_test_and_clear_bit(usbssp_data, port_regs, PORT_CSC);
+	}
+
+	/*Detach  device*/
+	if ((portsc & PORT_CSC) && !(portsc & PORT_CONNECT)) {
+		usbssp_dbg(usbssp_data,
+				"Port status change: Device Deattached\n");
+		usbssp_data->defered_event |= EVENT_DEV_DISCONECTED;
+		queue_work(usbssp_data->bottom_irq_wq,
+				&usbssp_data->bottom_irq);
+		usbssp_test_and_clear_bit(usbssp_data, port_regs, PORT_CSC);
+	}
+
+	/*Port Reset Change - port is in reset state */
+	if ((portsc & PORT_RC) && (portsc & PORT_RESET)) {
+		usbssp_dbg(usbssp_data,
+			"Port status change: Port reset signaling detected\n");
+		usbssp_test_and_clear_bit(usbssp_data, port_regs, PORT_RC);
+	}
+
+	/*Port Reset Change - port is not in reset state */
+	if ((portsc & PORT_RC) && !(portsc & PORT_RESET)) {
+		usbssp_dbg(usbssp_data,
+			"Port status change: Port reset completion detected\n");
+		usbssp_gadget_reset_interrupt(usbssp_data);
+		usbssp_data->defered_event |= EVENT_USB_RESET;
+		queue_work(usbssp_data->bottom_irq_wq,
+				&usbssp_data->bottom_irq);
+		usbssp_test_and_clear_bit(usbssp_data, port_regs, PORT_RC);
+	}
+
+	/*Port Warm Reset Change*/
+	if (portsc & PORT_WRC) {
+		usbssp_dbg(usbssp_data,
+			"Port status change: Port Warm Reset detected\n");
+		usbssp_test_and_clear_bit(usbssp_data, port_regs, PORT_WRC);
+	}
+
+	/*Port Over-Curretn Change*/
+	if (portsc & PORT_OCC) {
+		usbssp_dbg(usbssp_data,
+			"Port status change: Port Over Current detected\n");
+		usbssp_test_and_clear_bit(usbssp_data, port_regs, PORT_OCC);
+	}
+
+	/*Port Configure Error Change*/
+	if (portsc & PORT_CEC) {
+		usbssp_dbg(usbssp_data,
+			"Port status change: Port Configure Error detected\n");
+		usbssp_test_and_clear_bit(usbssp_data, port_regs, PORT_CEC);
+	}
+
+	if (usbssp_data->port_major_revision == 0x02) {
+		usbssp_test_and_clear_bit(usbssp_data, port_regs,
+					PORT_PLC);
+	}
+
+cleanup:
+	/* Update event ring dequeue pointer before dropping the lock */
+	inc_deq(usbssp_data, usbssp_data->event_ring);
+
+}
+
+/*
+ * This TD is defined by the TRBs starting at start_trb in start_seg and ending
+ * at end_trb, which may be in another segment.  If the suspect DMA address is a
+ * TRB in this TD, this function returns that TRB's segment.  Otherwise it
+ * returns 0.
+ */
+struct usbssp_segment *usbssp_trb_in_td(struct usbssp_udc *usbssp_data,
+					struct usbssp_segment *start_seg,
+					union usbssp_trb *start_trb,
+					union usbssp_trb *end_trb,
+					dma_addr_t suspect_dma,
+		bool		debug)
+{
+	dma_addr_t start_dma;
+	dma_addr_t end_seg_dma;
+	dma_addr_t end_trb_dma;
+	struct usbssp_segment *cur_seg;
+
+	start_dma = usbssp_trb_virt_to_dma(start_seg, start_trb);
+	cur_seg = start_seg;
+
+	do {
+		if (start_dma == 0)
+			return NULL;
+		/* We may get an event for a Link TRB in the middle of a TD */
+		end_seg_dma = usbssp_trb_virt_to_dma(cur_seg,
+				&cur_seg->trbs[TRBS_PER_SEGMENT - 1]);
+		/* If the end TRB isn't in this segment, this is set to 0 */
+		end_trb_dma = usbssp_trb_virt_to_dma(cur_seg, end_trb);
+
+		if (debug)
+			usbssp_warn(usbssp_data,
+				"Looking for event-dma %016llx trb-start"
+				"%016llx trb-end %016llx seg-start %016llx"
+				" seg-end %016llx\n",
+				(unsigned long long)suspect_dma,
+				(unsigned long long)start_dma,
+				(unsigned long long)end_trb_dma,
+				(unsigned long long)cur_seg->dma,
+				(unsigned long long)end_seg_dma);
+
+		if (end_trb_dma > 0) {
+			/* The end TRB is in this segment, so suspect should
+			 *  be here
+			 */
+			if (start_dma <= end_trb_dma) {
+				if (suspect_dma >= start_dma &&
+				    suspect_dma <= end_trb_dma)
+					return cur_seg;
+			} else {
+				/* Case for one segment with
+				 * a TD wrapped around to the top
+				 */
+				if ((suspect_dma >= start_dma &&
+						suspect_dma <= end_seg_dma) ||
+						(suspect_dma >= cur_seg->dma &&
+						 suspect_dma <= end_trb_dma))
+					return cur_seg;
+			}
+			return NULL;
+		} else {
+			/* Might still be somewhere in this segment */
+			if (suspect_dma >= start_dma &&
+			    suspect_dma <= end_seg_dma)
+				return cur_seg;
+		}
+		cur_seg = cur_seg->next;
+		start_dma = usbssp_trb_virt_to_dma(cur_seg, &cur_seg->trbs[0]);
+	} while (cur_seg != start_seg);
+
+	return NULL;
+}
+
+void usbssp_cleanup_halted_endpoint(struct usbssp_udc *usbssp_data,
+				    unsigned int ep_index,
+				    unsigned int stream_id,
+				    struct usbssp_td *td,
+				    enum usbssp_ep_reset_type reset_type)
+{
+	struct usbssp_command *command;
+	struct usbssp_ep_ctx *ep_ctx;
+	int interrupt_disabled_locally;
+
+	ep_ctx = usbssp_get_ep_ctx(usbssp_data, usbssp_data->devs.out_ctx,
+			ep_index);
+
+	if (GET_EP_CTX_STATE(ep_ctx) != EP_STATE_HALTED) {
+		usbssp_dbg(usbssp_data,
+			"Endpint index %d is not in  halted state.\n",
+			ep_index);
+		usbssp_status_stage(usbssp_data);
+		return;
+	}
+
+	command = usbssp_alloc_command(usbssp_data, true, GFP_ATOMIC);
+	if (!command)
+		return;
+
+	usbssp_queue_reset_ep(usbssp_data, command, ep_index,
+			reset_type);
+
+	usbssp_ring_cmd_db(usbssp_data);
+
+	if (irqs_disabled()) {
+		spin_unlock_irqrestore(&usbssp_data->irq_thread_lock,
+				usbssp_data->irq_thread_flag);
+		interrupt_disabled_locally = 1;
+	} else {
+		spin_unlock(&usbssp_data->irq_thread_lock);
+	}
+
+	wait_for_completion(command->completion);
+
+	if (interrupt_disabled_locally)
+		spin_lock_irqsave(&usbssp_data->irq_thread_lock,
+				usbssp_data->irq_thread_flag);
+	else
+		spin_lock(&usbssp_data->irq_thread_lock);
+
+	usbssp_free_command(usbssp_data, command);
+	if (ep_index != 0)
+		usbssp_status_stage(usbssp_data);
+}
+
+int usbssp_is_vendor_info_code(struct usbssp_udc *usbssp_data, unsigned int trb_comp_code)
+{
+	if (trb_comp_code >= 224 && trb_comp_code <= 255) {
+		/* Vendor defined "informational" completion code,
+		 * treat as not-an-error.
+		 */
+		usbssp_dbg(usbssp_data,
+				"Vendor defined info completion code %u\n",
+				trb_comp_code);
+		usbssp_dbg(usbssp_data, "Treating code as success.\n");
+		return 1;
+	}
+	return 0;
+}
+
+static int usbssp_td_cleanup(struct usbssp_udc *usbssp_data, struct usbssp_td *td,
+		struct usbssp_ring *ep_ring, int *status)
+{
+	struct usbssp_request *req_priv = NULL;
+
+	/* Clean up the endpoint's TD list */
+	req_priv = td->priv_request;
+
+	/* if a bounce buffer was used to align this td then unmap it */
+	usbssp_unmap_td_bounce_buffer(usbssp_data, ep_ring, td);
+
+	/* Do one last check of the actual transfer length.
+	 * If the DC controller said we transferred more data than the buffer
+	 * length, req_priv->request.actual will be a very big number (since it's
+	 * unsigned).  Play it safe and say we didn't transfer anything.
+	 */
+	if (req_priv->request.actual > req_priv->request.length) {
+		usbssp_warn(usbssp_data,
+			"USB req %u and actual %u transfer length mismatch\n",
+			req_priv->request.length, req_priv->request.actual);
+		req_priv->request.actual = 0;
+		*status = 0;
+	}
+	list_del_init(&td->td_list);
+
+	inc_td_cnt(req_priv);
+	/* Giveback the USB request when all the tds are completed */
+	if (last_td_in_request(td)) {
+		if ((req_priv->request.actual != req_priv->request.length &&
+		     td->priv_request->request.short_not_ok) ||
+		    (*status != 0 &&
+		     !usb_endpoint_xfer_isoc(req_priv->dep->endpoint.desc)))
+			usbssp_dbg(usbssp_data,
+				"Giveback Request %p, len = %d, expected = %d"
+				" status = %d\n",
+				req_priv, req_priv->request.actual,
+				req_priv->request.length, *status);
+
+		if (usb_endpoint_xfer_isoc(req_priv->dep->endpoint.desc))
+			*status = 0;
+
+		usbssp_giveback_request_in_irq(usbssp_data, td, *status);
+	}
+
+	return 0;
+}
+
+
+static int finish_td(struct usbssp_udc *usbssp_data, struct usbssp_td *td,
+	struct usbssp_transfer_event *event, struct usbssp_ep *ep, int *status)
+{
+	struct usbssp_device *dev_priv;
+	struct usbssp_ring *ep_ring;
+	unsigned int slot_id;
+	int ep_index;
+	struct usbssp_ep_ctx *ep_ctx;
+	u32 trb_comp_code;
+
+	slot_id = TRB_TO_SLOT_ID(le32_to_cpu(event->flags));
+	dev_priv = &usbssp_data->devs;
+	ep_index = TRB_TO_EP_ID(le32_to_cpu(event->flags)) - 1;
+	ep_ring = usbssp_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));
+	ep_ctx = usbssp_get_ep_ctx(usbssp_data, dev_priv->out_ctx, ep_index);
+	trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
+
+	if (trb_comp_code == COMP_STOPPED_LENGTH_INVALID ||
+			trb_comp_code == COMP_STOPPED ||
+			trb_comp_code == COMP_STOPPED_SHORT_PACKET) {
+		/* The Endpoint Stop Command completion will take care of any
+		 * stopped TDs.  A stopped TD may be restarted, so don't update
+		 * the ring dequeue pointer or take this TD off any lists yet.
+		 */
+		return 0;
+	}
+
+	/* Update ring dequeue pointer */
+	while (ep_ring->dequeue != td->last_trb)
+		inc_deq(usbssp_data, ep_ring);
+
+	inc_deq(usbssp_data, ep_ring);
+
+	return usbssp_td_cleanup(usbssp_data, td, ep_ring, status);
+}
+
+/* sum trb lengths from ring dequeue up to stop_trb, _excluding_ stop_trb */
+static int sum_trb_lengths(struct usbssp_udc *usbssp_data,
+			   struct usbssp_ring *ring,
+			   union usbssp_trb *stop_trb)
+{
+	u32 sum;
+	union usbssp_trb *trb = ring->dequeue;
+	struct usbssp_segment *seg = ring->deq_seg;
+
+	for (sum = 0; trb != stop_trb; next_trb(usbssp_data, ring, &seg, &trb)) {
+		if (!trb_is_noop(trb) && !trb_is_link(trb))
+			sum += TRB_LEN(le32_to_cpu(trb->generic.field[2]));
+	}
+	return sum;
+}
+
+/*
+ * Process control tds, update USB request status and actual_length.
