hwif = &ide_hwifs[idx[i]];
 
-               if ((hwif->chipset != ide_4drives || !hwif->mate ||
-                    !hwif->mate->present) && ide_hwif_request_regions(hwif)) {
+               if (ide_hwif_request_regions(hwif)) {
                        printk(KERN_ERR "%s: ports already in use, "
                                        "skipping probe\n", hwif->name);
                        continue;
 
 #include <linux/module.h>
 #include <linux/ide.h>
 
+#define DRV_NAME "ide-4drives"
+
 int probe_4drives;
 
 module_param_named(probe, probe_4drives, bool, 0);
 static int __init ide_4drives_init(void)
 {
        ide_hwif_t *hwif, *mate;
+       unsigned long base = 0x1f0, ctl = 0x3f6;
        u8 idx[4] = { 0xff, 0xff, 0xff, 0xff };
        hw_regs_t hw;
 
        if (probe_4drives == 0)
                return -ENODEV;
 
+       if (!request_region(base, 8, DRV_NAME)) {
+               printk(KERN_ERR "%s: I/O resource 0x%lX-0x%lX not free.\n",
+                               DRV_NAME, base, base + 7);
+               return -EBUSY;
+       }
+
+       if (!request_region(ctl, 1, DRV_NAME)) {
+               printk(KERN_ERR "%s: I/O resource 0x%lX not free.\n",
+                               DRV_NAME, ctl);
+               release_region(base, 8);
+               return -EBUSY;
+       }
+
        memset(&hw, 0, sizeof(hw));
 
-       ide_std_init_ports(&hw, 0x1f0, 0x3f6);
+       ide_std_init_ports(&hw, base, ctl);
        hw.irq = 14;
        hw.chipset = ide_4drives;
 
        hwif = ide_find_port();
        if (hwif) {
                ide_init_port_hw(hwif, &hw);
+               hwif->mmio = 1;
                idx[0] = hwif->index;
        }
 
                ide_init_port_hw(mate, &hw);
                mate->drives[0].select.all ^= 0x20;
                mate->drives[1].select.all ^= 0x20;
+               mate->mmio = 1;
                idx[1] = mate->index;
 
                if (hwif) {