1 files changed, 26 insertions, 1 deletions

diff --git a/drivers/usb/host/ehci-pci.c b/drivers/usb/host/ehci-pci.c
index 441c26064b44..14fff5714c1e 100644
--- a/drivers/usb/host/ehci-pci.c
+++ b/drivers/usb/host/ehci-pci.c
@@ -228,14 +228,36 @@ static int ehci_pci_reset(struct usb_hcd *hcd)
 static int ehci_pci_suspend(struct usb_hcd *hcd, pm_message_t message)
 {
         struct ehci_hcd         *ehci = hcd_to_ehci(hcd);
+        unsigned long           flags;
+        int                     rc = 0;
 
         if (time_before(jiffies, ehci->next_statechange))
                 msleep(10);
 
+        /* Root hub was already suspended. Disable irq emission and
+         * mark HW unaccessible, bail out if RH has been resumed. Use
+         * the spinlock to properly synchronize with possible pending
+         * RH suspend or resume activity.
+         *
+         * This is still racy as hcd->state is manipulated outside of
+         * any locks =P But that will be a different fix.
+         */
+        spin_lock_irqsave (&ehci->lock, flags);
+        if (hcd->state != HC_STATE_SUSPENDED) {
+                rc = -EINVAL;
+                goto bail;
+        }
+        writel (0, &ehci->regs->intr_enable);
+        (void)readl(&ehci->regs->intr_enable);
+
+        clear_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
+ bail:
+        spin_unlock_irqrestore (&ehci->lock, flags);
+
         // could save FLADJ in case of Vaux power loss
         // ... we'd only use it to handle clock skew
 
-        return 0;
+        return rc;
 }
 
 static int ehci_pci_resume(struct usb_hcd *hcd)
@@ -251,6 +273,9 @@ static int ehci_pci_resume(struct usb_hcd *hcd)
         if (time_before(jiffies, ehci->next_statechange))
                 msleep(100);
 
+        /* Mark hardware accessible again as we are out of D3 state by now */
+        set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
+
         /* If CF is clear, we lost PCI Vaux power and need to restart.  */
         if (readl(&ehci->regs->configured_flag) != FLAG_CF)
                 goto restart;