1 files changed, 41 insertions, 63 deletions

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 60fb52ae864b..abed30b82905 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -364,32 +364,6 @@ static void ring_doorbell_for_active_rings(struct xhci_hcd *xhci,
 	}
 }
 
-/*
- * Find the segment that trb is in.  Start searching in start_seg.
- * If we must move past a segment that has a link TRB with a toggle cycle state
- * bit set, then we will toggle the value pointed at by cycle_state.
- */
-static struct xhci_segment *find_trb_seg(
-		struct xhci_segment *start_seg,
-		union xhci_trb	*trb, int *cycle_state)
-{
-	struct xhci_segment *cur_seg = start_seg;
-	struct xhci_generic_trb *generic_trb;
-
-	while (cur_seg->trbs > trb ||
-			&cur_seg->trbs[TRBS_PER_SEGMENT - 1] < trb) {
-		generic_trb = &cur_seg->trbs[TRBS_PER_SEGMENT - 1].generic;
-		if (generic_trb->field[3] & cpu_to_le32(LINK_TOGGLE))
-			*cycle_state ^= 0x1;
-		cur_seg = cur_seg->next;
-		if (cur_seg == start_seg)
-			/* Looped over the entire list.  Oops! */
-			return NULL;
-	}
-	return cur_seg;
-}
-
-
 static struct xhci_ring *xhci_triad_to_transfer_ring(struct xhci_hcd *xhci,
 		unsigned int slot_id, unsigned int ep_index,
 		unsigned int stream_id)
@@ -459,9 +433,12 @@ void xhci_find_new_dequeue_state(struct xhci_hcd *xhci,
 	struct xhci_virt_device *dev = xhci->devs[slot_id];
 	struct xhci_virt_ep *ep = &dev->eps[ep_index];
 	struct xhci_ring *ep_ring;
-	struct xhci_generic_trb *trb;
+	struct xhci_segment *new_seg;
+	union xhci_trb *new_deq;
 	dma_addr_t addr;
 	u64 hw_dequeue;
+	bool cycle_found = false;
+	bool td_last_trb_found = false;
 
 	ep_ring = xhci_triad_to_transfer_ring(xhci, slot_id,
 			ep_index, stream_id);
@@ -486,45 +463,45 @@ void xhci_find_new_dequeue_state(struct xhci_hcd *xhci,
 		hw_dequeue = le64_to_cpu(ep_ctx->deq);
 	}
 
-	/* Find virtual address and segment of hardware dequeue pointer */
-	state->new_deq_seg = ep_ring->deq_seg;
-	state->new_deq_ptr = ep_ring->dequeue;
-	while (xhci_trb_virt_to_dma(state->new_deq_seg, state->new_deq_ptr)
-			!= (dma_addr_t)(hw_dequeue & ~0xf)) {
-		next_trb(xhci, ep_ring, &state->new_deq_seg,
-					&state->new_deq_ptr);
-		if (state->new_deq_ptr == ep_ring->dequeue) {
-			WARN_ON(1);
-			return;
-		}
-	}
+	new_seg = ep_ring->deq_seg;
+	new_deq = ep_ring->dequeue;
+	state->new_cycle_state = hw_dequeue & 0x1;
+
 	/*
-	 * Find cycle state for last_trb, starting at old cycle state of
-	 * hw_dequeue. If there is only one segment ring, find_trb_seg() will
-	 * return immediately and cannot toggle the cycle state if this search
-	 * wraps around, so add one more toggle manually in that case.
+	 * 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.
 	 */
-	state->new_cycle_state = hw_dequeue & 0x1;
-	if (ep_ring->first_seg == ep_ring->first_seg->next &&
-			cur_td->last_trb < state->new_deq_ptr)
-		state->new_cycle_state ^= 0x1;
+	do {
+		if (!cycle_found && xhci_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;
 
-	state->new_deq_ptr = cur_td->last_trb;
-	xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb,
-			"Finding segment containing last TRB in TD.");
-	state->new_deq_seg = find_trb_seg(state->new_deq_seg,
-			state->new_deq_ptr, &state->new_cycle_state);
-	if (!state->new_deq_seg) {
-		WARN_ON(1);
-		return;
-	}
+		if (cycle_found &&
+		    TRB_TYPE_LINK_LE32(new_deq->generic.field[3]) &&
+		    new_deq->generic.field[3] & cpu_to_le32(LINK_TOGGLE))
+			state->new_cycle_state ^= 0x1;
+
+		next_trb(xhci, ep_ring, &new_seg, &new_deq);
+
+		/* Search wrapped around, bail out */
+		if (new_deq == ep->ring->dequeue) {
+			xhci_err(xhci, "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);
 
-	/* Increment to find next TRB after last_trb. Cycle if appropriate. */
-	trb = &state->new_deq_ptr->generic;
-	if (TRB_TYPE_LINK_LE32(trb->field[3]) &&
-	    (trb->field[3] & cpu_to_le32(LINK_TOGGLE)))
-		state->new_cycle_state ^= 0x1;
-	next_trb(xhci, ep_ring, &state->new_deq_seg, &state->new_deq_ptr);
+	state->new_deq_seg = new_seg;
+	state->new_deq_ptr = new_deq;
 
 	/* Don't update the ring cycle state for the producer (us). */
 	xhci_dbg_trace(xhci, trace_xhci_dbg_cancel_urb,
@@ -2487,7 +2464,8 @@ static int handle_tx_event(struct xhci_hcd *xhci,
 		 * last TRB of the previous TD. The command completion handle
 		 * will take care the rest.
 		 */
-		if (!event_seg && trb_comp_code == COMP_STOP_INVAL) {
+		if (!event_seg && (trb_comp_code == COMP_STOP ||
+				   trb_comp_code == COMP_STOP_INVAL)) {
 			ret = 0;
 			goto cleanup;
 		}