1 files changed, 23 insertions, 0 deletions

diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c
index ac57f538f957..4e51343ddffc 100644
--- a/drivers/usb/host/xhci-mem.c
+++ b/drivers/usb/host/xhci-mem.c
@@ -1601,6 +1601,29 @@ static int xhci_check_trb_in_td_math(struct xhci_hcd *xhci, gfp_t mem_flags)
         return 0;
 }
 
+static void xhci_set_hc_event_deq(struct xhci_hcd *xhci)
+{
+        u64 temp;
+        dma_addr_t deq;
+
+        deq = xhci_trb_virt_to_dma(xhci->event_ring->deq_seg,
+                        xhci->event_ring->dequeue);
+        if (deq == 0 && !in_interrupt())
+                xhci_warn(xhci, "WARN something wrong with SW event ring "
+                                "dequeue ptr.\n");
+        /* Update HC event ring dequeue pointer */
+        temp = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
+        temp &= ERST_PTR_MASK;
+        /* Don't clear the EHB bit (which is RW1C) because
+         * there might be more events to service.
+         */
+        temp &= ~ERST_EHB;
+        xhci_dbg(xhci, "// Write event ring dequeue pointer, "
+                        "preserving EHB bit\n");
+        xhci_write_64(xhci, ((u64) deq & (u64) ~ERST_PTR_MASK) | temp,
+                        &xhci->ir_set->erst_dequeue);
+}
+
 
 int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags)
 {