mutex_unlock(&ide_cfg_mtx);
 }
 
+static ide_hwif_t *ide_ports[MAX_HWIFS];
+
 void ide_remove_port_from_hwgroup(ide_hwif_t *hwif)
 {
        ide_hwgroup_t *hwgroup = hwif->hwgroup;
 
+       ide_ports[hwif->index] = NULL;
+
        spin_lock_irq(&ide_lock);
        /*
         * Remove us from the hwgroup, and free
         * Group up with any other hwifs that share our irq(s).
         */
        for (index = 0; index < MAX_HWIFS; index++) {
-               ide_hwif_t *h = &ide_hwifs[index];
-               if (h->hwgroup) {  /* scan only initialized hwif's */
+               ide_hwif_t *h = ide_ports[index];
+
+               if (h && h->hwgroup) {  /* scan only initialized ports */
                        if (hwif->irq == h->irq) {
                                hwif->sharing_irq = h->sharing_irq = 1;
                                if (hwif->chipset != ide_pci ||
                hwgroup->timer.data = (unsigned long) hwgroup;
        }
 
+       ide_ports[hwif->index] = hwif;
+
        /*
         * Allocate the irq, if not already obtained for another hwif
         */