1 files changed, 39 insertions, 4 deletions

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index c7e3c7142b9d..9d6bb3d730c4 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -284,9 +284,38 @@ static void handle_cmd_completion(struct xhci_hcd *xhci,
         inc_deq(xhci, xhci->cmd_ring, false);
 }
 
+static void handle_port_status(struct xhci_hcd *xhci,
+                union xhci_trb *event)
+{
+        u32 port_id;
+
+        /* Port status change events always have a successful completion code */
+        if (GET_COMP_CODE(event->generic.field[2]) != COMP_SUCCESS) {
+                xhci_warn(xhci, "WARN: xHC returned failed port status event\n");
+                xhci->error_bitmask |= 1 << 8;
+        }
+        /* FIXME: core doesn't care about all port link state changes yet */
+        port_id = GET_PORT_ID(event->generic.field[0]);
+        xhci_dbg(xhci, "Port Status Change Event for port %d\n", port_id);
+
+        /* Update event ring dequeue pointer before dropping the lock */
+        inc_deq(xhci, xhci->event_ring, true);
+        set_hc_event_deq(xhci);
+
+        spin_unlock(&xhci->lock);
+        /* Pass this up to the core */
+        usb_hcd_poll_rh_status(xhci_to_hcd(xhci));
+        spin_lock(&xhci->lock);
+}
+
+/*
+ * This function handles all OS-owned events on the event ring.  It may drop
+ * xhci->lock between event processing (e.g. to pass up port status changes).
+ */
 void handle_event(struct xhci_hcd *xhci)
 {
         union xhci_trb *event;
+        int update_ptrs = 1;
 
         if (!xhci->event_ring || !xhci->event_ring->dequeue) {
                 xhci->error_bitmask |= 1 << 1;
@@ -301,18 +330,24 @@ void handle_event(struct xhci_hcd *xhci)
                 return;
         }
 
-        /* FIXME: Only handles command completion events. */
+        /* FIXME: Handle more event types. */
         switch ((event->event_cmd.flags & TRB_TYPE_BITMASK)) {
         case TRB_TYPE(TRB_COMPLETION):
                 handle_cmd_completion(xhci, &event->event_cmd);
                 break;
+        case TRB_TYPE(TRB_PORT_STATUS):
+                handle_port_status(xhci, event);
+                update_ptrs = 0;
+                break;
         default:
                 xhci->error_bitmask |= 1 << 3;
         }
 
-        /* Update SW and HC event ring dequeue pointer */
-        inc_deq(xhci, xhci->event_ring, true);
-        set_hc_event_deq(xhci);
+        if (update_ptrs) {
+                /* Update SW and HC event ring dequeue pointer */
+                inc_deq(xhci, xhci->event_ring, true);
+                set_hc_event_deq(xhci);
+        }
         /* Are there more items on the event ring? */
         handle_event(xhci);
 }