+ */
+static int process_ctrl_td(struct usbssp_udc *usbssp_data, struct usbssp_td *td,
+	union usbssp_trb *event_trb, struct usbssp_transfer_event *event,
+	struct usbssp_ep *ep_priv, int *status)
+{
+	struct usbssp_device *dev_priv;
+	struct usbssp_ring *ep_ring;
+	unsigned int slot_id;
+	int ep_index;
+	struct usbssp_ep_ctx *ep_ctx;
+	u32 trb_comp_code;
+	u32 remaining, requested;
+	u32 trb_type;
+
+	trb_type = TRB_FIELD_TO_TYPE(le32_to_cpu(event_trb->generic.field[3]));
+	slot_id = TRB_TO_SLOT_ID(le32_to_cpu(event->flags));
+	dev_priv = &usbssp_data->devs;
+	ep_index = TRB_TO_EP_ID(le32_to_cpu(event->flags)) - 1;
+	ep_ring = usbssp_dma_to_transfer_ring(ep_priv, le64_to_cpu(event->buffer));
+	ep_ctx = usbssp_get_ep_ctx(usbssp_data, dev_priv->out_ctx, ep_index);
+	trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
+	requested = td->priv_request->request.length;
+	remaining = EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
+
+	switch (trb_comp_code) {
+	case COMP_SUCCESS:
+		*status = 0;
+		break;
+	case COMP_SHORT_PACKET:
+		*status = 0;
+		break;
+	case COMP_STOPPED_SHORT_PACKET:
+		if (trb_type == TRB_DATA || trb_type == TRB_NORMAL)
+			td->priv_request->request.actual  = remaining;
+	goto finish_td;
+	case COMP_STOPPED:
+		switch (trb_type) {
+		case TRB_DATA:
+		case TRB_NORMAL:
+			td->priv_request->request.actual =
+				requested - remaining;
+			goto finish_td;
+		case TRB_STATUS:
+			td->priv_request->request.actual = requested;
+			goto finish_td;
+		default:
+			usbssp_warn(usbssp_data,
+				"WARN: unexpected TRB Type %d\n",
+				trb_type);
+			goto finish_td;
+		}
+	case COMP_STOPPED_LENGTH_INVALID:
+		goto finish_td;
+	default:
+		usbssp_dbg(usbssp_data, "TRB error code %u, "
+			"halted endpoint index = %u\n",
+			trb_comp_code, ep_index);
+	}
+
+	/*
+	 * if on data stage then update the actual_length of the USB
+	 * request and flag it as set, so it won't be overwritten in the event
+	 * for the last TRB.
+	 */
+	if (trb_type == TRB_DATA ||
+		trb_type == TRB_NORMAL) {
+		td->request_length_set = true;
+		td->priv_request->request.actual = requested - remaining;
+	}
+
+	/* at status stage */
+	if (!td->request_length_set)
+		td->priv_request->request.actual = requested;
+
+	if (usbssp_data->ep0state == USBSSP_EP0_DATA_PHASE
+	   && ep_priv->number == 0
+	   && usbssp_data->three_stage_setup) {
+
+		td = list_entry(ep_ring->td_list.next,
+			struct usbssp_td, td_list);
+		usbssp_data->ep0state = USBSSP_EP0_STATUS_PHASE;
+		usbssp_dbg(usbssp_data, "Arm Status stage\n");
+		giveback_first_trb(usbssp_data, ep_index, 0,
+			ep_ring->cycle_state, &td->last_trb->generic);
+		return 0;
+	}
+finish_td:
+	return finish_td(usbssp_data, td, event, ep_priv, status);
+}
+
+/*
+ * Process isochronous tds, update usb request status and actual_length.
+ */
+static int process_isoc_td(struct usbssp_udc *usbssp_data, struct usbssp_td *td,
+	union usbssp_trb *ep_trb, struct usbssp_transfer_event *event,
+	struct usbssp_ep *ep_priv, int *status)
+{
+	struct usbssp_ring *ep_ring;
+	struct usbssp_request *req_priv;
+	int idx;
+	u32 trb_comp_code;
+	u32 remaining, requested, ep_trb_len;
+	bool sum_trbs_for_length = false;
+	int short_framestatus;
+
+	ep_ring = usbssp_dma_to_transfer_ring(ep_priv,
+			le64_to_cpu(event->buffer));
+	trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
+	req_priv = td->priv_request;
+	idx = req_priv->num_tds;
+	requested = req_priv->request.length;
+	remaining = EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
+	ep_trb_len = TRB_LEN(le32_to_cpu(ep_trb->generic.field[2]));
+	short_framestatus = req_priv->request.short_not_ok ?
+			-EREMOTEIO : 0;
+
+	/* handle completion code */
+	switch (trb_comp_code) {
+	case COMP_SUCCESS:
+		if (remaining) {
+			req_priv->request.status = short_framestatus;
+			break;
+		}
+		req_priv->request.status = 0;
+		break;
+	case COMP_SHORT_PACKET:
+		req_priv->request.status = short_framestatus;
+		sum_trbs_for_length = true;
+		break;
+	case COMP_ISOCH_BUFFER_OVERRUN:
+	case COMP_BABBLE_DETECTED_ERROR:
+		req_priv->request.status = -EOVERFLOW;
+		break;
+	case COMP_USB_TRANSACTION_ERROR:
+		req_priv->request.status = -EPROTO;
+		if (ep_trb != td->last_trb)
+			return 0;
+		break;
+	case COMP_STOPPED:
+		sum_trbs_for_length = true;
+		break;
+	case COMP_STOPPED_SHORT_PACKET:
+		/* field normally containing residue now contains tranferred */
+		req_priv->request.status  = short_framestatus;
+		requested = remaining;
+		break;
+	case COMP_STOPPED_LENGTH_INVALID:
+		requested = 0;
+		remaining = 0;
+		break;
+	default:
+		sum_trbs_for_length = true;
+		req_priv->request.status = -1;
+		break;
+	}
+
+	/*Fixme*/
+#if 0
+	if (sum_trbs_for_length)
+		req_priv->request.actual = sum_trb_lengths(usbssp_data,
+				ep_ring, ep_trb) +
+				ep_trb_len - remaining;
+	else
+		req_priv->request.actual = requested;
+
+	td->req_priv->request.actual += frame->actual_length;
+#endif
+	return finish_td(usbssp_data, td, event, ep_priv, status);
+}
+
+static int skip_isoc_td(struct usbssp_udc *usbssp_data,
+			struct usbssp_td *td,
+			struct usbssp_transfer_event *event,
+			struct usbssp_ep *ep_priv,
+			int *status)
+{
+	struct usbssp_ring *ep_ring;
+	struct usbssp_request *req_priv;
+	//struct usb_iso_packet_descriptor *frame;
+	int idx;
+
+	ep_ring = usbssp_dma_to_transfer_ring(ep_priv,
+			le64_to_cpu(event->buffer));
+	req_priv = td->priv_request/*->hcpriv*/;
+	idx = req_priv->num_tds;
+	//TODO
+//	frame = &td->priv_request->iso_frame_desc[idx];
+
+	/* The transfer is partly done. */
+//	frame->status = -EXDEV;
+
+	/* calc actual length */
+//	frame->actual_length = 0;
+
+	/* Update ring dequeue pointer */
+	while (ep_ring->dequeue != td->last_trb)
+		inc_deq(usbssp_data, ep_ring);
+	inc_deq(usbssp_data, ep_ring);
+
+	return finish_td(usbssp_data, td, event, ep_priv, status);
+}
+
+/*
+ * Process bulk and interrupt tds, update usb request status and actual_length.
+ */
+static int process_bulk_intr_td(struct usbssp_udc *usbssp_data,
+				struct usbssp_td *td,
+				union usbssp_trb *ep_trb,
+				struct usbssp_transfer_event *event,
+				struct usbssp_ep *ep, int *status)
+{
+	struct usbssp_ring *ep_ring;
+	u32 trb_comp_code;
+	u32 remaining, requested, ep_trb_len;
+
+	ep_ring = usbssp_dma_to_transfer_ring(ep, le64_to_cpu(event->buffer));
+	trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
+	remaining = EVENT_TRB_LEN(le32_to_cpu(event->transfer_len));
+	ep_trb_len = TRB_LEN(le32_to_cpu(ep_trb->generic.field[2]));
+	requested = td->priv_request->request.length;
+
+	switch (trb_comp_code) {
+	case COMP_SUCCESS:
+		/* handle success with untransferred data as short packet */
+		if (ep_trb != td->last_trb || remaining) {
+			usbssp_warn(usbssp_data, "WARN Successful completion "
+					"on short TX\n");
+			usbssp_dbg(usbssp_data,
+				"ep %#x - asked for %d bytes, %d bytes untransferred\n",
+				td->priv_request->dep->endpoint.desc->bEndpointAddress,
+				requested, remaining);
+		}
+		*status = 0;
+		break;
+	case COMP_SHORT_PACKET:
+		usbssp_dbg(usbssp_data,
+			"ep %#x - asked for %d bytes, %d bytes untransferred\n",
+			 td->priv_request->dep->endpoint.desc->bEndpointAddress,
+			 requested, remaining);
+
+		*status = 0;
+		break;
+	case COMP_STOPPED_SHORT_PACKET:
+		td->priv_request->request.length = remaining;
+		goto finish_td;
+	case COMP_STOPPED_LENGTH_INVALID:
+		/* stopped on ep trb with invalid length, exclude it */
+		ep_trb_len	= 0;
+		remaining	= 0;
+		break;
+	default:
+		/* Others already handled above */
+		break;
+	}
+
+	if (ep_trb == td->last_trb)
+		td->priv_request->request.actual = requested - remaining;
+	else
+		td->priv_request->request.actual =
+			sum_trb_lengths(usbssp_data, ep_ring, ep_trb) +
+			ep_trb_len - remaining;
+finish_td:
+	if (remaining > requested) {
+		usbssp_warn(usbssp_data,
+			"bad transfer trb length %d in event trb\n",
+			remaining);
+		td->priv_request->request.actual = 0;
+	}
+
+	return finish_td(usbssp_data, td, event, ep, status);
+}
+
+/*
+ * If this function returns an error condition, it means it got a Transfer
+ * event with a corrupted Slot ID, Endpoint ID, or TRB DMA address.
+ * At this point, the USBSSP controller is probably hosed and should be reset.
