xHCI: store ring's type

When allocate a ring, store its type - four transfer types for endpoint,
TYPE_STREAM for stream transfer, and TYPE_COMMAND/TYPE_EVENT for xHCI host.

This helps to get rid of three bool function parameters: link_trbs, isoc
and consumer.

Signed-off-by: Andiry Xu <andiry.xu@amd.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Tested-by: Paul Zimmerman <Paul.Zimmerman@synopsys.com>

drivers/usb/host/xhci-mem.c

@@ -73,14 +73,14 @@ static void xhci_segment_free(struct xhci_hcd *xhci, struct xhci_segment *seg)
  * related flags, such as End TRB, Toggle Cycle, and no snoop.
  */
 static void xhci_link_segments(struct xhci_hcd *xhci, struct xhci_segment *prev,
-		struct xhci_segment *next, bool link_trbs, bool isoc)
+		struct xhci_segment *next, enum xhci_ring_type type)
 {
 	u32 val;
 
 	if (!prev || !next)
 		return;
 	prev->next = next;
-	if (link_trbs) {
+	if (type != TYPE_EVENT) {
 		prev->trbs[TRBS_PER_SEGMENT-1].link.segment_ptr =
 			cpu_to_le64(next->dma);
 
@@ -91,7 +91,8 @@ static void xhci_link_segments(struct xhci_hcd *xhci, struct xhci_segment *prev,
 		/* Always set the chain bit with 0.95 hardware */
 		/* Set chain bit for isoc rings on AMD 0.96 host */
 		if (xhci_link_trb_quirk(xhci) ||
-				(isoc && (xhci->quirks & XHCI_AMD_0x96_HOST)))
+				(type == TYPE_ISOC &&
+				 (xhci->quirks & XHCI_AMD_0x96_HOST)))
 			val |= TRB_CHAIN;
 		prev->trbs[TRBS_PER_SEGMENT-1].link.control = cpu_to_le32(val);
 	}
@@ -144,7 +145,7 @@ static void xhci_initialize_ring_info(struct xhci_ring *ring)
  * See section 4.9.1 and figures 15 and 16.
  */
 static struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci,
-		unsigned int num_segs, bool link_trbs, bool isoc, gfp_t flags)
+		unsigned int num_segs, enum xhci_ring_type type, gfp_t flags)
 {
 	struct xhci_ring	*ring;
 	struct xhci_segment	*prev;
@@ -154,6 +155,7 @@ static struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci,
 		return NULL;
 
 	INIT_LIST_HEAD(&ring->td_list);
+	ring->type = type;
 	if (num_segs == 0)
 		return ring;
 
@@ -169,14 +171,15 @@ static struct xhci_ring *xhci_ring_alloc(struct xhci_hcd *xhci,
 		next = xhci_segment_alloc(xhci, flags);
 		if (!next)
 			goto fail;
-		xhci_link_segments(xhci, prev, next, link_trbs, isoc);
+		xhci_link_segments(xhci, prev, next, type);
 
 		prev = next;
 		num_segs--;
 	}
-	xhci_link_segments(xhci, prev, ring->first_seg, link_trbs, isoc);
+	xhci_link_segments(xhci, prev, ring->first_seg, type);
 
-	if (link_trbs) {
+	/* Only event ring does not use link TRB */
+	if (type != TYPE_EVENT) {
 		/* See section 4.9.2.1 and 6.4.4.1 */
 		prev->trbs[TRBS_PER_SEGMENT-1].link.control |=
 			cpu_to_le32(LINK_TOGGLE);
@@ -217,16 +220,17 @@ void xhci_free_or_cache_endpoint_ring(struct xhci_hcd *xhci,
  * pointers to the beginning of the ring.
  */
 static void xhci_reinit_cached_ring(struct xhci_hcd *xhci,
-		struct xhci_ring *ring, bool isoc)
+			struct xhci_ring *ring, enum xhci_ring_type type)
 {
 	struct xhci_segment	*seg = ring->first_seg;
 	do {
 		memset(seg->trbs, 0,
 				sizeof(union xhci_trb)*TRBS_PER_SEGMENT);
 		/* All endpoint rings have link TRBs */
-		xhci_link_segments(xhci, seg, seg->next, 1, isoc);
+		xhci_link_segments(xhci, seg, seg->next, type);
 		seg = seg->next;
 	} while (seg != ring->first_seg);
+	ring->type = type;
 	xhci_initialize_ring_info(ring);
 	/* td list should be empty since all URBs have been cancelled,
 	 * but just in case...
@@ -528,7 +532,7 @@ struct xhci_stream_info *xhci_alloc_stream_info(struct xhci_hcd *xhci,
 	 */
 	for (cur_stream = 1; cur_stream < num_streams; cur_stream++) {
 		stream_info->stream_rings[cur_stream] =
-			xhci_ring_alloc(xhci, 1, true, false, mem_flags);
+			xhci_ring_alloc(xhci, 1, TYPE_STREAM, mem_flags);
 		cur_ring = stream_info->stream_rings[cur_stream];
 		if (!cur_ring)
 			goto cleanup_rings;
@@ -862,7 +866,7 @@ int xhci_alloc_virt_device(struct xhci_hcd *xhci, int slot_id,
 	}
 
