3 files changed, 14 insertions, 10 deletions

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 369a8a5ea7bb..d9d53f289caf 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -84,7 +84,7 @@ static const char	hcd_name [] = "ehci_hcd";
 #define EHCI_IAA_MSECS          10              /* arbitrary */
 #define EHCI_IO_JIFFIES         (HZ/10)         /* io watchdog > irq_thresh */
 #define EHCI_ASYNC_JIFFIES      (HZ/20)         /* async idle timeout */
-#define EHCI_SHRINK_JIFFIES     (HZ/200)        /* async qh unlink delay */
+#define EHCI_SHRINK_FRAMES      5               /* async qh unlink delay */
 
 /* Initial IRQ latency:  faster than hw default */
 static int log2_irq_thresh = 0;         // 0 to 6
diff --git a/drivers/usb/host/ehci-q.c b/drivers/usb/host/ehci-q.c
index b85b54160cda..2622b6596d7c 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -1116,8 +1116,7 @@ static void scan_async (struct ehci_hcd *ehci)
         struct ehci_qh          *qh;
         enum ehci_timer_action  action = TIMER_IO_WATCHDOG;
 
-        if (!++(ehci->stamp))
-                ehci->stamp++;
+        ehci->stamp = ehci_readl(ehci, &ehci->regs->frame_index);
         timer_action_done (ehci, TIMER_ASYNC_SHRINK);
 rescan:
         qh = ehci->async->qh_next.qh;
@@ -1142,18 +1141,20 @@ rescan:
                                 }
                         }
 
-                        /* unlink idle entries, reducing HC PCI usage as well
+                        /* unlink idle entries, reducing DMA usage as well
                          * as HCD schedule-scanning costs.  delay for any qh
                          * we just scanned, there's a not-unusual case that it
                          * doesn't stay idle for long.
                          * (plus, avoids some kind of re-activation race.)
                          */
-                        if (list_empty (&qh->qtd_list)) {
-                                if (qh->stamp == ehci->stamp)
+                        if (list_empty(&qh->qtd_list)
+                                        && qh->qh_state == QH_STATE_LINKED) {
+                                if (!ehci->reclaim
+                                        && ((ehci->stamp - qh->stamp) & 0x1fff)
+                                                >= (EHCI_SHRINK_FRAMES * 8))
+                                        start_unlink_async(ehci, qh);
+                                else
                                         action = TIMER_ASYNC_SHRINK;
-                                else if (!ehci->reclaim
-                                            && qh->qh_state == QH_STATE_LINKED)
-                                        start_unlink_async (ehci, qh);
                         }
 
                         qh = qh->qh_next.qh;
diff --git a/drivers/usb/host/ehci.h b/drivers/usb/host/ehci.h
index 90245fd8bac4..5799298364fb 100644
--- a/drivers/usb/host/ehci.h
+++ b/drivers/usb/host/ehci.h
@@ -198,7 +198,10 @@ timer_action (struct ehci_hcd *ehci, enum ehci_timer_action action)
                         break;
                 // case TIMER_ASYNC_SHRINK:
                 default:
-                        t = EHCI_SHRINK_JIFFIES;
+                        /* add a jiffie since we synch against the
+                         * 8 KHz uframe counter.
+                         */
+                        t = DIV_ROUND_UP(EHCI_SHRINK_FRAMES * HZ, 1000) + 1;
                         break;
                 }
                 mod_timer(&ehci->watchdog, t + jiffies);