sbp2: check for ARM failure

Sbp2 did not check for successful registration of the lower address range
when CONFIG_IEEE1394_SBP2_PHYS_DMA was set. If hpsb_register_addrspace
failed, a "login timed-out" would occur which is misleading. Now sbp2 logs
a sensible error message.
Signed-off-by: NStefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: NJody McIntyre <scjody@modernduck.com>

drivers/ieee1394/sbp2.c

@@ -749,9 +749,13 @@ static struct scsi_id_instance_data *sbp2_alloc_device(struct unit_directory *ud
 
 #ifdef CONFIG_IEEE1394_SBP2_PHYS_DMA
 		/* Handle data movement if physical dma is not
-		 * enabled/supportedon host controller */
-		hpsb_register_addrspace(&sbp2_highlevel, ud->ne->host, &sbp2_physdma_ops,
-					0x0ULL, 0xfffffffcULL);
+		 * enabled or not supported on host controller */
+		if (!hpsb_register_addrspace(&sbp2_highlevel, ud->ne->host,
+					     &sbp2_physdma_ops,
+					     0x0ULL, 0xfffffffcULL)) {
+			SBP2_ERR("failed to register lower 4GB address range");
+			goto failed_alloc;
+		}
 #endif
 	}