 	/* Allocate endpoint 0 ring */
-	dev->eps[0].ring = xhci_ring_alloc(xhci, 1, true, false, flags);
+	dev->eps[0].ring = xhci_ring_alloc(xhci, 1, TYPE_CTRL, flags);
 	if (!dev->eps[0].ring)
 		goto fail;
 
@@ -1300,11 +1304,13 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
 	struct xhci_ring *ep_ring;
 	unsigned int max_packet;
 	unsigned int max_burst;
+	enum xhci_ring_type type;
 	u32 max_esit_payload;
 
 	ep_index = xhci_get_endpoint_index(&ep->desc);
 	ep_ctx = xhci_get_ep_ctx(xhci, virt_dev->in_ctx, ep_index);
 
+	type = usb_endpoint_type(&ep->desc);
 	/* Set up the endpoint ring */
 	/*
 	 * Isochronous endpoint ring needs bigger size because one isoc URB
@@ -1314,10 +1320,10 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
 	 */
 	if (usb_endpoint_xfer_isoc(&ep->desc))
 		virt_dev->eps[ep_index].new_ring =
-			xhci_ring_alloc(xhci, 8, true, true, mem_flags);
+			xhci_ring_alloc(xhci, 8, type, mem_flags);
 	else
 		virt_dev->eps[ep_index].new_ring =
-			xhci_ring_alloc(xhci, 1, true, false, mem_flags);
+			xhci_ring_alloc(xhci, 1, type, mem_flags);
 	if (!virt_dev->eps[ep_index].new_ring) {
 		/* Attempt to use the ring cache */
 		if (virt_dev->num_rings_cached == 0)
@@ -1327,7 +1333,7 @@ int xhci_endpoint_init(struct xhci_hcd *xhci,
 		virt_dev->ring_cache[virt_dev->num_rings_cached] = NULL;
 		virt_dev->num_rings_cached--;
 		xhci_reinit_cached_ring(xhci, virt_dev->eps[ep_index].new_ring,
-			usb_endpoint_xfer_isoc(&ep->desc) ? true : false);
+					type);
 	}
 	virt_dev->eps[ep_index].skip = false;
 	ep_ring = virt_dev->eps[ep_index].new_ring;
@@ -2235,7 +2241,7 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
 		goto fail;
 
 	/* Set up the command ring to have one segments for now. */
-	xhci->cmd_ring = xhci_ring_alloc(xhci, 1, true, false, flags);
+	xhci->cmd_ring = xhci_ring_alloc(xhci, 1, TYPE_COMMAND, flags);
 	if (!xhci->cmd_ring)
 		goto fail;
 	xhci_dbg(xhci, "Allocated command ring at %p\n", xhci->cmd_ring);
@@ -2266,7 +2272,7 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
 	 * the event ring segment table (ERST).  Section 4.9.3.
 	 */
 	xhci_dbg(xhci, "// Allocating event ring\n");
-	xhci->event_ring = xhci_ring_alloc(xhci, ERST_NUM_SEGS, false, false,
+	xhci->event_ring = xhci_ring_alloc(xhci, ERST_NUM_SEGS, TYPE_EVENT,
 						flags);
 	if (!xhci->event_ring)
 		goto fail;

