shpchp_poll_mode = 1;
 #endif
 
-       shpchp_wq = create_singlethread_workqueue("shpchpd");
-       if (!shpchp_wq)
-               return -ENOMEM;
-
        retval = pci_register_driver(&shpc_driver);
        dbg("%s: pci_register_driver = %d\n", __FUNCTION__, retval);
        info(DRIVER_DESC " version: " DRIVER_VERSION "\n");
-       if (retval) {
-               destroy_workqueue(shpchp_wq);
-       }
        return retval;
 }
 
 {
        dbg("unload_shpchpd()\n");
        pci_unregister_driver(&shpc_driver);
-       destroy_workqueue(shpchp_wq);
        info(DRIVER_DESC " version: " DRIVER_VERSION " unloaded\n");
 }
 
 
 static int ctlr_seq_num = 0;   /* Controller sequenc # */
 static spinlock_t list_lock;
 
+static atomic_t shpchp_num_controllers = ATOMIC_INIT(0);
+
 static irqreturn_t shpc_isr(int IRQ, void *dev_id, struct pt_regs *regs);
 
 static void start_int_poll_timer(struct php_ctlr_state_s *php_ctlr, int seconds);
 
        kfree(php_ctlr);
 
+       /*
+        * If this is the last controller to be released, destroy the
+        * shpchpd work queue
+        */
+       if (atomic_dec_and_test(&shpchp_num_controllers))
+               destroy_workqueue(shpchp_wq);
+
 DBG_LEAVE_ROUTINE
                          
 }
 
        ctlr_seq_num++;
 
+       /*
+        * If this is the first controller to be initialized,
+        * initialize the shpchpd work queue
+        */
+       if (atomic_add_return(1, &shpchp_num_controllers) == 1) {
+               shpchp_wq = create_singlethread_workqueue("shpchpd");
+               if (!shpchp_wq)
+                       return -ENOMEM;
+       }
+
        /*
         * Unmask all event interrupts of all slots
         */