Revert "USB: EHCI: fix performance regression"

This reverts commit fa38dfcc56b5f6cce787f9aaa5d1830509213802.

It wasn't really a regression and David and Alan are still working
through the issues reported.

Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

2 files changed, 8 insertions, 10 deletions

diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 3e3c5d3ea0ad..369a8a5ea7bb 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -84,8 +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/100)        /* async qh unlink delay */
-#define EHCI_SHRINK_UFRAMES     (10*8)          /* same value in uframes */
+#define EHCI_SHRINK_JIFFIES     (HZ/200)        /* 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 5200481deb27..b85b54160cda 100644
--- a/drivers/usb/host/ehci-q.c
+++ b/drivers/usb/host/ehci-q.c
@@ -1116,7 +1116,8 @@ static void scan_async (struct ehci_hcd *ehci)
         struct ehci_qh          *qh;
         enum ehci_timer_action  action = TIMER_IO_WATCHDOG;
 
-        ehci->stamp = ehci_readl(ehci, &ehci->regs->frame_index);
+        if (!++(ehci->stamp))
+                ehci->stamp++;
         timer_action_done (ehci, TIMER_ASYNC_SHRINK);
 rescan:
         qh = ehci->async->qh_next.qh;
@@ -1147,14 +1148,12 @@ rescan:
                          * doesn't stay idle for long.
                          * (plus, avoids some kind of re-activation race.)
                          */
-                        if (list_empty(&qh->qtd_list) &&
-                                        qh->qh_state == QH_STATE_LINKED) {
-                                if (!ehci->reclaim &&
-                                    ((ehci->stamp - qh->stamp) & 8191) >=
-                                                EHCI_SHRINK_UFRAMES)
-                                        start_unlink_async(ehci, qh);
-                                else
+                        if (list_empty (&qh->qtd_list)) {
+                                if (qh->stamp == ehci->stamp)
                                         action = TIMER_ASYNC_SHRINK;
+                                else if (!ehci->reclaim
+                                            && qh->qh_state == QH_STATE_LINKED)
+                                        start_unlink_async (ehci, qh);
                         }
 
                         qh = qh->qh_next.qh;