p = &desc->action;
        if ((old = *p) != NULL) {
                /* Can't share interrupts unless both agree to */
-               if (!(old->flags & new->flags & SA_SHIRQ)) {
-                       spin_unlock_irqrestore(&desc->lock,flags);
-                       return -EBUSY;
-               }
+               if (!(old->flags & new->flags & SA_SHIRQ))
+                       goto mismatch;
+
+#if defined(ARCH_HAS_IRQ_PER_CPU) && defined(SA_PERCPU_IRQ)
+               /* All handlers must agree on per-cpuness */
+               if ((old->flags & IRQ_PER_CPU) != (new->flags & IRQ_PER_CPU))
+                       goto mismatch;
+#endif
 
                /* add new interrupt at end of irq queue */
                do {
        }
 
        *p = new;
-
+#if defined(ARCH_HAS_IRQ_PER_CPU) && defined(SA_PERCPU_IRQ)
+       if (new->flags & SA_PERCPU_IRQ)
+               desc->status |= IRQ_PER_CPU;
+#endif
        if (!shared) {
                desc->depth = 0;
                desc->status &= ~(IRQ_DISABLED | IRQ_AUTODETECT |
        register_handler_proc(irq, new);
 
        return 0;
+
+mismatch:
+       spin_unlock_irqrestore(&desc->lock, flags);
+       printk(KERN_ERR "%s: irq handler mismatch\n", __FUNCTION__);
+       dump_stack();
+       return -EBUSY;
 }
 
 /**