1 files changed, 37 insertions, 10 deletions

diff --git a/drivers/usb/core/hcd.c b/drivers/usb/core/hcd.c
index 09a53e7f3327..42a436478b78 100644
--- a/drivers/usb/core/hcd.c
+++ b/drivers/usb/core/hcd.c
@@ -924,6 +924,15 @@ static int register_root_hub(struct usb_hcd *hcd)
         return retval;
 }
 
+void usb_enable_root_hub_irq (struct usb_bus *bus)
+{
+        struct usb_hcd *hcd;
+
+        hcd = container_of (bus, struct usb_hcd, self);
+        if (hcd->driver->hub_irq_enable && hcd->state != HC_STATE_HALT)
+                hcd->driver->hub_irq_enable (hcd);
+}
+
 
 /*-------------------------------------------------------------------------*/
 
@@ -1684,19 +1693,30 @@ EXPORT_SYMBOL_GPL(usb_bus_start_enum);
 irqreturn_t usb_hcd_irq (int irq, void *__hcd)
 {
         struct usb_hcd          *hcd = __hcd;
-        int                     start = hcd->state;
+        unsigned long           flags;
+        irqreturn_t             rc;
 
-        if (unlikely(start == HC_STATE_HALT ||
-            !test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags)))
-                return IRQ_NONE;
-        if (hcd->driver->irq (hcd) == IRQ_NONE)
-                return IRQ_NONE;
+        /* IRQF_DISABLED doesn't work correctly with shared IRQs
+         * when the first handler doesn't use it.  So let's just
+         * assume it's never used.
+         */
+        local_irq_save(flags);
 
-        set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
+        if (unlikely(hcd->state == HC_STATE_HALT ||
+                     !test_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags))) {
+                rc = IRQ_NONE;
+        } else if (hcd->driver->irq(hcd) == IRQ_NONE) {
+                rc = IRQ_NONE;
+        } else {
+                set_bit(HCD_FLAG_SAW_IRQ, &hcd->flags);
+
+                if (unlikely(hcd->state == HC_STATE_HALT))
+                        usb_hc_died(hcd);
+                rc = IRQ_HANDLED;
+        }
 
-        if (unlikely(hcd->state == HC_STATE_HALT))
-                usb_hc_died (hcd);
-        return IRQ_HANDLED;
+        local_irq_restore(flags);
+        return rc;
 }
 
 /*-------------------------------------------------------------------------*/
@@ -1860,6 +1880,13 @@ int usb_add_hcd(struct usb_hcd *hcd,
 
         /* enable irqs just before we start the controller */
         if (hcd->driver->irq) {
+
+                /* IRQF_DISABLED doesn't work as advertised when used together
+                 * with IRQF_SHARED. As usb_hcd_irq() will always disable
+                 * interrupts we can remove it here.
+                 */
+                irqflags &= ~IRQF_DISABLED;
+
                 snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
                                 hcd->driver->description, hcd->self.busnum);
                 if ((retval = request_irq(irqnum, &usb_hcd_irq, irqflags,