xhci: Ensure a command structure points to the correct trb on the command ring

[firefly-linux-kernel-4.4.55.git] / drivers / usb / host / xhci-ring.c

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index aaa2906f7b782aeb8c06aee17de0f56961a02f8f..9ac9672d4498fe2550c2169e8fd46d49dca1ef18 100644 (file)
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -123,6 +123,16 @@ static int enqueue_is_link_trb(struct xhci_ring *ring)
        return TRB_TYPE_LINK_LE32(link->control);
 }
 
+union xhci_trb *xhci_find_next_enqueue(struct xhci_ring *ring)
+{
+       /* Enqueue pointer can be left pointing to the link TRB,
+        * we must handle that
+        */
+       if (TRB_TYPE_LINK_LE32(ring->enqueue->link.control))
+               return ring->enq_seg->next->trbs;
+       return ring->enqueue;
+}
+
 /* 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.