static int __init build_detail_arrays(void)
 {
        unsigned long ptr;
-       int i, scal_detail_size, rio_detail_size;
+       unsigned numnodes, i;
+       int scal_detail_size, rio_detail_size;
 
-       if (rio_table_hdr->num_scal_dev > MAX_NUMNODES){
+       numnodes = rio_table_hdr->num_scal_dev;
+       if (numnodes > MAX_NUMNODES){
                printk(KERN_WARNING
                        "Calgary: MAX_NUMNODES too low! Defined as %d, "
                        "but system has %d nodes.\n",
-                       MAX_NUMNODES, rio_table_hdr->num_scal_dev);
+                       MAX_NUMNODES, numnodes);
                return -ENODEV;
        }
 
        }
 
        ptr = ((unsigned long)rio_table_hdr) + 3;
-       for (i = 0; i < rio_table_hdr->num_scal_dev;
-                   i++, ptr += scal_detail_size)
+       for (i = 0; i < numnodes; i++, ptr += scal_detail_size)
                scal_devs[i] = (struct scal_detail *)ptr;
 
        for (i = 0; i < rio_table_hdr->num_rio_dev;