diff --git a/drivers/isdn/hardware/mISDN/mISDNipac.c b/drivers/isdn/hardware/mISDN/mISDNipac.c
index ccd7d851be26..a77eea594b69 100644
--- a/drivers/isdn/hardware/mISDN/mISDNipac.c
+++ b/drivers/isdn/hardware/mISDN/mISDNipac.c
@@ -754,10 +754,10 @@ dbusy_timer_handler(struct isac_hw *isac)
 }
 
 static int
-open_dchannel(struct isac_hw *isac, struct channel_req *rq)
+open_dchannel_caller(struct isac_hw *isac, struct channel_req *rq, void *caller)
 {
 	pr_debug("%s: %s dev(%d) open from %p\n", isac->name, __func__,
-		 isac->dch.dev.id, __builtin_return_address(1));
+		 isac->dch.dev.id, caller);
 	if (rq->protocol != ISDN_P_TE_S0)
 		return -EINVAL;
 	if (rq->adr.channel == 1)
@@ -771,6 +771,12 @@ open_dchannel(struct isac_hw *isac, struct channel_req *rq)
 	return 0;
 }
 
+static int
+open_dchannel(struct isac_hw *isac, struct channel_req *rq)
+{
+	return open_dchannel_caller(isac, rq, __builtin_return_address(0));
+}
+
 static const char *ISACVer[] =
 {"2086/2186 V1.1", "2085 B1", "2085 B2",
  "2085 V2.3"};
@@ -1548,7 +1554,7 @@ ipac_dctrl(struct mISDNchannel *ch, u32 cmd, void *arg)
 	case OPEN_CHANNEL:
 		rq = arg;
 		if (rq->protocol == ISDN_P_TE_S0)
-			err = open_dchannel(isac, rq);
+			err = open_dchannel_caller(isac, rq, __builtin_return_address(0));
 		else
 			err = open_bchannel(ipac, rq);
 		if (err)
diff --git a/drivers/isdn/hardware/mISDN/w6692.c b/drivers/isdn/hardware/mISDN/w6692.c
index de69f6828c76..741675525b53 100644
--- a/drivers/isdn/hardware/mISDN/w6692.c
+++ b/drivers/isdn/hardware/mISDN/w6692.c
@@ -1176,10 +1176,10 @@ w6692_l1callback(struct dchannel *dch, u32 cmd)
 }
 
 static int
-open_dchannel(struct w6692_hw *card, struct channel_req *rq)
+open_dchannel(struct w6692_hw *card, struct channel_req *rq, void *caller)
 {
 	pr_debug("%s: %s dev(%d) open from %p\n", card->name, __func__,
-		 card->dch.dev.id, __builtin_return_address(1));
+		 card->dch.dev.id, caller);
 	if (rq->protocol != ISDN_P_TE_S0)
 		return -EINVAL;
 	if (rq->adr.channel == 1)
@@ -1207,7 +1207,7 @@ w6692_dctrl(struct mISDNchannel *ch, u32 cmd, void *arg)
 	case OPEN_CHANNEL:
 		rq = arg;
 		if (rq->protocol == ISDN_P_TE_S0)
-			err = open_dchannel(card, rq);
+			err = open_dchannel(card, rq, __builtin_return_address(0));
 		else
 			err = open_bchannel(card, rq);
 		if (err)