drivers/usb/host/xhci-ring.c

@@ -143,7 +143,7 @@ static void next_trb(struct xhci_hcd *xhci,
  * 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.
  */
-static void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer)
+static void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring)
 {
 	union xhci_trb *next = ++(ring->dequeue);
 	unsigned long long addr;
@@ -153,7 +153,8 @@ static void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer
 	 * the end of an event ring segment (which doesn't have link TRBS)
 	 */
 	while (last_trb(xhci, ring, ring->deq_seg, next)) {
-		if (consumer && last_trb_on_last_seg(xhci, ring, ring->deq_seg, next)) {
+		if (ring->type == TYPE_EVENT &&	last_trb_on_last_seg(xhci,
+				ring, ring->deq_seg, next)) {
 			ring->cycle_state = (ring->cycle_state ? 0 : 1);
 		}
 		ring->deq_seg = ring->deq_seg->next;
@@ -181,7 +182,7 @@ static void inc_deq(struct xhci_hcd *xhci, struct xhci_ring *ring, bool consumer
  *			prepare_transfer()?
  */
 static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring,
-		bool consumer, bool more_trbs_coming, bool isoc)
+			bool more_trbs_coming)
 {
 	u32 chain;
 	union xhci_trb *next;
@@ -195,35 +196,35 @@ static void inc_enq(struct xhci_hcd *xhci, struct xhci_ring *ring,
 	 * the end of an event ring segment (which doesn't have link TRBS)
 	 */
 	while (last_trb(xhci, ring, ring->enq_seg, next)) {
-		if (!consumer) {
-			if (ring != xhci->event_ring) {
-				/*
-				 * 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;
+		if (ring->type != TYPE_EVENT) {
+			/*
+			 * 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;
 
-				/* If we're not dealing with 0.95 hardware or
-				 * isoc rings on AMD 0.96 host,
-				 * carry over the chain bit of the previous TRB
-				 * (which may mean the chain bit is cleared).
-				 */
-				if (!(isoc && (xhci->quirks & XHCI_AMD_0x96_HOST))
+			/* If we're not dealing with 0.95 hardware or
+			 * isoc rings on AMD 0.96 host,
+			 * carry over the chain bit of the previous TRB
+			 * (which may mean the chain bit is cleared).
+			 */
+			if (!(ring->type == TYPE_ISOC &&
+					(xhci->quirks & XHCI_AMD_0x96_HOST))
 						&& !xhci_link_trb_quirk(xhci)) {
-					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);
+				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 (last_trb_on_last_seg(xhci, ring, ring->enq_seg, next)) {
 				ring->cycle_state = (ring->cycle_state ? 0 : 1);
@@ -1185,7 +1186,7 @@ bandwidth_change:
 		xhci->error_bitmask |= 1 << 6;
 		break;
 	}
-	inc_deq(xhci, xhci->cmd_ring, false);
+	inc_deq(xhci, xhci->cmd_ring);
 }
 
 static void handle_vendor_event(struct xhci_hcd *xhci,
@@ -1398,7 +1399,7 @@ static void handle_port_status(struct xhci_hcd *xhci,
 
 cleanup:
 	/* Update event ring dequeue pointer before dropping the lock */
-	inc_deq(xhci, xhci->event_ring, true);
+	inc_deq(xhci, xhci->event_ring);
 
 	/* Don't make the USB core poll the roothub if we got a bad port status
 	 * change event.  Besides, at that point we can't tell which roothub
@@ -1593,8 +1594,8 @@ static int finish_td(struct xhci_hcd *xhci, struct xhci_td *td,
 		} else {
 			/* Update ring dequeue pointer */
 			while (ep_ring->dequeue != td->last_trb)
-				inc_deq(xhci, ep_ring, false);
-			inc_deq(xhci, ep_ring, false);
+				inc_deq(xhci, ep_ring);
+			inc_deq(xhci, ep_ring);
 		}
 
 td_cleanup:
@@ -1842,8 +1843,8 @@ static int skip_isoc_td(struct xhci_hcd *xhci, struct xhci_td *td,
 
 	/* Update ring dequeue pointer */
 	while (ep_ring->dequeue != td->last_trb)
-		inc_deq(xhci, ep_ring, false);
-	inc_deq(xhci, ep_ring, false);
+		inc_deq(xhci, ep_ring);
+	inc_deq(xhci, ep_ring);
 
 	return finish_td(xhci, td, NULL, event, ep, status, true);
 }
@@ -2230,7 +2231,7 @@ cleanup:
 		 * Will roll back to continue process missed tds.
 		 */
 		if (trb_comp_code == COMP_MISSED_INT || !ep->skip) {
-			inc_deq(xhci, xhci->event_ring, true);
+			inc_deq(xhci, xhci->event_ring);
 		}
 
 		if (ret) {
@@ -2345,7 +2346,7 @@ static int xhci_handle_event(struct xhci_hcd *xhci)
 
 	if (update_ptrs)
 		/* Update SW event ring dequeue pointer */
-		inc_deq(xhci, xhci->event_ring, true);
+		inc_deq(xhci, xhci->event_ring);
 