+ */
+static int handle_tx_event(struct usbssp_udc *usbssp_data,
+			   struct usbssp_transfer_event *event)
+{
+	struct usbssp_device *dev_priv;
+	struct usbssp_ep *ep_priv;
+	struct usbssp_ring *ep_ring;
+	unsigned int slot_id;
+	int ep_index;
+	struct usbssp_td *td = NULL;
+	dma_addr_t ep_trb_dma;
+	struct usbssp_segment *ep_seg;
+	union usbssp_trb *ep_trb;
+	int status = -EINPROGRESS;
+	struct usbssp_ep_ctx *ep_ctx;
+	struct list_head *tmp;
+	u32 trb_comp_code;
+	int ret = 0;
+	int td_num = 0;
+	bool handling_skipped_tds = false;
+	const struct usb_endpoint_descriptor *desc;
+
+	slot_id = TRB_TO_SLOT_ID(le32_to_cpu(event->flags));
+	ep_index = TRB_TO_EP_ID(le32_to_cpu(event->flags)) - 1;
+	trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->transfer_len));
+	ep_trb_dma = le64_to_cpu(event->buffer);
+
+	dev_priv = &usbssp_data->devs;
+
+	ep_priv = &dev_priv->eps[ep_index];
+	ep_ring = usbssp_dma_to_transfer_ring(ep_priv,
+			le64_to_cpu(event->buffer));
+	ep_ctx = usbssp_get_ep_ctx(usbssp_data, dev_priv->out_ctx, ep_index);
+
+	if (GET_EP_CTX_STATE(ep_ctx) == EP_STATE_DISABLED) {
+		usbssp_err(usbssp_data,
+			 "ERROR Transfer event for disabled endpoint slot %u ep %u\n",
+			  slot_id, ep_index);
+		goto err_out;
+	}
+
+	/* Some transfer events don't always point to a trb*/
+	if (!ep_ring) {
+		switch (trb_comp_code) {
+		case COMP_USB_TRANSACTION_ERROR:
+		case COMP_INVALID_STREAM_TYPE_ERROR:
+		case COMP_INVALID_STREAM_ID_ERROR:
+			goto cleanup;
+		case COMP_RING_UNDERRUN:
+		case COMP_RING_OVERRUN:
+			goto cleanup;
+		default:
+			usbssp_err(usbssp_data, "ERROR Transfer event for "
+				"unknown stream ring slot %u ep %u\n",
+				 slot_id, ep_index);
+			goto err_out;
+		}
+	}
+
+	/* Count current td numbers if ep->skip is set */
+	if (ep_priv->skip) {
+		list_for_each(tmp, &ep_ring->td_list)
+			td_num++;
+	}
+
+	/* Look for common error cases */
+	switch (trb_comp_code) {
+	/* Skip codes that require special handling depending on
+	 * transfer type
+	 */
+	case COMP_SUCCESS:
+		if (EVENT_TRB_LEN(le32_to_cpu(event->transfer_len)) == 0)
+			break;
+
+		usbssp_warn_ratelimited(usbssp_data,
+			"WARN Successful completion on short TX\n");
+	case COMP_SHORT_PACKET:
+		break;
+	case COMP_STOPPED:
+		usbssp_dbg(usbssp_data, "Stopped on Transfer TRB for ep %u\n",
+			ep_index);
+		break;
+	case COMP_STOPPED_LENGTH_INVALID:
+		usbssp_dbg(usbssp_data,
+			"Stopped on No-op or Link TRB for ep %u\n",
+			ep_index);
+		break;
+	case COMP_STOPPED_SHORT_PACKET:
+		usbssp_dbg(usbssp_data,
+			"Stopped with short packet transfer detected for ep %u\n",
+			ep_index);
+		usbssp_dbg_ctx(usbssp_data, usbssp_data->devs.out_ctx, 2);
+		break;
+	case COMP_BABBLE_DETECTED_ERROR:
+		usbssp_dbg(usbssp_data, "Babble error for ep %u on endpoint\n",
+			ep_index);
+		status = -EOVERFLOW;
+		break;
+	case COMP_TRB_ERROR:
+		usbssp_warn(usbssp_data, "WARN: TRB error on endpoint %u\n",
+			ep_index);
+		status = -EILSEQ;
+		break;
+	/* completion codes not indicating endpoint state change */
+	case COMP_DATA_BUFFER_ERROR:
+		usbssp_warn(usbssp_data,
+			"WARN: USBSSP couldn't access mem fast enough for ep %u\n",
+			ep_index);
+		status = -ENOSR;
+		break;
+	case COMP_ISOCH_BUFFER_OVERRUN:
+		usbssp_warn(usbssp_data,
+			"WARN: buffer overrun event for ep %u on endpoint",
+			ep_index);
+		break;
+	case COMP_RING_UNDERRUN:
+		/*
+		 * When the Isoch ring is empty, the DC will generate
+		 * a Ring Overrun Event for IN Isoch endpoint or Ring
+		 * Underrun Event for OUT Isoch endpoint.
+		 */
+		usbssp_dbg(usbssp_data, "underrun event on endpoint\n");
+		if (!list_empty(&ep_ring->td_list))
+			usbssp_dbg(usbssp_data, "Underrun Event for ep %d "
+				"still with TDs queued?\n", ep_index);
+		goto cleanup;
+	case COMP_RING_OVERRUN:
+		usbssp_dbg(usbssp_data, "overrun event on endpoint\n");
+		if (!list_empty(&ep_ring->td_list))
+			usbssp_dbg(usbssp_data, "Overrun Event for ep %d "
+				"still with TDs queued?\n",
+				ep_index);
+		goto cleanup;
+	case COMP_MISSED_SERVICE_ERROR:
+		/*
+		 * When encounter missed service error, one or more isoc tds
+		 * may be missed by DC.
+		 * Set skip flag of the ep_ring; Complete the missed tds as
+		 * short transfer when process the ep_ring next time.
+		 */
+		ep_priv->skip = true;
+		usbssp_dbg(usbssp_data,
+			"Miss service interval error for ep %u, set skip flag\n",
+			ep_index);
+		goto cleanup;
+	case COMP_INCOMPATIBLE_DEVICE_ERROR:
+		/* needs disable slot command to recover */
+		usbssp_warn(usbssp_data,
+			"WARN: detect an incompatible device for ep %u",
+			ep_index);
+		status = -EPROTO;
+		break;
+	default:
+		if (usbssp_is_vendor_info_code(usbssp_data, trb_comp_code)) {
+			status = 0;
+			break;
+		}
+		usbssp_warn(usbssp_data,
+			"ERROR Unknown event condition %u, for ep %u - USBSSP probably busted\n",
+			trb_comp_code, ep_index);
+		goto cleanup;
+	}
+
+	do {
+		/* This TRB should be in the TD at the head of this ring's
+		 * TD list.
+		 */
+		if (list_empty(&ep_ring->td_list)) {
+			/*
+			 * Don't print wanings if it's due to a stopped endpoint
+			 * generating an extra completion event if the device
+			 * was suspended. Or, a event for the last TRB of a
+			 * short TD we already got a short event for.
+			 * The short TD is already removed from the TD list.
+			 */
+			if (!(trb_comp_code == COMP_STOPPED ||
+			    trb_comp_code == COMP_STOPPED_LENGTH_INVALID  ||
+			    ep_ring->last_td_was_short)) {
+				usbssp_warn(usbssp_data,
+					"WARN Event TRB for ep %d with no TDs queued?\n",
+					ep_index);
+			}
+
+			if (ep_priv->skip) {
+				ep_priv->skip = false;
+				usbssp_dbg(usbssp_data,
+					"td_list is empty while skip "
+					"flag set. Clear skip flag for ep %u.\n",
+					ep_index);
+			}
+			goto cleanup;
+		}
+
+		/* We've skipped all the TDs on the ep ring when ep->skip set */
+		if (ep_priv->skip && td_num == 0) {
+			ep_priv->skip = false;
+			usbssp_dbg(usbssp_data,
+				"All tds on the ep_ring skipped. "
+				"Clear skip flag for ep %u.\n", ep_index);
+			goto cleanup;
+		}
+
+		td = list_entry(ep_ring->td_list.next, struct usbssp_td,
+				td_list);
+
+		if (ep_priv->skip)
+			td_num--;
+
+		/* Is this a TRB in the currently executing TD? */
+		ep_seg = usbssp_trb_in_td(usbssp_data, ep_ring->deq_seg,
+				ep_ring->dequeue, td->last_trb,
+				ep_trb_dma, false);
+
+		/*
+		 * Skip the Force Stopped Event. The event_trb(ep_trb_dma)
+		 * of FSE is not in the current TD pointed by ep_ring->dequeue
+		 * because that the hardware dequeue pointer still at the
+		 * previous TRB of the current TD. The previous TRB maybe a
+		 * Link TD or the last TRB of the previous TD. The command
+		 * completion handle will take care the rest.
+		 */
+		if (!ep_seg && (trb_comp_code == COMP_STOPPED ||
+		     trb_comp_code == COMP_STOPPED_LENGTH_INVALID)) {
+			goto cleanup;
+		}
+
+		desc = td->priv_request->dep->endpoint.desc;
+		if (!ep_seg) {
+			if (!ep_priv->skip || !usb_endpoint_xfer_isoc(desc)) {
+
+				/* USBSSP is busted, give up! */
+				usbssp_err(usbssp_data,
+					"ERROR Transfer event TRB DMA ptr not "
+					"part of current TD ep_index %d "
+					"comp_code %u\n", ep_index,
+					trb_comp_code);
+				usbssp_trb_in_td(usbssp_data, ep_ring->deq_seg,
+					ep_ring->dequeue, td->last_trb,
+					ep_trb_dma, true);
+				return -ESHUTDOWN;
+			}
+
+			ret = skip_isoc_td(usbssp_data, td, event, ep_priv,
+					&status);
+			goto cleanup;
+		}
+
+		if (trb_comp_code == COMP_SHORT_PACKET)
+			ep_ring->last_td_was_short = true;
+		else
+			ep_ring->last_td_was_short = false;
+
+		if (ep_priv->skip) {
+			usbssp_dbg(usbssp_data,
+				"Found td. Clear skip flag for ep %u.\n",
+				ep_index);
+			ep_priv->skip = false;
+		}
+
+		ep_trb = &ep_seg->trbs[(ep_trb_dma - ep_seg->dma) / sizeof(*ep_trb)];
+
+		trace_usbssp_handle_transfer(ep_ring,
+				(struct usbssp_generic_trb *) ep_trb);
+
+		if (trb_is_noop(ep_trb)) {
+			usbssp_dbg(usbssp_data,
+				"event_trb is a no-op TRB. Skip it\n");
+			goto cleanup;
+		}
+
+		if (usb_endpoint_xfer_control(desc)) {
+			ret = process_ctrl_td(usbssp_data, td, ep_trb, event,
+				ep_priv, &status);
+		} else if (usb_endpoint_xfer_isoc(desc)) {
+			ret = process_isoc_td(usbssp_data, td, ep_trb,
+				event, ep_priv, &status);
+		} else {
+			ret = process_bulk_intr_td(usbssp_data, td, ep_trb,
+				event, ep_priv, &status);
+		}
+cleanup:
+		handling_skipped_tds = ep_priv->skip &&
+			trb_comp_code != COMP_MISSED_SERVICE_ERROR;
+
+		/*
+		 * Do not update event ring dequeue pointer if we're in a loop
+		 * processing missed tds.
+		 */
+		if (!handling_skipped_tds)
+			inc_deq(usbssp_data, usbssp_data->event_ring);
+	/*
+	 * If ep->skip is set, it means there are missed tds on the
+	 * endpoint ring need to take care of.
+	 * Process them as short transfer until reach the td pointed by
+	 * the event.
+	 */
+	} while (handling_skipped_tds);
+
+	return 0;
+
+err_out:
+	usbssp_err(usbssp_data, "@%016llx %08x %08x %08x %08x\n",
+		 (unsigned long long) usbssp_trb_virt_to_dma(
+			 usbssp_data->event_ring->deq_seg,
+			 usbssp_data->event_ring->dequeue),
+		 lower_32_bits(le64_to_cpu(event->buffer)),
+		 upper_32_bits(le64_to_cpu(event->buffer)),
+		 le32_to_cpu(event->transfer_len),
+		 le32_to_cpu(event->flags));
+	return -ENODEV;
+}
+
+/*
+ * This function handles all events on the event ring.
+ * Function can defers handling of some events to kernel thread.
+ * Returns >0 for "possibly more events to process" (caller should call again),
+ * otherwise 0 if done.  In future, <0 returns should indicate error code.
+ */
+int usbssp_handle_event(struct usbssp_udc *usbssp_data)
+{
+	union usbssp_trb *event;
+	int update_ptrs = 1;
+	int ret = 0;
+	__le32 cycle_bit;
+
+	unsigned int trb_comp_code;
+
+	if (!usbssp_data->event_ring || !usbssp_data->event_ring->dequeue) {
+		usbssp_err(usbssp_data, "ERROR event ring not ready\n");
+		return -ENOMEM;
+	}
+
+	event = usbssp_data->event_ring->dequeue;
+
+	cycle_bit = (le32_to_cpu(event->event_cmd.flags) & TRB_CYCLE);
+	/* Does the USBSSP or Driver own the TRB? */
+	if (cycle_bit != usbssp_data->event_ring->cycle_state)
+		return 0;
+
+	trace_usbssp_handle_event(usbssp_data->event_ring, &event->generic);
+
+	/*
+	 * Barrier between reading the TRB_CYCLE (valid) flag above and any
+	 * speculative reads of the event's flags/data below.
