diff --git a/qemu/hw/piix_pci.c b/qemu/hw/piix_pci.c
old mode 100644
new mode 100755
index 8c00f0d..ce2a5c7
--- a/qemu/hw/piix_pci.c
+++ b/qemu/hw/piix_pci.c
@@ -207,7 +207,8 @@ static int pci_irq_levels[4];
 static void piix3_set_irq(qemu_irq *pic, int irq_num, int level)
 {
     int i, pic_irq, pic_level;
-
+    
+    piix3_dev->config[0x60 + irq_num] &= ~0x80;   // enable bit
     pci_irq_levels[irq_num] = level;
 
     /* now we change the pic irq level according to the piix irq mappings */