1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/usb/host/ehci-hub.c b/drivers/usb/host/ehci-hub.c
index 8a28dae8a375..84e792d71c22 100644
--- a/drivers/usb/host/ehci-hub.c
+++ b/drivers/usb/host/ehci-hub.c
@@ -603,6 +603,7 @@ ehci_hub_status_data (struct usb_hcd *hcd, char *buf)
         u32             mask;
         int             ports, i, retval = 1;
         unsigned long   flags;
+        u32             ppcd = 0;
 
         /* if !USB_SUSPEND, root hub timers won't get shut down ... */
         if (!HC_IS_RUNNING(hcd->state))
@@ -632,7 +633,15 @@ ehci_hub_status_data (struct usb_hcd *hcd, char *buf)
 
         /* port N changes (bit N)? */
         spin_lock_irqsave (&ehci->lock, flags);
+
+        /* get per-port change detect bits */
+        if (ehci->has_ppcd)
+                ppcd = ehci_readl(ehci, &ehci->regs->status) >> 16;
+
         for (i = 0; i < ports; i++) {
+                /* leverage per-port change bits feature */
+                if (ehci->has_ppcd && !(ppcd & (1 << i)))
+                        continue;
                 temp = ehci_readl(ehci, &ehci->regs->port_status [i]);
 
                 /*