#define aac_phys_to_logical(x)  ((x)+1)
 #define aac_logical_to_phys(x)  ((x)?(x)-1:0)
 
+/*
+ * These macros are for keeping track of
+ * character device state.
+ */
+#define AAC_CHARDEV_UNREGISTERED       (-1)
+#define AAC_CHARDEV_NEEDS_REINIT       (-2)
+
 /* #define AAC_DETAILED_STATUS_INFO */
 
 struct diskparm
 
 
 static DEFINE_MUTEX(aac_mutex);
 static LIST_HEAD(aac_devices);
-static int aac_cfg_major = -1;
+static int aac_cfg_major = AAC_CHARDEV_UNREGISTERED;
 char aac_driver_version[] = AAC_DRIVER_FULL_VERSION;
 
 /*
        else if (aac->max_msix > 1)
                pci_disable_msix(aac->pdev);
 }
+static void aac_init_char(void)
+{
+       aac_cfg_major = register_chrdev(0, "aac", &aac_cfg_fops);
+       if (aac_cfg_major < 0) {
+               pr_err("aacraid: unable to register \"aac\" device.\n");
+       }
+}
 
 static int aac_probe_one(struct pci_dev *pdev, const struct pci_device_id *id)
 {
        shost->max_cmd_len = 16;
        shost->use_cmd_list = 1;
 
+       if (aac_cfg_major == AAC_CHARDEV_NEEDS_REINIT)
+               aac_init_char();
+
        aac = (struct aac_dev *)shost->hostdata;
        aac->base_start = pci_resource_start(pdev, 0);
        aac->scsi_host_ptr = shost;
        pci_disable_device(pdev);
        if (list_empty(&aac_devices)) {
                unregister_chrdev(aac_cfg_major, "aac");
-               aac_cfg_major = -1;
+               aac_cfg_major = AAC_CHARDEV_NEEDS_REINIT;
        }
 }
 
        if (error < 0)
                return error;
 
-       aac_cfg_major = register_chrdev( 0, "aac", &aac_cfg_fops);
-       if (aac_cfg_major < 0) {
-               printk(KERN_WARNING
-                       "aacraid: unable to register \"aac\" device.\n");
-       }
+       aac_init_char();
+
 
        return 0;
 }