1 files changed, 13 insertions, 10 deletions

diff --git a/drivers/usb/host/ohci-hcd.c b/drivers/usb/host/ohci-hcd.c
index 704f33fdd2f1..ecfe800fd720 100644
--- a/drivers/usb/host/ohci-hcd.c
+++ b/drivers/usb/host/ohci-hcd.c
@@ -732,24 +732,27 @@ static irqreturn_t ohci_irq (struct usb_hcd *hcd)
         struct ohci_regs __iomem *regs = ohci->regs;
         int                     ints;
 
-        /* we can eliminate a (slow) ohci_readl()
-         * if _only_ WDH caused this irq
+        /* Read interrupt status (and flush pending writes).  We ignore the
+         * optimization of checking the LSB of hcca->done_head; it doesn't
+         * work on all systems (edge triggering for OHCI can be a factor).
          */
-        if ((ohci->hcca->done_head != 0)
-                        && ! (hc32_to_cpup (ohci, &ohci->hcca->done_head)
-                                & 0x01)) {
-                ints =  OHCI_INTR_WDH;
+        ints = ohci_readl(ohci, &regs->intrstatus);
 
-        /* cardbus/... hardware gone before remove() */
-        } else if ((ints = ohci_readl (ohci, &regs->intrstatus)) == ~(u32)0) {
+        /* Check for an all 1's result which is a typical consequence
+         * of dead, unclocked, or unplugged (CardBus...) devices
+         */
+        if (ints == ~(u32)0) {
                 disable (ohci);
                 ohci_dbg (ohci, "device removed!\n");
                 return IRQ_HANDLED;
+        }
+
+        /* We only care about interrupts that are enabled */
+        ints &= ohci_readl(ohci, &regs->intrenable);
 
         /* interrupt for some other device? */
-        } else if ((ints &= ohci_readl (ohci, &regs->intrenable)) == 0) {
+        if (ints == 0)
                 return IRQ_NOTMINE;
-        }
 
         if (ints & OHCI_INTR_UE) {
                 // e.g. due to PCI Master/Target Abort