+	 */
+	rmb();
+
+	switch ((le32_to_cpu(event->event_cmd.flags) & TRB_TYPE_BITMASK)) {
+	case TRB_TYPE(TRB_COMPLETION):
+		handle_cmd_completion(usbssp_data, &event->event_cmd);
+		break;
+	case TRB_TYPE(TRB_PORT_STATUS):
+		handle_port_status(usbssp_data, event);
+		update_ptrs = 0;
+		break;
+	case TRB_TYPE(TRB_TRANSFER):
+		ret = handle_tx_event(usbssp_data, &event->trans_event);
+
+		if (ret >= 0)
+			update_ptrs = 0;
+		break;
+	case TRB_TYPE(TRB_SETUP): {
+		/*handling of SETUP packet are deferred to thread. */
+
+		usbssp_data->ep0state = USBSSP_EP0_SETUP_PHASE;
+		usbssp_data->setupId = TRB_SETUPID_TO_TYPE(event->trans_event.flags);
+		usbssp_data->setup_speed = TRB_SETUP_SPEEDID(event->trans_event.flags);
+
+		/*save current setup packet. It some case it will be used
+		 * latter
+		 */
+		usbssp_data->setup = *((struct usb_ctrlrequest  *)&event->trans_event.buffer);
+
+		usbssp_dbg(usbssp_data,
+			"Setup packet (id: %d) defered to thread\n",
+			usbssp_data->setupId);
+
+		usbssp_data->defered_event |= EVENT_SETUP_PACKET;
+		queue_work(usbssp_data->bottom_irq_wq,
+				&usbssp_data->bottom_irq);
+		break;
+	}
+
+	case TRB_TYPE(TRB_HC_EVENT):
+		trb_comp_code = GET_COMP_CODE(le32_to_cpu(event->generic.field[2]));
+		usbssp_warn(usbssp_data,
+			"Host Controller Error detected with error code 0x%02x\n",
+			trb_comp_code);
+		/* Look for common error cases */
+		switch (trb_comp_code) {
+		case COMP_EVENT_RING_FULL_ERROR:
+			usbssp_dbg(usbssp_data,
+				"Error: Event Ring Full\n");
+			break;
+		default:
+			usbssp_dbg(usbssp_data,
+				"Not supported completion code\n");
+		}
+		break;
+	default:
+		if ((le32_to_cpu(event->event_cmd.flags) & TRB_TYPE_BITMASK) >=
+		    TRB_TYPE(48))
+			handle_vendor_event(usbssp_data, event);
+		else
+			usbssp_warn(usbssp_data, "ERROR unknown event type %d\n",
+				TRB_FIELD_TO_TYPE(
+				le32_to_cpu(event->event_cmd.flags)));
+	}
+
+
+	/* Any of the above functions may drop and re-acquire the lock, so check
+	 * to make sure a watchdog timer didn't mark the device as
+	 * non-responsive.
+	 */
+	if (usbssp_data->usbssp_state & USBSSP_STATE_DYING) {
+		usbssp_dbg(usbssp_data, "USBSSP device dying, returning from "
+			"event handle.\n");
+		return 0;
+	}
+
+	if (update_ptrs) {
+		/* Update SW event ring dequeue pointer */
+		inc_deq(usbssp_data, usbssp_data->event_ring);
+	}
+
+	/* Are there more items on the event ring?  Caller will call us again to
+	 * check.
+	 */
+	return 1;
+}
+
+
+irqreturn_t usbssp_irq(int irq, void *priv)
+{
+	struct usbssp_udc *usbssp_data = (struct usbssp_udc *)priv;
+	union usbssp_trb *event_ring_deq;
+	irqreturn_t ret = IRQ_NONE;
+	unsigned long flags;
+	dma_addr_t deq;
+	u64 temp_64;
+	u32 status;
+
+	spin_lock_irqsave(&usbssp_data->lock, flags);
+
+	/* Check if the USBSSP controller generated the interrupt,
+	 * or the irq is shared
+	 */
+	status = readl(&usbssp_data->op_regs->status);
+	if (status == ~(u32)0) {
+		usbssp_udc_died(usbssp_data);
+		ret = IRQ_HANDLED;
+		goto out;
+	}
+
+	if (!(status & STS_EINT))
+		goto out;
+
+	if (status & STS_FATAL) {
+		usbssp_warn(usbssp_data, "WARNING: Device Controller Error\n");
+		usbssp_halt(usbssp_data);
+		ret = IRQ_HANDLED;
+		goto out;
+	}
+
+	/*
+	 * Clear the op reg interrupt status first,
+	 * so we can receive interrupts from other MSI-X interrupters.
+	 * Write 1 to clear the interrupt status.
+	 */
+	status |= STS_EINT;
+	writel(status, &usbssp_data->op_regs->status);
+
+	if (usbssp_data->msi_enabled) {
+		u32 irq_pending;
+
+		irq_pending = readl(&usbssp_data->ir_set->irq_pending);
+		irq_pending |= IMAN_IP;
+		writel(irq_pending, &usbssp_data->ir_set->irq_pending);
+	}
+
+	if (usbssp_data->usbssp_state & USBSSP_STATE_DYING ||
+			usbssp_data->usbssp_state & USBSSP_STATE_HALTED) {
+		usbssp_dbg(usbssp_data,
+				"USBSSP controller dying, ignoring interrupt. "
+				"Shouldn't IRQs be disabled?\n");
+		/* Clear the event handler busy flag (RW1C);
+		 * the event ring should be empty.
+		 */
+		temp_64 = usbssp_read_64(usbssp_data,
+				&usbssp_data->ir_set->erst_dequeue);
+		usbssp_write_64(usbssp_data, temp_64 | ERST_EHB,
+				&usbssp_data->ir_set->erst_dequeue);
+		ret = IRQ_HANDLED;
+		goto out;
+	}
+
+	event_ring_deq = usbssp_data->event_ring->dequeue;
+
+	while ((ret = usbssp_handle_event(usbssp_data)) == 1) {
+	}
+
+	temp_64 = usbssp_read_64(usbssp_data,
+			&usbssp_data->ir_set->erst_dequeue);
+	/* If necessary, update the HW's version of the event ring deq ptr. */
+	if (event_ring_deq != usbssp_data->event_ring->dequeue) {
+
+		deq = usbssp_trb_virt_to_dma(usbssp_data->event_ring->deq_seg,
+				usbssp_data->event_ring->dequeue);
+
+		if (deq == 0)
+			usbssp_warn(usbssp_data,
+					"WARN something wrong with SW event "
+					"ring dequeue ptr.\n");
+		/* Update USBSSP event ring dequeue pointer */
+		temp_64 &= ERST_PTR_MASK;
+		temp_64 |= ((u64) deq & (u64) ~ERST_PTR_MASK);
+	}
+
+	/* Clear the event handler busy flag (RW1C); event ring is empty. */
+	temp_64 |= ERST_EHB;
+	usbssp_write_64(usbssp_data, temp_64,
+			&usbssp_data->ir_set->erst_dequeue);
+	ret = IRQ_HANDLED;
+
+out:
+	spin_unlock_irqrestore(&usbssp_data->lock, flags);
+	return ret;
+}
+
+irqreturn_t usbssp_msi_irq(int irq, void *usbssp_data)
+{
+	return usbssp_irq(irq, usbssp_data);
+}
+
+/****		Endpoint Ring Operations	****/
+
+/*
+ * Generic function for queueing a TRB on a ring.
+ * The caller must have checked to make sure there's room on the ring.
+ *
+ * @more_trbs_coming:	Will you enqueue more TRBs before calling
+ *			prepare_transfer()?
+ */
+static void queue_trb(struct usbssp_udc *usbssp_data, struct usbssp_ring *ring,
+		bool more_trbs_coming,
+		u32 field1, u32 field2, u32 field3, u32 field4)
+{
+	struct usbssp_generic_trb *trb;
+
+	trb = &ring->enqueue->generic;
+
+	usbssp_dbg(usbssp_data, "Queue TRB at virt: %p, dma: %llx\n", trb,
+			usbssp_trb_virt_to_dma(ring->enq_seg, ring->enqueue));
+
+	trb->field[0] = cpu_to_le32(field1);
+	trb->field[1] = cpu_to_le32(field2);
+	trb->field[2] = cpu_to_le32(field3);
+	trb->field[3] = cpu_to_le32(field4);
+
+	trace_usbssp_queue_trb(ring, trb);
+	inc_enq(usbssp_data, ring, more_trbs_coming);
+}
+
+/*
+ * Does various checks on the endpoint ring, and makes it ready to
+ * queue num_trbs.
+ */
+static int prepare_ring(struct usbssp_udc *usbssp_data,
+			struct usbssp_ring *ep_ring,
+			u32 ep_state, unsigned
+			int num_trbs,
+			gfp_t mem_flags)
+{
+	unsigned int num_trbs_needed;
+
+	/* Make sure the endpoint has been added to USBSSP schedule */
+	switch (ep_state) {
+	case EP_STATE_DISABLED:
+		usbssp_warn(usbssp_data,
+			"WARN request submitted to disabled ep\n");
+		return -ENOENT;
+	case EP_STATE_ERROR:
+		usbssp_warn(usbssp_data,
+			"WARN waiting for error on ep to be cleared\n");
+		return -EINVAL;
+	case EP_STATE_HALTED:
+		usbssp_dbg(usbssp_data,
+			"WARN halted endpoint, queueing request anyway.\n");
+	case EP_STATE_STOPPED:
+	case EP_STATE_RUNNING:
+		break;
+	default:
+		usbssp_err(usbssp_data,
+			"ERROR unknown endpoint state for ep\n");
+		return -EINVAL;
+	}
+
+	while (1) {
+		if (room_on_ring(usbssp_data, ep_ring, num_trbs))
+			break;
+
+		if (ep_ring == usbssp_data->cmd_ring) {
+			usbssp_err(usbssp_data,
+				"Do not support expand command ring\n");
+			return -ENOMEM;
+		}
+
+		usbssp_dbg_trace(usbssp_data, trace_usbssp_dbg_ring_expansion,
+				"ERROR no room on ep ring, try ring expansion");
+
+		num_trbs_needed = num_trbs - ep_ring->num_trbs_free;
+		if (usbssp_ring_expansion(usbssp_data, ep_ring, num_trbs_needed,
+					mem_flags)) {
+			usbssp_err(usbssp_data, "Ring expansion failed\n");
+			return -ENOMEM;
+		}
+	}
+
+	while (trb_is_link(ep_ring->enqueue)) {
+
+		ep_ring->enqueue->link.control |= cpu_to_le32(TRB_CHAIN);
+		wmb();
+		ep_ring->enqueue->link.control ^= cpu_to_le32(TRB_CYCLE);
+
+		/* Toggle the cycle bit after the last ring segment. */
+		if (link_trb_toggles_cycle(ep_ring->enqueue))
+			ep_ring->cycle_state ^= 1;
+		ep_ring->enq_seg = ep_ring->enq_seg->next;
+		ep_ring->enqueue = ep_ring->enq_seg->trbs;
+	}
+	return 0;
+}
+
+static int prepare_transfer(struct usbssp_udc *usbssp_data,
+		struct usbssp_device *dev_priv,
+		unsigned int ep_index,
+		unsigned int stream_id,
+		unsigned int num_trbs,
+		struct usbssp_request *req_priv,
+		unsigned int td_index,
+		gfp_t mem_flags)
+{
+	int ret;
+	struct usbssp_td	*td;
+	struct usbssp_ring *ep_ring;
+	struct usbssp_ep_ctx *ep_ctx = usbssp_get_ep_ctx(usbssp_data,
+					dev_priv->out_ctx, ep_index);
+
+	ep_ring = usbssp_stream_id_to_ring(dev_priv, ep_index, stream_id);
+
+	if (!ep_ring) {
+		usbssp_dbg(usbssp_data,
+				"Can't prepare ring for bad stream ID %u\n",
+				stream_id);
+		return -EINVAL;
+	}
+
+	ret = prepare_ring(usbssp_data, ep_ring, GET_EP_CTX_STATE(ep_ctx),
+			num_trbs, mem_flags);
+
+	if (ret)
+		return ret;
+
+	td = &req_priv->td[td_index];
+	INIT_LIST_HEAD(&td->td_list);
+
+	td->priv_request = req_priv;
+	/* Add this TD to the tail of the endpoint ring's TD list */
+	list_add_tail(&td->td_list, &ep_ring->td_list);
+	td->start_seg = ep_ring->enq_seg;
+	td->first_trb = ep_ring->enqueue;
+
+	return 0;
+}
+
+unsigned int count_trbs(u64 addr, u64 len)
+{
+	unsigned int num_trbs;
+
+	num_trbs = DIV_ROUND_UP(len + (addr & (TRB_MAX_BUFF_SIZE - 1)),
+			TRB_MAX_BUFF_SIZE);
+	if (num_trbs == 0)
+		num_trbs++;
+
+	return num_trbs;
+}
+
+static inline unsigned int count_trbs_needed(struct usbssp_request *req_priv)
+{
+	return count_trbs(req_priv->request.dma, req_priv->request.length);
+}
+
+static unsigned int count_sg_trbs_needed(struct usbssp_request *req_priv)
+{
+	struct scatterlist *sg;
+	unsigned int i, len, full_len, num_trbs = 0;
+
+	full_len = req_priv->request.length;
+
+	for_each_sg(req_priv->sg, sg, req_priv->num_pending_sgs, i) {
+		len = sg_dma_len(sg);
+		num_trbs += count_trbs(sg_dma_address(sg), len);
+		len = min_t(unsigned int, len, full_len);
+		full_len -= len;
+		if (full_len == 0)
+			break;
+	}
+
+	return num_trbs;
+}
+
+static unsigned int count_isoc_trbs_needed(struct usbssp_request *req_priv)
+{
+	u64 addr, len;
+
+	addr = (u64) req_priv->request.dma;
+	len = req_priv->request.length;
+
+	return count_trbs(addr, len);
+}
+
+static void check_trb_math(struct usbssp_request *req_priv, int running_total)
+{
+	if (unlikely(running_total != req_priv->request.length))
+		dev_err(req_priv->dep->usbssp_data->dev,
+				"%s - ep %#x - Miscalculated tx length, "
+				"queued %#x (%d), asked for %#x (%d)\n",
+				__func__,
+				req_priv->dep->endpoint.desc->bEndpointAddress,
+				running_total, running_total,
+				req_priv->request.length,
+				req_priv->request.length);
+}
+
+static void giveback_first_trb(struct usbssp_udc *usbssp_data,
+			       unsigned int ep_index,
+			       unsigned int stream_id,
+			       int start_cycle,
+			       struct usbssp_generic_trb *start_trb)
+{
+	/*
+	 * Pass all the TRBs to the hardware at once and make sure this write
+	 * isn't reordered.
