diff --git a/drivers/isdn/hardware/mISDN/hfcsusb.c b/drivers/isdn/hardware/mISDN/hfcsusb.c
index 8fb7c5dea07f..008a74a1ed44 100644
--- a/drivers/isdn/hardware/mISDN/hfcsusb.c
+++ b/drivers/isdn/hardware/mISDN/hfcsusb.c
@@ -1693,13 +1693,23 @@ hfcsusb_stop_endpoint(struct hfcsusb *hw, int channel)
 static int
 setup_hfcsusb(struct hfcsusb *hw)
 {
+	void *dmabuf = kmalloc(sizeof(u_char), GFP_KERNEL);
 	u_char b;
+	int ret;
 
 	if (debug & DBG_HFC_CALL_TRACE)
 		printk(KERN_DEBUG "%s: %s\n", hw->name, __func__);
 
+	if (!dmabuf)
+		return -ENOMEM;
+
+	ret = read_reg_atomic(hw, HFCUSB_CHIP_ID, dmabuf);
+
+	memcpy(&b, dmabuf, sizeof(u_char));
+	kfree(dmabuf);
+
 	/* check the chip id */
-	if (read_reg_atomic(hw, HFCUSB_CHIP_ID, &b) != 1) {
+	if (ret != 1) {
 		printk(KERN_DEBUG "%s: %s: cannot read chip id\n",
 		       hw->name, __func__);
 		return 1;