 	/* Are there more items on the event ring?  Caller will call us again to
 	 * check.
@@ -2461,7 +2462,7 @@ irqreturn_t xhci_msi_irq(int irq, struct usb_hcd *hcd)
  *			prepare_transfer()?
  */
 static void queue_trb(struct xhci_hcd *xhci, struct xhci_ring *ring,
-		bool consumer, bool more_trbs_coming, bool isoc,
+		bool more_trbs_coming,
 		u32 field1, u32 field2, u32 field3, u32 field4)
 {
 	struct xhci_generic_trb *trb;
@@ -2471,7 +2472,7 @@ static void queue_trb(struct xhci_hcd *xhci, struct xhci_ring *ring,
 	trb->field[1] = cpu_to_le32(field2);
 	trb->field[2] = cpu_to_le32(field3);
 	trb->field[3] = cpu_to_le32(field4);
-	inc_enq(xhci, ring, consumer, more_trbs_coming, isoc);
+	inc_enq(xhci, ring, more_trbs_coming);
 }
 
 /*
@@ -2479,7 +2480,7 @@ static void queue_trb(struct xhci_hcd *xhci, struct xhci_ring *ring,
  * FIXME allocate segments if the ring is full.
  */
 static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
-		u32 ep_state, unsigned int num_trbs, bool isoc, gfp_t mem_flags)
+		u32 ep_state, unsigned int num_trbs, gfp_t mem_flags)
 {
 	/* Make sure the endpoint has been added to xHC schedule */
 	switch (ep_state) {
@@ -2524,8 +2525,9 @@ static int prepare_ring(struct xhci_hcd *xhci, struct xhci_ring *ep_ring,
 			/* If we're not dealing with 0.95 hardware or isoc rings
 			 * on AMD 0.96 host, clear the chain bit.
 			 */
-			if (!xhci_link_trb_quirk(xhci) && !(isoc &&
-					(xhci->quirks & XHCI_AMD_0x96_HOST)))
+			if (!xhci_link_trb_quirk(xhci) &&
+					!(ring->type == TYPE_ISOC &&
+					 (xhci->quirks & XHCI_AMD_0x96_HOST)))
 				next->link.control &= cpu_to_le32(~TRB_CHAIN);
 			else
 				next->link.control |= cpu_to_le32(TRB_CHAIN);
@@ -2553,7 +2555,6 @@ static int prepare_transfer(struct xhci_hcd *xhci,
 		unsigned int num_trbs,
 		struct urb *urb,
 		unsigned int td_index,
-		bool isoc,
 		gfp_t mem_flags)
 {
 	int ret;
@@ -2571,7 +2572,7 @@ static int prepare_transfer(struct xhci_hcd *xhci,
 
 	ret = prepare_ring(xhci, ep_ring,
 			   le32_to_cpu(ep_ctx->ep_info) & EP_STATE_MASK,
-			   num_trbs, isoc, mem_flags);
+			   num_trbs, mem_flags);
 	if (ret)
 		return ret;
 
@@ -2781,7 +2782,7 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 
 	trb_buff_len = prepare_transfer(xhci, xhci->devs[slot_id],
 			ep_index, urb->stream_id,
-			num_trbs, urb, 0, false, mem_flags);
+			num_trbs, urb, 0, mem_flags);
 	if (trb_buff_len < 0)
 		return trb_buff_len;
 
@@ -2869,7 +2870,7 @@ static int queue_bulk_sg_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 			more_trbs_coming = true;
 		else
 			more_trbs_coming = false;
-		queue_trb(xhci, ep_ring, false, more_trbs_coming, false,
+		queue_trb(xhci, ep_ring, more_trbs_coming,
 				lower_32_bits(addr),
 				upper_32_bits(addr),
 				length_field,
@@ -2951,7 +2952,7 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 
 	ret = prepare_transfer(xhci, xhci->devs[slot_id],
 			ep_index, urb->stream_id,
-			num_trbs, urb, 0, false, mem_flags);
+			num_trbs, urb, 0, mem_flags);
 	if (ret < 0)
 		return ret;
 
@@ -3023,7 +3024,7 @@ int xhci_queue_bulk_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 			more_trbs_coming = true;
 		else
 			more_trbs_coming = false;
-		queue_trb(xhci, ep_ring, false, more_trbs_coming, false,
+		queue_trb(xhci, ep_ring, more_trbs_coming,
 				lower_32_bits(addr),
 				upper_32_bits(addr),
 				length_field,
@@ -3080,7 +3081,7 @@ int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 		num_trbs++;
 	ret = prepare_transfer(xhci, xhci->devs[slot_id],
 			ep_index, urb->stream_id,
-			num_trbs, urb, 0, false, mem_flags);
+			num_trbs, urb, 0, mem_flags);
 	if (ret < 0)
 		return ret;
 