+	 */
+	wmb();
+	if (start_cycle)
+		start_trb->field[3] |= cpu_to_le32(start_cycle);
+	else
+		start_trb->field[3] &= cpu_to_le32(~TRB_CYCLE);
+
+	usbssp_dbg_ep_rings(usbssp_data, ep_index,
+			&usbssp_data->devs.eps[ep_index]);
+	usbssp_ring_ep_doorbell(usbssp_data,  ep_index, stream_id);
+}
+
+/*
+ * USBSSP uses normal TRBs for both bulk and interrupt.  When the interrupt
+ * endpoint is to be serviced, the DC will consume (at most) one TD.  A TD
+ * (comprised of sg list entries) can take several service intervals to
+ * transmit.
+ */
+int usbssp_queue_intr_tx(struct usbssp_udc *usbssp_data, gfp_t mem_flags,
+		struct usbssp_request *req_priv, unsigned int ep_index)
+{
+	struct usbssp_ep_ctx *ep_ctx;
+
+	ep_ctx = usbssp_get_ep_ctx(usbssp_data, usbssp_data->devs.out_ctx,
+			ep_index);
+
+	return usbssp_queue_bulk_tx(usbssp_data, mem_flags, req_priv, ep_index);
+}
+
+/*
+ * For USBSSP controllers, TD size is the number of max packet sized
+ * packets remaining in the TD (*not* including this TRB).
+ *
+ * Total TD packet count = total_packet_count =
+ *     DIV_ROUND_UP(TD size in bytes / wMaxPacketSize)
+ *
+ * Packets transferred up to and including this TRB = packets_transferred =
+ *     rounddown(total bytes transferred including this TRB / wMaxPacketSize)
+ *
+ * TD size = total_packet_count - packets_transferred
+ *
+ * For USBSSP it must fit in bits 21:17, so it can't be bigger than 31.
+ * This is taken care of in the TRB_TD_SIZE() macro
+ *
+ * The last TRB in a TD must have the TD size set to zero.
+ */
+static u32 usbssp_td_remainder(struct usbssp_udc *usbssp_data,
+			       int transferred,
+			       int trb_buff_len,
+			       unsigned int td_total_len,
+			       struct usbssp_request *req_priv,
+			       bool more_trbs_coming)
+{
+	u32 maxp, total_packet_count;
+
+	/* One TRB with a zero-length data packet. */
+	if (!more_trbs_coming || (transferred == 0 && trb_buff_len == 0) ||
+	    trb_buff_len == td_total_len)
+		return 0;
+
+	maxp = usb_endpoint_maxp(req_priv->dep->endpoint.desc);
+	total_packet_count = DIV_ROUND_UP(td_total_len, maxp);
+
+	/* Queuing functions don't count the current TRB into transferred */
+	return (total_packet_count - ((transferred + trb_buff_len) / maxp));
+}
+
+static int usbssp_align_td(struct usbssp_udc *usbssp_data,
+		     struct usbssp_request *req_priv, u32 enqd_len,
+			 u32 *trb_buff_len, struct usbssp_segment *seg)
+{
+	struct device *dev = usbssp_data->dev;
+	unsigned int unalign;
+	unsigned int max_pkt;
+	u32 new_buff_len;
+
+	max_pkt = GET_MAX_PACKET(
+			usb_endpoint_maxp(req_priv->dep->endpoint.desc));
+	unalign = (enqd_len + *trb_buff_len) % max_pkt;
+
+	/* we got lucky, last normal TRB data on segment is packet aligned */
+	if (unalign == 0)
+		return 0;
+
+	usbssp_dbg(usbssp_data, "Unaligned %d bytes, buff len %d\n",
+		 unalign, *trb_buff_len);
+
+	/* is the last nornal TRB alignable by splitting it */
+	if (*trb_buff_len > unalign) {
+		*trb_buff_len -= unalign;
+		usbssp_dbg(usbssp_data, "split align, new buff len %d\n",
+				*trb_buff_len);
+		return 0;
+	}
+
+	/*
+	 * We want enqd_len + trb_buff_len to sum up to a number aligned to
+	 * number which is divisible by the endpoint's wMaxPacketSize. IOW:
+	 * (size of currently enqueued TRBs + remainder) % wMaxPacketSize == 0.
+	 */
+	new_buff_len = max_pkt - (enqd_len % max_pkt);
+
+	if (new_buff_len > (req_priv->request.length - enqd_len))
+		new_buff_len = (req_priv->request.length - enqd_len);
+
+	/* create a max max_pkt sized bounce buffer pointed to by last trb */
+	if (req_priv->direction) {
+		sg_pcopy_to_buffer(req_priv->request.sg,
+				req_priv->request.num_mapped_sgs,
+				seg->bounce_buf, new_buff_len, enqd_len);
+		seg->bounce_dma = dma_map_single(dev, seg->bounce_buf,
+						max_pkt, DMA_TO_DEVICE);
+	} else {
+		seg->bounce_dma = dma_map_single(dev, seg->bounce_buf,
+						max_pkt, DMA_FROM_DEVICE);
+	}
+
+	if (dma_mapping_error(dev, seg->bounce_dma)) {
+		/* try without aligning.*/
+		usbssp_warn(usbssp_data,
+			"Failed mapping bounce buffer, not aligning\n");
+		return 0;
+	}
+	*trb_buff_len = new_buff_len;
+	seg->bounce_len = new_buff_len;
+	seg->bounce_offs = enqd_len;
+
+	usbssp_dbg(usbssp_data, "Bounce align, new buff len %d\n",
+			*trb_buff_len);
+
+	return 1;
+}
+
+int usbssp_queue_bulk_tx(struct usbssp_udc *usbssp_data,
+			 gfp_t mem_flags,
+			 struct usbssp_request *req_priv,
+			 unsigned int ep_index)
+{
+	struct usbssp_ring *ring;
+	struct usbssp_td *td;
+	struct usbssp_generic_trb *start_trb;
+	struct scatterlist *sg = NULL;
+	bool more_trbs_coming = true;
+	bool need_zero_pkt = false;
+	bool first_trb = true;
+	unsigned int num_trbs;
+	unsigned int start_cycle, num_sgs = 0;
+	unsigned int enqd_len, block_len, trb_buff_len, full_len;
+	int sent_len, ret;
+	u32 field, length_field, remainder;
+	u64 addr, send_addr;
+
+	ring = usbssp_request_to_transfer_ring(usbssp_data, req_priv);
+	if (!ring)
+		return -EINVAL;
+
+	full_len = req_priv->request.length;
+	/* If we have scatter/gather list, we use it. */
+	if (req_priv->request.num_sgs) {
+		num_sgs = req_priv->num_pending_sgs;
+		sg = req_priv->sg;
+		addr = (u64) sg_dma_address(sg);
+		block_len = sg_dma_len(sg);
+		num_trbs = count_sg_trbs_needed(req_priv);
+	} else {
+		num_trbs = count_trbs_needed(req_priv);
+		addr = (u64) req_priv->request.dma;
+		block_len = full_len;
+	}
+
+	ret = prepare_transfer(usbssp_data, &usbssp_data->devs,
+			ep_index, req_priv->request.stream_id,
+			num_trbs, req_priv, 0, mem_flags);
+	if (unlikely(ret < 0))
+		return ret;
+
+	/* Deal with request.zero - need one more td/trb */
+	if (req_priv->request.zero && req_priv->num_tds_done > 1)
+		need_zero_pkt = true;
+
+	td = &req_priv->td[0];
+
+	usbssp_dbg(usbssp_data, "Queue Bulk transfer to %s - ep_index: %d,"
+				" num trb: %d, block len %d, nzp: %d\n",
+				req_priv->dep->name, ep_index,
+				num_trbs, block_len, need_zero_pkt);
+
+	/*
+	 * Don't give the first TRB to the hardware (by toggling the cycle bit)
+	 * until we've finished creating all the other TRBs.  The ring's cycle
+	 * state may change as we enqueue the other TRBs, so save it too.
+	 */
+	start_trb = &ring->enqueue->generic;
+	start_cycle = ring->cycle_state;
+	send_addr = addr;
+
+	/* Queue the TRBs, even if they are zero-length */
+	for (enqd_len = 0; first_trb || enqd_len < full_len;
+			enqd_len += trb_buff_len) {
+		field = TRB_TYPE(TRB_NORMAL);
+
+		/* TRB buffer should not cross 64KB boundaries */
+		trb_buff_len = TRB_BUFF_LEN_UP_TO_BOUNDARY(addr);
+		trb_buff_len = min_t(unsigned int, trb_buff_len, block_len);
+
+		if (enqd_len + trb_buff_len > full_len)
+			trb_buff_len = full_len - enqd_len;
+
+		/* Don't change the cycle bit of the first TRB until later */
+		if (first_trb) {
+			first_trb = false;
+			if (start_cycle == 0)
+				field |= TRB_CYCLE;
+		} else
+			field |= ring->cycle_state;
+
+		/* Chain all the TRBs together; clear the chain bit in the last
+		 * TRB to indicate it's the last TRB in the chain.
