1 files changed, 37 insertions, 13 deletions

diff --git a/drivers/usb/host/xhci-ring.c b/drivers/usb/host/xhci-ring.c
index 3b962ba5ef08..7dfd17707d53 100644
--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -1184,7 +1184,6 @@ static void handle_port_status(struct xhci_hcd *xhci,
 
         /* Update event ring dequeue pointer before dropping the lock */
         inc_deq(xhci, xhci->event_ring, true);
-        xhci_set_hc_event_deq(xhci);
 
         spin_unlock(&xhci->lock);
         /* Pass this up to the core */
@@ -1924,7 +1923,6 @@ cleanup:
                  */
                 if (trb_comp_code == COMP_MISSED_INT || !ep->skip) {
                         inc_deq(xhci, xhci->event_ring, true);
-                        xhci_set_hc_event_deq(xhci);
                 }
 
                 if (ret) {
@@ -2022,11 +2020,10 @@ static void xhci_handle_event(struct xhci_hcd *xhci)
                 return;
         }
 
-        if (update_ptrs) {
-                /* Update SW and HC event ring dequeue pointer */
+        if (update_ptrs)
+                /* Update SW event ring dequeue pointer */
                 inc_deq(xhci, xhci->event_ring, true);
-                xhci_set_hc_event_deq(xhci);
-        }
+
         /* Are there more items on the event ring? */
         xhci_handle_event(xhci);
 }
@@ -2042,6 +2039,8 @@ irqreturn_t xhci_irq(struct usb_hcd *hcd)
         u32 status, irq_pending;
         union xhci_trb *trb;
         u64 temp_64;
+        union xhci_trb *event_ring_deq;
+        dma_addr_t deq;
 
         spin_lock(&xhci->lock);
         trb = xhci->event_ring->dequeue;
@@ -2090,18 +2089,43 @@ hw_died:
         irq_pending |= 0x3;
         xhci_writel(xhci, irq_pending, &xhci->ir_set->irq_pending);
 
-        if (xhci->xhc_state & XHCI_STATE_DYING)
+        if (xhci->xhc_state & XHCI_STATE_DYING) {
                 xhci_dbg(xhci, "xHCI dying, ignoring interrupt. "
                                 "Shouldn't IRQs be disabled?\n");
-        else
-                /* FIXME this should be a delayed service routine
-                 * that clears the EHB.
+                /* Clear the event handler busy flag (RW1C);
+                 * the event ring should be empty.
                  */
-                xhci_handle_event(xhci);
+                temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
+                xhci_write_64(xhci, temp_64 | ERST_EHB,
+                                &xhci->ir_set->erst_dequeue);
+                spin_unlock(&xhci->lock);
+
+                return IRQ_HANDLED;
+        }
+
+        event_ring_deq = xhci->event_ring->dequeue;
+        /* FIXME this should be a delayed service routine
+         * that clears the EHB.
+         */
+        xhci_handle_event(xhci);
 
-        /* Clear the event handler busy flag (RW1C); event ring is empty. */
         temp_64 = xhci_read_64(xhci, &xhci->ir_set->erst_dequeue);
-        xhci_write_64(xhci, temp_64 | ERST_EHB, &xhci->ir_set->erst_dequeue);
+        /* If necessary, update the HW's version of the event ring deq ptr. */
+        if (event_ring_deq != xhci->event_ring->dequeue) {
+                deq = xhci_trb_virt_to_dma(xhci->event_ring->deq_seg,
+                                xhci->event_ring->dequeue);
+                if (deq == 0)
+                        xhci_warn(xhci, "WARN something wrong with SW event "
+                                        "ring dequeue ptr.\n");
+                /* Update HC event ring dequeue pointer */
+                temp_64 &= ERST_PTR_MASK;
+                temp_64 |= ((u64) deq & (u64) ~ERST_PTR_MASK);
+        }
+
+        /* Clear the event handler busy flag (RW1C); event ring is empty. */
+        temp_64 |= ERST_EHB;
+        xhci_write_64(xhci, temp_64, &xhci->ir_set->erst_dequeue);
+
         spin_unlock(&xhci->lock);
 
         return IRQ_HANDLED;