@@ -3113,7 +3114,7 @@ int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 		}
 	}
 
-	queue_trb(xhci, ep_ring, false, true, false,
+	queue_trb(xhci, ep_ring, true,
 		  setup->bRequestType | setup->bRequest << 8 | le16_to_cpu(setup->wValue) << 16,
 		  le16_to_cpu(setup->wIndex) | le16_to_cpu(setup->wLength) << 16,
 		  TRB_LEN(8) | TRB_INTR_TARGET(0),
@@ -3133,7 +3134,7 @@ int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 	if (urb->transfer_buffer_length > 0) {
 		if (setup->bRequestType & USB_DIR_IN)
 			field |= TRB_DIR_IN;
-		queue_trb(xhci, ep_ring, false, true, false,
+		queue_trb(xhci, ep_ring, true,
 				lower_32_bits(urb->transfer_dma),
 				upper_32_bits(urb->transfer_dma),
 				length_field,
@@ -3149,7 +3150,7 @@ int xhci_queue_ctrl_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 		field = 0;
 	else
 		field = TRB_DIR_IN;
-	queue_trb(xhci, ep_ring, false, false, false,
+	queue_trb(xhci, ep_ring, false,
 			0,
 			0,
 			TRB_INTR_TARGET(0),
@@ -3289,8 +3290,7 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 		trbs_per_td = count_isoc_trbs_needed(xhci, urb, i);
 
 		ret = prepare_transfer(xhci, xhci->devs[slot_id], ep_index,
-				urb->stream_id, trbs_per_td, urb, i, true,
-				mem_flags);
+				urb->stream_id, trbs_per_td, urb, i, mem_flags);
 		if (ret < 0) {
 			if (i == 0)
 				return ret;
@@ -3360,7 +3360,7 @@ static int xhci_queue_isoc_tx(struct xhci_hcd *xhci, gfp_t mem_flags,
 				remainder |
 				TRB_INTR_TARGET(0);
 
-			queue_trb(xhci, ep_ring, false, more_trbs_coming, true,
+			queue_trb(xhci, ep_ring, more_trbs_coming,
 				lower_32_bits(addr),
 				upper_32_bits(addr),
 				length_field,
@@ -3443,7 +3443,7 @@ int xhci_queue_isoc_tx_prepare(struct xhci_hcd *xhci, gfp_t mem_flags,
 	 * Do not insert any td of the urb to the ring if the check failed.
 	 */
 	ret = prepare_ring(xhci, ep_ring, le32_to_cpu(ep_ctx->ep_info) & EP_STATE_MASK,
-			   num_trbs, true, mem_flags);
+			   num_trbs, mem_flags);
 	if (ret)
 		return ret;
 
@@ -3502,7 +3502,7 @@ static int queue_command(struct xhci_hcd *xhci, u32 field1, u32 field2,
 		reserved_trbs++;
 
 	ret = prepare_ring(xhci, xhci->cmd_ring, EP_STATE_RUNNING,
-			reserved_trbs, false, GFP_ATOMIC);
+			reserved_trbs, GFP_ATOMIC);
 	if (ret < 0) {
 		xhci_err(xhci, "ERR: No room for command on command ring\n");
 		if (command_must_succeed)
@@ -3510,8 +3510,8 @@ static int queue_command(struct xhci_hcd *xhci, u32 field1, u32 field2,
 					"unfailable commands failed.\n");
 		return ret;
 	}
-	queue_trb(xhci, xhci->cmd_ring, false, false, false, field1, field2,
-			field3,	field4 | xhci->cmd_ring->cycle_state);
+	queue_trb(xhci, xhci->cmd_ring, false, field1, field2, field3,
+			field4 | xhci->cmd_ring->cycle_state);
 	return 0;
 }
 

drivers/usb/host/xhci.h

@@ -1250,6 +1250,16 @@ struct xhci_dequeue_state {
 	int new_cycle_state;
 };
 
+enum xhci_ring_type {
+	TYPE_CTRL = 0,
+	TYPE_ISOC,
+	TYPE_BULK,
+	TYPE_INTR,
+	TYPE_STREAM,
+	TYPE_COMMAND,
+	TYPE_EVENT,
+};
+
 struct xhci_ring {
 	struct xhci_segment	*first_seg;
 	union  xhci_trb		*enqueue;
@@ -1266,6 +1276,7 @@ struct xhci_ring {
 	 */
 	u32			cycle_state;
 	unsigned int		stream_id;
+	enum xhci_ring_type	type;
 	bool			last_td_was_short;
 };