+		 */
+		if (enqd_len + trb_buff_len < full_len) {
+			field |= TRB_CHAIN;
+			if (trb_is_link(ring->enqueue + 1)) {
+				if (usbssp_align_td(usbssp_data, req_priv,
+					enqd_len, &trb_buff_len,
+					ring->enq_seg)) {
+					send_addr = ring->enq_seg->bounce_dma;
+					/* assuming TD won't span 2 segs */
+					td->bounce_seg = ring->enq_seg;
+				}
+			}
+		}
+		if (enqd_len + trb_buff_len >= full_len) {
+			field &= ~TRB_CHAIN;
+			field |= TRB_IOC;
+			more_trbs_coming = false;
+			td->last_trb = ring->enqueue;
+		}
+
+		/* Only set interrupt on short packet for OUT endpoints */
+		if (!req_priv->direction)
+			field |= TRB_ISP;
+
+		/* Set the TRB length, TD size, and interrupter fields. */
+		remainder = usbssp_td_remainder(usbssp_data, enqd_len,
+				trb_buff_len, full_len, req_priv,
+				more_trbs_coming);
+
+		length_field = TRB_LEN(trb_buff_len) |
+			TRB_TD_SIZE(remainder) |
+			TRB_INTR_TARGET(0);
+
+		queue_trb(usbssp_data, ring, more_trbs_coming | need_zero_pkt,
+				lower_32_bits(send_addr),
+				upper_32_bits(send_addr),
+				length_field,
+				field);
+
+		addr += trb_buff_len;
+		sent_len = trb_buff_len;
+
+		while (sg && sent_len >= block_len) {
+			/* New sg entry */
+			--num_sgs;
+			sent_len -= block_len;
+			if (num_sgs != 0) {
+				sg = sg_next(sg);
+				block_len = sg_dma_len(sg);
+				addr = (u64) sg_dma_address(sg);
+				addr += sent_len;
+			}
+		}
+		block_len -= sent_len;
+		send_addr = addr;
+	}
+
+	if (need_zero_pkt) {
+		ret = prepare_transfer(usbssp_data, &usbssp_data->devs,
+				ep_index, req_priv->request.stream_id,
+				1, req_priv, 1, mem_flags);
+		req_priv->td[1].last_trb = ring->enqueue;
+		field = TRB_TYPE(TRB_NORMAL) | ring->cycle_state | TRB_IOC;
+		queue_trb(usbssp_data, ring, 0, 0, 0,
+				TRB_INTR_TARGET(0), field);
+	}
+
+	check_trb_math(req_priv, enqd_len);
+	giveback_first_trb(usbssp_data,  ep_index, req_priv->request.stream_id,
+			start_cycle, start_trb);
+	return 0;
+}
+
+int usbssp_queue_ctrl_tx(struct usbssp_udc *usbssp_data,
+			 gfp_t mem_flags,
+			 struct usbssp_request *req_priv,
+			 unsigned int ep_index)
+{
+	struct usbssp_ring *ep_ring;
+	int num_trbs;
+	int ret;
+	struct usbssp_generic_trb *start_trb;
+	int start_cycle;
+	u32 field, length_field, remainder;
+	struct usbssp_td *td;
+	struct usbssp_ep *dep = req_priv->dep;
+
+	ep_ring = usbssp_request_to_transfer_ring(usbssp_data, req_priv);
+	if (!ep_ring)
+		return -EINVAL;
+
+	if (usbssp_data->delayed_status) {
+		usbssp_dbg(usbssp_data, "Queue CTRL: delayed finished\n");
+		usbssp_data->delayed_status = false;
+		usb_gadget_set_state(&usbssp_data->gadget,
+				USB_STATE_CONFIGURED);
+	}
+
+	if (usbssp_data->bos_event_detected) {
+		usbssp_data->bos_event_detected = 0;
+		usb_gadget_unmap_request_by_dev(usbssp_data->dev,
+				&req_priv->request,
+			dep->direction);
+		usbssp_set_usb2_hardware_lpm(usbssp_data,
+				&req_priv->request, 1);
+		ret = usb_gadget_map_request_by_dev(usbssp_data->dev,
+				&req_priv->request, dep->direction);
+	}
+
+	/* 1 TRB for data, 1 for status */
+	if (usbssp_data->three_stage_setup)
+		num_trbs = 2;
+	else
+		num_trbs = 1;
+
+	ret = prepare_transfer(usbssp_data, &usbssp_data->devs,
+			req_priv->epnum, req_priv->request.stream_id,
+			num_trbs, req_priv, 0, mem_flags);
+
+	if (ret < 0)
+		return ret;
+
+	td = &req_priv->td[0];
+	/*
+	 * Don't give the first TRB to the hardware (by toggling the cycle bit)
+	 * until we've finished creating all the other TRBs.  The ring's cycle
+	 * state may change as we enqueue the other TRBs, so save it too.
+	 */
+	start_trb = &ep_ring->enqueue->generic;
+	start_cycle = ep_ring->cycle_state;
+
+	/* If there's data, queue data TRBs */
+	/* Only set interrupt on short packet for OUT endpoints */
+
+	if (usbssp_data->ep0_expect_in)
+		field = TRB_TYPE(TRB_DATA) | TRB_IOC;
+	else
+		field = TRB_ISP | TRB_TYPE(TRB_DATA) | TRB_IOC;
+
+	if (req_priv->request.length > 0) {
+		remainder = usbssp_td_remainder(usbssp_data, 0,
+				req_priv->request.length,
+				req_priv->request.length, req_priv, 1);
+
+		length_field = TRB_LEN(req_priv->request.length) |
+			TRB_TD_SIZE(remainder) |
+			TRB_INTR_TARGET(0);
+
+		if (usbssp_data->ep0_expect_in)
+			field |= TRB_DIR_IN;
+
+		queue_trb(usbssp_data, ep_ring, true,
+				lower_32_bits(req_priv->request.dma),
+				upper_32_bits(req_priv->request.dma),
+				length_field,
+				field | ep_ring->cycle_state |
+				TRB_SETUPID(usbssp_data->setupId) |
+				usbssp_data->setup_speed);
+		usbssp_data->ep0state = USBSSP_EP0_DATA_PHASE;
+	}
+
+	/* Save the DMA address of the last TRB in the TD */
+	td->last_trb = ep_ring->enqueue;
+
+	/* Queue status TRB*/
+	/* If the device sent data, the status stage is an OUT transfer */
+
+	if (req_priv->request.length > 0 && usbssp_data->ep0_expect_in)
+		field = TRB_DIR_IN;
+	else
+		field = 0;
+
+	if (req_priv->request.length == 0)
+		field  |= ep_ring->cycle_state;
+	else
+		field |= (ep_ring->cycle_state ^ 1);
+
+	if (dep->ep_state & EP0_HALTED_STATUS) {
+		/* If endpoint should be halted in Status Stage then
+		 * driver shall set TRB_SETUPSTAT_STALL bit
+		 */
+		usbssp_dbg(usbssp_data,
+				"Status Stage phase prepared with STALL bit\n");
+		dep->ep_state &= ~EP0_HALTED_STATUS;
+		field |= TRB_SETUPSTAT(TRB_SETUPSTAT_STALL);
+	} else {
+		field |= TRB_SETUPSTAT(TRB_SETUPSTAT_ACK);
+	}
+
+	queue_trb(usbssp_data, ep_ring, false,
+			0,
+			0,
+			TRB_INTR_TARGET(0),
+			/* Event on completion */
+			field | TRB_IOC |  TRB_SETUPID(usbssp_data->setupId) |
+			TRB_TYPE(TRB_STATUS) | usbssp_data->setup_speed);
+
+	usbssp_dbg_ep_rings(usbssp_data, 0, dep);
+	usbssp_ring_ep_doorbell(usbssp_data,  ep_index,
+			req_priv->request.stream_id);
+	return 0;
+}
+
+/* Stop endpoint after disconnecting device.*/
+int usbssp_cmd_stop_ep(struct usbssp_udc *usbssp_data, struct usb_gadget *g,
+		       struct usbssp_ep *ep_priv)
+{
+	int ret = 0;
+	struct usbssp_command *command;
+	unsigned int ep_index;
+	struct usbssp_container_ctx *out_ctx;
+	struct usbssp_ep_ctx *ep_ctx;
+	int interrupt_disabled_locally = 0;
+
+	ep_index = usbssp_get_endpoint_index(ep_priv->endpoint.desc);
+
+	if ((ep_priv->ep_state & EP_STOP_CMD_PENDING)) {
+		usbssp_dbg(usbssp_data,
+			"Stop endpoint command on %s (index: %d) is pending\n",
+			ep_priv->name, ep_index);
+		return 0;
+	}
+
+	command = usbssp_alloc_command(usbssp_data, true, GFP_ATOMIC);
+	if (!command)
+		return -ENOMEM;
+
+	ep_priv->ep_state |= EP_STOP_CMD_PENDING;
+
+	usbssp_queue_stop_endpoint(usbssp_data, command,
+			ep_index, 0);
+	usbssp_ring_cmd_db(usbssp_data);
+
+	out_ctx = usbssp_data->devs.out_ctx;
+	ep_ctx = usbssp_get_ep_ctx(usbssp_data, out_ctx, ep_index);
+
+	if (irqs_disabled()) {
+		spin_unlock_irqrestore(&usbssp_data->irq_thread_lock,
+				usbssp_data->irq_thread_flag);
+		interrupt_disabled_locally = 1;
+	} else {
+		spin_unlock(&usbssp_data->irq_thread_lock);
+	}
+
+	/* Wait for last stop endpoint command to finish */
+	wait_for_completion(command->completion);
+
+	if (interrupt_disabled_locally)
+		spin_lock_irqsave(&usbssp_data->irq_thread_lock,
+				usbssp_data->irq_thread_flag);
+	else
+		spin_lock(&usbssp_data->irq_thread_lock);
+
+	if (command->status == COMP_COMMAND_ABORTED ||
+			command->status == COMP_COMMAND_RING_STOPPED) {
+		usbssp_warn(usbssp_data,
+			"Timeout while waiting for stop endpoint command\n");
+		ret = -ETIME;
+	}
+
+	usbssp_free_command(usbssp_data, command);
+	return ret;
+}
+
+/*
+ * The transfer burst count field of the isochronous TRB defines the number of
+ * bursts that are required to move all packets in this TD.  Only SuperSpeed
+ * devices can burst up to bMaxBurst number of packets per service interval.
+ * This field is zero based, meaning a value of zero in the field means one
+ * burst.  Basically, for everything but SuperSpeed devices, this field will be
+ * zero.
+ */
+static unsigned int usbssp_get_burst_count(struct usbssp_udc *usbssp_data,
+					   struct usbssp_request *req_priv,
+					   unsigned int total_packet_count)
+{
+	unsigned int max_burst;
+
+	if (usbssp_data->gadget.speed < USB_SPEED_SUPER)
+		return 0;
+
+	max_burst = req_priv->dep->endpoint.comp_desc->bMaxBurst;
+	return DIV_ROUND_UP(total_packet_count, max_burst + 1) - 1;
+}
+
+/*
+ * Returns the number of packets in the last "burst" of packets.  This field is
+ * valid for all speeds of devices.  USB 2.0 devices can only do one "burst", so
+ * the last burst packet count is equal to the total number of packets in the
+ * TD.  SuperSpeed endpoints can have up to 3 bursts.  All but the last burst
+ * must contain (bMaxBurst + 1) number of packets, but the last burst can
+ * contain 1 to (bMaxBurst + 1) packets.
+ */
+static unsigned int usbssp_get_last_burst_packet_count(
+					struct usbssp_udc *usbssp_data,
+					struct usbssp_request *req_priv,
+					unsigned int total_packet_count)
+{
+	unsigned int max_burst;
+	unsigned int residue;
+
+	if (usbssp_data->gadget.speed >= USB_SPEED_SUPER) {
+		/* bMaxBurst is zero based: 0 means 1 packet per burst */
+		max_burst = req_priv->dep->endpoint.comp_desc->bMaxBurst;
+		residue = total_packet_count % (max_burst + 1);
+		/* If residue is zero, the last burst contains (max_burst + 1)
+		 * number of packets, but the TLBPC field is zero-based.
+		 */
+		if (residue == 0)
+			return max_burst;
+		return residue - 1;
+	}
+	if (total_packet_count == 0)
+		return 0;
+	return total_packet_count - 1;
+}
+
+/*
+ * Calculates Frame ID field of the isochronous TRB identifies the
+ * target frame that the Interval associated with this Isochronous
+ * Transfer Descriptor will start on.
+ *
+ * Returns actual frame id on success, negative value on error.
