From c84ed39e601ff69d93e0ad81d92cb7234ad5d4cd Mon Sep 17 00:00:00 2001

From: Hans de Goede <hdegoede@redhat.com>

Date: Mon, 10 Sep 2012 12:44:10 +0200

Subject: [PATCH] ehci: Fix interrupts stopping when Interrupt Threshold

 Control is 8

If Interrupt Threshold Control is 8 or a multiple of 8, then

s->usbsts_frindex can become exactly 0x4000, at which point

(s->usbsts_frindex > s->frindex) will never become true, as

s->usbsts_frindex will not be lowered / reset in this case.

This patch fixes this.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

(cherry picked from commit ffa1f2e088eb7e3d57f2fc35f21e7bdb23e592c5)

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>

---

 hw/usb/hcd-ehci.c | 2 +-

 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/usb/hcd-ehci.c b/hw/usb/hcd-ehci.c

index f5ba8e1..54273d7 100644

--- a/hw/usb/hcd-ehci.c

+++ b/hw/usb/hcd-ehci.c

@@ -2413,7 +2413,7 @@ static void ehci_update_frindex(EHCIState *ehci, int frames)

         if (ehci->frindex == 0x00004000) {

             ehci_raise_irq(ehci, USBSTS_FLR);

             ehci->frindex = 0;

-            if (ehci->usbsts_frindex > 0x00004000) {

+            if (ehci->usbsts_frindex >= 0x00004000) {

                 ehci->usbsts_frindex -= 0x00004000;

             } else {

                 ehci->usbsts_frindex = 0;

-- 

1.7.12.1