1 files changed, 19 insertions, 13 deletions

diff --git a/arch/i386/kernel/io_apic.c b/arch/i386/kernel/io_apic.c
index 2424cc9c7b3d..6a3875f81a0a 100644
--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -1227,26 +1227,32 @@ static u8 irq_vector[NR_IRQ_VECTORS] __read_mostly = { FIRST_DEVICE_VECTOR , 0 }
 
 static int __assign_irq_vector(int irq)
 {
-        static int current_vector = FIRST_DEVICE_VECTOR, offset = 0;
-        int vector;
+        static int current_vector = FIRST_DEVICE_VECTOR, current_offset = 0;
+        int vector, offset, i;
 
         BUG_ON((unsigned)irq >= NR_IRQ_VECTORS);
 
         if (irq_vector[irq] > 0)
                 return irq_vector[irq];
 
-        current_vector += 8;
-        if (current_vector == SYSCALL_VECTOR)
-                current_vector += 8;
-
-        if (current_vector >= FIRST_SYSTEM_VECTOR) {
-                offset++;
-                if (!(offset % 8))
-                        return -ENOSPC;
-                current_vector = FIRST_DEVICE_VECTOR + offset;
-        }
-
         vector = current_vector;
+        offset = current_offset;
+next:
+        vector += 8;
+        if (vector >= FIRST_SYSTEM_VECTOR) {
+                offset = (offset + 1) % 8;
+                vector = FIRST_DEVICE_VECTOR + offset;
+        }
+        if (vector == current_vector)
+                return -ENOSPC;
+        if (vector == SYSCALL_VECTOR)
+                goto next;
+        for (i = 0; i < NR_IRQ_VECTORS; i++)
+                if (irq_vector[i] == vector)
+                        goto next;
+
+        current_vector = vector;
+        current_offset = offset;
         irq_vector[irq] = vector;
 
         return vector;