+ */
+static int usbssp_get_isoc_frame_id(struct usbssp_udc *usbssp_data,
+		struct usbssp_request *req_priv, int index)
+{
+	int start_frame = 0, ist, ret = 0;
+	int start_frame_id, end_frame_id, current_frame_id;
+
+	/* Isochronous Scheduling Threshold (IST, bits 0~3 in HCSPARAMS2):
+	 *
+	 * If bit [3] of IST is cleared to '0', software can add a TRB no
+	 * later than IST[2:0] Microframes before that TRB is scheduled to
+	 * be executed.
+	 * If bit [3] of IST is set to '1', software can add a TRB no later
+	 * than IST[2:0] Frames before that TRB is scheduled to be executed.
+	 */
+	ist = HCS_IST(usbssp_data->hcs_params2) & 0x7;
+	if (HCS_IST(usbssp_data->hcs_params2) & (1 << 3))
+		ist <<= 3;
+
+	/* Software shall not schedule an Isoch TD with a Frame ID value that
+	 * is less than the Start Frame ID or greater than the End Frame ID,
+	 * where:
+	 *
+	 * End Frame ID = (Current MFINDEX register value + 895 ms.) MOD 2048
+	 * Start Frame ID = (Current MFINDEX register value + IST + 1) MOD 2048
+	 *
+	 * Both the End Frame ID and Start Frame ID values are calculated
+	 * in microframes. When software determines the valid Frame ID value;
+	 * The End Frame ID value should be rounded down to the nearest Frame
+	 * boundary, and the Start Frame ID value should be rounded up to the
+	 * nearest Frame boundary.
+	 */
+	current_frame_id = readl(&usbssp_data->run_regs->microframe_index);
+	start_frame_id = roundup(current_frame_id + ist + 1, 8);
+	end_frame_id = rounddown(current_frame_id + 895 * 8, 8);
+
+	start_frame &= 0x7ff;
+	start_frame_id = (start_frame_id >> 3) & 0x7ff;
+	end_frame_id = (end_frame_id >> 3) & 0x7ff;
+
+	usbssp_dbg(usbssp_data, "%s: index %d, reg 0x%x start_frame_id 0x%x,"
+		"end_frame_id 0x%x, start_frame 0x%x\n",
+		 __func__, index,
+		 readl(&usbssp_data->run_regs->microframe_index),
+		 start_frame_id, end_frame_id, start_frame);
+
+	if (start_frame_id < end_frame_id) {
+		if (start_frame > end_frame_id || start_frame < start_frame_id)
+			ret = -EINVAL;
+	} else if (start_frame_id > end_frame_id) {
+		if (start_frame > end_frame_id && start_frame < start_frame_id)
+			ret = -EINVAL;
+	} else {
+		ret = -EINVAL;
+	}
+
+	if (index == 0) {
+		if (ret == -EINVAL || start_frame == start_frame_id) {
+			start_frame = start_frame_id + 1;
+			if (usbssp_data->gadget.speed == USB_SPEED_LOW ||
+			    usbssp_data->gadget.speed == USB_SPEED_FULL)
+				req_priv->start_frame = start_frame;
+			else
+				req_priv->start_frame = start_frame << 3;
+			ret = 0;
+		}
+	}
+
+	if (ret) {
+		usbssp_warn(usbssp_data,
+			"Frame ID %d (reg %d, index %d) beyond range (%d, %d)\n",
+			start_frame, current_frame_id, index,
+			start_frame_id, end_frame_id);
+		usbssp_warn(usbssp_data,
+			"Ignore frame ID field, use SIA bit instead\n");
+		return ret;
+	}
+
+	return start_frame;
+}
+
+/* This is for isoc transfer */
+static int usbssp_queue_isoc_tx(struct usbssp_udc *usbssp_data,
+				gfp_t mem_flags,
+				struct usbssp_request *req_priv,
+				unsigned int ep_index)
+{
+	struct usbssp_ring *ep_ring;
+	struct usbssp_td *td;
+	int num_tds, trbs_per_td;
+	struct usbssp_generic_trb *start_trb;
+	bool first_trb;
+	int start_cycle;
+	u32 field, length_field;
+	int running_total, trb_buff_len, td_len, td_remain_len, ret;
+	u64 start_addr, addr;
+	int i, j;
+	bool more_trbs_coming;
+	struct usbssp_ep *ep_priv;
+	int frame_id;
+
+	ep_priv = &usbssp_data->devs.eps[ep_index];
+	ep_ring = usbssp_data->devs.eps[ep_index].ring;
+
+	num_tds = 1;
+
+	if (num_tds < 1) {
+		usbssp_dbg(usbssp_data, "Isoc request with zero packets?\n");
+		return -EINVAL;
+	}
+	start_addr = (u64) req_priv->request.dma;
+	start_trb = &ep_ring->enqueue->generic;
+	start_cycle = ep_ring->cycle_state;
+
+
+	/* Queue the TRBs for each TD, even if they are zero-length */
+	for (i = 0; i < num_tds; i++) {
+		unsigned int total_pkt_count, max_pkt;
+		unsigned int burst_count, last_burst_pkt_count;
+		u32 sia_frame_id;
+
+		first_trb = true;
+		running_total = 0;
+		addr = start_addr;
+		td_len = req_priv->request.length;
+		td_remain_len = td_len;
+		max_pkt = GET_MAX_PACKET(usb_endpoint_maxp(req_priv->dep->endpoint.desc));
+		total_pkt_count = DIV_ROUND_UP(td_len, max_pkt);
+
+		/* A zero-length transfer still involves at least one packet. */
+		if (total_pkt_count == 0)
+			total_pkt_count++;
+		burst_count = usbssp_get_burst_count(usbssp_data, req_priv,
+				total_pkt_count);
+		last_burst_pkt_count = usbssp_get_last_burst_packet_count(
+				usbssp_data, req_priv, total_pkt_count);
+
+		trbs_per_td = count_isoc_trbs_needed(req_priv);
+
+		ret = prepare_transfer(usbssp_data, &usbssp_data->devs,
+				ep_index, req_priv->request.stream_id,
+				trbs_per_td, req_priv, i, mem_flags);
+		if (ret < 0) {
+			if (i == 0)
+				return ret;
+			goto cleanup;
+		}
+		td = &req_priv->td[i];
+
+		/* use SIA as default, if frame id is used overwrite it */
+		sia_frame_id = TRB_SIA;
+		if (HCC_CFC(usbssp_data->hcc_params)) {
+			frame_id = usbssp_get_isoc_frame_id(usbssp_data,
+					req_priv, i);
+			if (frame_id >= 0)
+				sia_frame_id = TRB_FRAME_ID(frame_id);
+		}
+		/*
+		 * Set isoc specific data for the first TRB in a TD.
+		 * Prevent HW from getting the TRBs by keeping the cycle state
+		 * inverted in the first TDs isoc TRB.
+		 */
+		field = TRB_TYPE(TRB_ISOC) |
+			TRB_TLBPC(last_burst_pkt_count) |
+			sia_frame_id |
+			(i ? ep_ring->cycle_state : !start_cycle);
+
+		if (!ep_priv->use_extended_tbc)
+			field |= TRB_TBC(burst_count);
+
+		/* fill the rest of the TRB fields, and remaining normal TRBs */
+		for (j = 0; j < trbs_per_td; j++) {
+			u32 remainder = 0;
+
+			/* only first TRB is isoc, overwrite otherwise */
+			if (!first_trb)
+				field = TRB_TYPE(TRB_NORMAL) |
+					ep_ring->cycle_state;
+
+			/* Only set interrupt on short packet for IN EPs */
+			if (usb_endpoint_dir_out(req_priv->dep->endpoint.desc))
+				field |= TRB_ISP;
+
+			/* Set the chain bit for all except the last TRB  */
+			if (j < trbs_per_td - 1) {
+				more_trbs_coming = true;
+				field |= TRB_CHAIN;
+			} else {
+				more_trbs_coming = false;
+				td->last_trb = ep_ring->enqueue;
+				field |= TRB_IOC;
+				/* set BEI, except for the last TD */
+				if (i < num_tds - 1)
+					field |= TRB_BEI;
+			}
+			/* Calculate TRB length */
+			trb_buff_len = TRB_BUFF_LEN_UP_TO_BOUNDARY(addr);
+			if (trb_buff_len > td_remain_len)
+				trb_buff_len = td_remain_len;
+
+			/* Set the TRB length, TD size, & interrupter fields. */
+			remainder = usbssp_td_remainder(usbssp_data,
+					running_total, trb_buff_len, td_len,
+					req_priv, more_trbs_coming);
+
+			length_field = TRB_LEN(trb_buff_len) |
+				TRB_INTR_TARGET(0);
+
+			if (first_trb && ep_priv->use_extended_tbc)
+				length_field |= TRB_TD_SIZE_TBC(burst_count);
+			else
+				length_field |= TRB_TD_SIZE(remainder);
+			first_trb = false;
+
+			queue_trb(usbssp_data, ep_ring, more_trbs_coming,
+				lower_32_bits(addr),
+				upper_32_bits(addr),
+				length_field,
+				field);
+			running_total += trb_buff_len;
+
+			addr += trb_buff_len;
+			td_remain_len -= trb_buff_len;
+		}
+
+		/* Check TD length */
+		if (running_total != td_len) {
+			usbssp_err(usbssp_data, "ISOC TD length unmatch\n");
+			ret = -EINVAL;
+			goto cleanup;
+		}
+	}
+
+	/* store the next frame id */
+//	if (HCC_CFC(usbssp_data->hcc_params))
+//		ep_priv->next_frame_id = req_priv->start_frame + num_tds *
+//			req_priv->request.interval;
+
+	giveback_first_trb(usbssp_data,  ep_index, req_priv->request.stream_id,
+			start_cycle, start_trb);
+	return 0;
+cleanup:
+	/* Clean up a partially enqueued isoc transfer. */
+
+	for (i--; i >= 0; i--)
+		list_del_init(&req_priv->td[i].td_list);
+
+	/* Use the first TD as a temporary variable to turn the TDs we've queued
+	 * into No-ops with a software-owned cycle bit. That way the hardware
+	 * won't accidentally start executing bogus TDs when we partially
+	 * overwrite them.  td->first_trb and td->start_seg are already set.
+	 */
+	req_priv->td[0].last_trb = ep_ring->enqueue;
+	/* Every TRB except the first & last will have its cycle bit flipped. */
+	td_to_noop(usbssp_data, ep_ring, &req_priv->td[0], true);
+
+	/* Reset the ring enqueue back to the first TRB and its cycle bit. */
+	ep_ring->enqueue = req_priv->td[0].first_trb;
+	ep_ring->enq_seg = req_priv->td[0].start_seg;
+	ep_ring->cycle_state = start_cycle;
+	ep_ring->num_trbs_free = ep_ring->num_trbs_free_temp;
+	return ret;
+}
+
+int usbssp_queue_isoc_tx_prepare(struct usbssp_udc *usbssp_data,
+				 gfp_t mem_flags,
+				 struct usbssp_request *req_priv,
+				 unsigned int ep_index)
+{
+	struct usbssp_device *dev_priv;
+	struct usbssp_ring *ep_ring;
+	struct usbssp_ep_ctx *ep_ctx;
+	int start_frame;
+	int num_trbs;
+	int ret;
+	struct usbssp_ep *ep_priv;
+	int ist;
+
+	dev_priv = &usbssp_data->devs;
+	ep_priv = &usbssp_data->devs.eps[ep_index];
+	ep_ring = usbssp_data->devs.eps[ep_index].ring;
+	ep_ctx = usbssp_get_ep_ctx(usbssp_data, dev_priv->out_ctx, ep_index);
+
+	/*Single usb_request can use only one TD, Linux gadget drivers doesn't
+	 * use sg for isoc so sg will be omitted
+	 */
+	num_trbs = count_isoc_trbs_needed(req_priv);
+
+
+	/* Check the ring to guarantee there is enough room for the whole
+	 * request. Do not insert any td of the USB Request to the ring if the
+	 * check failed.
