diff --git a/drivers/isdn/mISDN/l1oip.h b/drivers/isdn/mISDN/l1oip.h
index 7ea10db20e3a6..48133d0228120 100644
--- a/drivers/isdn/mISDN/l1oip.h
+++ b/drivers/isdn/mISDN/l1oip.h
@@ -59,6 +59,7 @@ struct l1oip {
 	int			bundle;		/* bundle channels in one frm */
 	int			codec;		/* codec to use for transmis. */
 	int			limit;		/* limit number of bchannels */
+	bool			shutdown;	/* if card is released */
 
 	/* timer */
 	struct timer_list	keep_tl;
diff --git a/drivers/isdn/mISDN/l1oip_core.c b/drivers/isdn/mISDN/l1oip_core.c
index 072bb5e36c184..be6eb29410764 100644
--- a/drivers/isdn/mISDN/l1oip_core.c
+++ b/drivers/isdn/mISDN/l1oip_core.c
@@ -289,7 +289,7 @@ l1oip_socket_send(struct l1oip *hc, u8 localcodec, u8 channel, u32 chanmask,
 	p = frame;
 
 	/* restart timer */
-	if (time_before(hc->keep_tl.expires, jiffies + 5 * HZ))
+	if (time_before(hc->keep_tl.expires, jiffies + 5 * HZ) && !hc->shutdown)
 		mod_timer(&hc->keep_tl, jiffies + L1OIP_KEEPALIVE * HZ);
 	else
 		hc->keep_tl.expires = jiffies + L1OIP_KEEPALIVE * HZ;
@@ -615,7 +615,9 @@ l1oip_socket_parse(struct l1oip *hc, struct sockaddr_in *sin, u8 *buf, int len)
 		goto multiframe;
 
 	/* restart timer */
-	if (time_before(hc->timeout_tl.expires, jiffies + 5 * HZ) || !hc->timeout_on) {
+	if ((time_before(hc->timeout_tl.expires, jiffies + 5 * HZ) ||
+	     !hc->timeout_on) &&
+	    !hc->shutdown) {
 		hc->timeout_on = 1;
 		mod_timer(&hc->timeout_tl, jiffies + L1OIP_TIMEOUT * HZ);
 	} else /* only adjust timer */
@@ -1246,11 +1248,10 @@ release_card(struct l1oip *hc)
 {
 	int	ch;
 
-	if (timer_pending(&hc->keep_tl))
-		del_timer(&hc->keep_tl);
+	hc->shutdown = true;
 
-	if (timer_pending(&hc->timeout_tl))
-		del_timer(&hc->timeout_tl);
+	del_timer_sync(&hc->keep_tl);
+	del_timer_sync(&hc->timeout_tl);
 
 	cancel_work_sync(&hc->workq);