+	 */
+	ret = prepare_ring(usbssp_data, ep_ring, GET_EP_CTX_STATE(ep_ctx),
+			   num_trbs, mem_flags);
+	if (ret)
+		return ret;
+
+	if (HCC_CFC(usbssp_data->hcc_params) && !list_empty(&ep_ring->td_list)) {
+		if ((le32_to_cpu(ep_ctx->ep_info) & EP_STATE_MASK) ==
+		     EP_STATE_RUNNING) {
+			req_priv->start_frame = ep_priv->next_frame_id;
+			goto skip_start_over;
+		}
+	}
+
+	start_frame = readl(&usbssp_data->run_regs->microframe_index);
+	start_frame &= 0x3fff;
+	/*
+	 * Round up to the next frame and consider the time before trb really
+	 * gets scheduled by hardare.
+	 */
+	ist = HCS_IST(usbssp_data->hcs_params2) & 0x7;
+	if (HCS_IST(usbssp_data->hcs_params2) & (1 << 3))
+		ist <<= 3;
+	start_frame += ist + USBSSP_CFC_DELAY;
+	start_frame = roundup(start_frame, 8);
+skip_start_over:
+	ep_ring->num_trbs_free_temp = ep_ring->num_trbs_free;
+
+	return usbssp_queue_isoc_tx(usbssp_data, mem_flags, req_priv, ep_index);
+}
+
+/****		Command Ring Operations		****/
+/* Generic function for queueing a command TRB on the command ring.
+ * Check to make sure there's room on the command ring for one command TRB.
+ * Also check that there's room reserved for commands that must not fail.
+ * If this is a command that must not fail, meaning command_must_succeed = TRUE,
+ * then only check for the number of reserved spots.
+ * Don't decrement usbssp_data->cmd_ring_reserved_trbs after we've queued the
+ * TRB because the command event handler may want to resubmit a failed command.
+ */
+static int queue_command(struct usbssp_udc *usbssp_data,
+			 struct usbssp_command *cmd,
+			 u32 field1, u32 field2,
+			 u32 field3, u32 field4,
+			 bool command_must_succeed)
+{
+	int reserved_trbs = usbssp_data->cmd_ring_reserved_trbs;
+	int ret;
+
+	if ((usbssp_data->usbssp_state & USBSSP_STATE_DYING) ||
+		(usbssp_data->usbssp_state & USBSSP_STATE_HALTED)) {
+		usbssp_dbg(usbssp_data,
+			"USBSSP dying or halted, can't queue command\n");
+		return -ESHUTDOWN;
+	}
+
+	if (!command_must_succeed)
+		reserved_trbs++;
+
+	ret = prepare_ring(usbssp_data, usbssp_data->cmd_ring, EP_STATE_RUNNING,
+			reserved_trbs, GFP_ATOMIC);
+	if (ret < 0) {
+		usbssp_err(usbssp_data,
+			"ERR: No room for command on command ring\n");
+		if (command_must_succeed)
+			usbssp_err(usbssp_data,
+				"ERR: Reserved TRB counting for "
+				"unfailable commands failed.\n");
+		return ret;
+	}
+
+	cmd->command_trb = usbssp_data->cmd_ring->enqueue;
+
+	/* if there are no other commands queued we start the timeout timer */
+	if (list_empty(&usbssp_data->cmd_list)) {
+		usbssp_data->current_cmd = cmd;
+		usbssp_mod_cmd_timer(usbssp_data, USBSSP_CMD_DEFAULT_TIMEOUT);
+	}
+
+	list_add_tail(&cmd->cmd_list, &usbssp_data->cmd_list);
+
+	queue_trb(usbssp_data, usbssp_data->cmd_ring, false, field1, field2,
+		field3, field4 | usbssp_data->cmd_ring->cycle_state);
+	return 0;
+}
+
+/* Queue a slot enable or disable request on the command ring */
+int usbssp_queue_slot_control(struct usbssp_udc *usbssp_data,
+			      struct usbssp_command *cmd,
+			      u32 trb_type)
+{
+	return queue_command(usbssp_data, cmd, 0, 0, 0,
+			TRB_TYPE(trb_type) |
+			SLOT_ID_FOR_TRB(usbssp_data->slot_id), false);
+}
+
+/* Queue an address device command TRB */
+int usbssp_queue_address_device(struct usbssp_udc *usbssp_data,
+				struct usbssp_command *cmd,
+				dma_addr_t in_ctx_ptr,
+				enum usbssp_setup_dev setup)
+{
+	return queue_command(usbssp_data, cmd, lower_32_bits(in_ctx_ptr),
+			upper_32_bits(in_ctx_ptr), 0,
+			TRB_TYPE(TRB_ADDR_DEV) |
+			SLOT_ID_FOR_TRB(usbssp_data->slot_id)
+			| (setup == SETUP_CONTEXT_ONLY ? TRB_BSR : 0), false);
+}
+
+int usbssp_queue_vendor_command(struct usbssp_udc *usbssp_data,
+				struct usbssp_command *cmd,
+				u32 field1, u32 field2, u32 field3, u32 field4)
+{
+	return queue_command(usbssp_data, cmd, field1, field2, field3,
+			field4, false);
+}
+
+/* Queue a reset device command TRB */
+int usbssp_queue_reset_device(struct usbssp_udc *usbssp_data,
+			      struct usbssp_command *cmd)
+{
+	return queue_command(usbssp_data, cmd, 0, 0, 0,
+			TRB_TYPE(TRB_RESET_DEV) |
+			SLOT_ID_FOR_TRB(usbssp_data->slot_id),
+			false);
+}
+
+/* Queue a configure endpoint command TRB */
+int usbssp_queue_configure_endpoint(struct usbssp_udc *usbssp_data,
+				    struct usbssp_command *cmd,
+				    dma_addr_t in_ctx_ptr,
+				    bool command_must_succeed)
+{
+	return queue_command(usbssp_data, cmd, lower_32_bits(in_ctx_ptr),
+			upper_32_bits(in_ctx_ptr), 0,
+			TRB_TYPE(TRB_CONFIG_EP) |
+			SLOT_ID_FOR_TRB(usbssp_data->slot_id),
+			command_must_succeed);
+}
+
+/* Queue an evaluate context command TRB */
+int usbssp_queue_evaluate_context(struct usbssp_udc *usbssp_data,
+				  struct usbssp_command *cmd,
+				  dma_addr_t in_ctx_ptr,
+				  bool command_must_succeed)
+{
+	return queue_command(usbssp_data, cmd, lower_32_bits(in_ctx_ptr),
+			upper_32_bits(in_ctx_ptr), 0,
+			TRB_TYPE(TRB_EVAL_CONTEXT) |
+			SLOT_ID_FOR_TRB(usbssp_data->slot_id),
+			command_must_succeed);
+}
+
+/*
+ * Suspend is set to indicate "Stop Endpoint Command" is being issued to stop
+ * activity on an endpoint that is about to be suspended.
+ */
+int usbssp_queue_stop_endpoint(struct usbssp_udc *usbssp_data,
+			       struct usbssp_command *cmd,
+			       unsigned int ep_index, int suspend)
+{
+	u32 trb_slot_id = SLOT_ID_FOR_TRB(usbssp_data->slot_id);
+	u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
+	u32 type = TRB_TYPE(TRB_STOP_RING);
+	u32 trb_suspend = SUSPEND_PORT_FOR_TRB(suspend);
+
+	return queue_command(usbssp_data, cmd, 0, 0, 0,
+			trb_slot_id | trb_ep_index | type | trb_suspend, false);
+}
+
+/* Set Transfer Ring Dequeue Pointer command */
+void usbssp_queue_new_dequeue_state(struct  usbssp_udc *usbssp_data,
+				    unsigned int ep_index,
+				    struct usbssp_dequeue_state *deq_state)
+{
+	dma_addr_t addr;
+	u32 trb_slot_id = SLOT_ID_FOR_TRB(usbssp_data->slot_id);
+	u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
+	u32 trb_stream_id = STREAM_ID_FOR_TRB(deq_state->stream_id);
+	u32 trb_sct = 0;
+	u32 type = TRB_TYPE(TRB_SET_DEQ);
+	struct usbssp_ep *ep_priv;
+	struct usbssp_command *cmd;
+	int ret;
+
+	usbssp_dbg_trace(usbssp_data, trace_usbssp_dbg_cancel_request,
+		"Set TR Deq Ptr cmd, new deq seg = %p (0x%llx dma), "
+		"new deq ptr = %p (0x%llx dma), new cycle = %u",
+		deq_state->new_deq_seg,
+		(unsigned long long)deq_state->new_deq_seg->dma,
+		deq_state->new_deq_ptr,
+		(unsigned long long)usbssp_trb_virt_to_dma(
+			deq_state->new_deq_seg, deq_state->new_deq_ptr),
+		deq_state->new_cycle_state);
+
+	addr = usbssp_trb_virt_to_dma(deq_state->new_deq_seg,
+				    deq_state->new_deq_ptr);
+	if (addr == 0) {
+		usbssp_warn(usbssp_data, "WARN Cannot submit Set TR Deq Ptr\n");
+		usbssp_warn(usbssp_data, "WARN deq seg = %p, deq pt = %p\n",
+			  deq_state->new_deq_seg, deq_state->new_deq_ptr);
+		return;
+	}
+	ep_priv = &usbssp_data->devs.eps[ep_index];
+	if ((ep_priv->ep_state & SET_DEQ_PENDING)) {
+		usbssp_warn(usbssp_data, "WARN Cannot submit Set TR Deq Ptr\n");
+		usbssp_warn(usbssp_data,
+			"A Set TR Deq Ptr command is pending.\n");
+		return;
+	}
+
+	/* This function gets called from contexts where it cannot sleep */
+	cmd = usbssp_alloc_command(usbssp_data, false, GFP_ATOMIC);
+	if (!cmd) {
+		usbssp_warn(usbssp_data,
+			"WARN Cannot submit Set TR Deq Ptr: ENOMEM\n");
+		return;
+	}
+
+	ep_priv->queued_deq_seg = deq_state->new_deq_seg;
+	ep_priv->queued_deq_ptr = deq_state->new_deq_ptr;
+	if (deq_state->stream_id)
+		trb_sct = SCT_FOR_TRB(SCT_PRI_TR);
+	ret = queue_command(usbssp_data, cmd,
+		lower_32_bits(addr) | trb_sct | deq_state->new_cycle_state,
+		upper_32_bits(addr), trb_stream_id,
+		trb_slot_id | trb_ep_index | type, false);
+	if (ret < 0) {
+		usbssp_free_command(usbssp_data, cmd);
+		return;
+	}
+
+	/* Stop the TD queueing code from ringing the doorbell until
+	 * this command completes.  The DC won't set the dequeue pointer
+	 * if the ring is running, and ringing the doorbell starts the
+	 * ring running.
+	 */
+	ep_priv->ep_state |= SET_DEQ_PENDING;
+}
+
+int usbssp_queue_reset_ep(struct usbssp_udc *usbssp_data,
+			  struct usbssp_command *cmd,
+			  unsigned int ep_index,
+			  enum usbssp_ep_reset_type reset_type)
+{
+	u32 trb_slot_id = SLOT_ID_FOR_TRB(usbssp_data->slot_id);
+	u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
+	u32 type = TRB_TYPE(TRB_RESET_EP);
+
+	if (reset_type == EP_SOFT_RESET)
+		type |= TRB_TSP;
+
+	return queue_command(usbssp_data, cmd, 0, 0, 0,
+			trb_slot_id | trb_ep_index | type, false);
+}
+
+/*
+ * Queue an NOP command TRB
+ */
+int usbssp_queue_nop(struct usbssp_udc *usbssp_data,
+		     struct usbssp_command *cmd)
+{
+	return queue_command(usbssp_data, cmd, 0, 0, 0,
+			TRB_TYPE(TRB_CMD_NOOP), false);
+}
+
+/*
+ * Queue a halt endpoint request on the command ring
+ */
+int usbssp_queue_halt_endpoint(struct usbssp_udc *usbssp_data,
+			       struct usbssp_command *cmd,
+			       unsigned int ep_index)
+{
+	u32 trb_slot_id = SLOT_ID_FOR_TRB(usbssp_data->slot_id);
+	u32 trb_ep_index = EP_ID_FOR_TRB(ep_index);
+
+	return queue_command(usbssp_data, cmd, 0, 0, 0,
+			TRB_TYPE(TRB_HALT_ENDPOINT) | trb_slot_id |
+			trb_ep_index, false);
+}
