isdn/gigaset: correct CAPI connection state storage

CAPI applications can handle several connections in parallel,
so one connection state per application isn't sufficient.
Store the connection state in the channel structure instead.

Impact: bugfix
Signed-off-by: Tilman Schmidt <tilman@imap.cc>
Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 180 insertions, 53 deletions

diff --git a/drivers/isdn/gigaset/capi.c b/drivers/isdn/gigaset/capi.c
index 665673f4d667..6fbe8999c419 100644
--- a/drivers/isdn/gigaset/capi.c
+++ b/drivers/isdn/gigaset/capi.c
@@ -70,7 +70,7 @@
 #define MAX_NUMBER_DIGITS 20
 #define MAX_FMT_IE_LEN 20
 
-/* values for gigaset_capi_appl.connected */
+/* values for bcs->apconnstate */
 #define APCONN_NONE	0	/* inactive/listening */
 #define APCONN_SETUP	1	/* connecting */
 #define APCONN_ACTIVE	2	/* B channel up */
@@ -84,7 +84,6 @@ struct gigaset_capi_appl {
 	u16 nextMessageNumber;
 	u32 listenInfoMask;
 	u32 listenCIPmask;
-	int connected;
 };
 
 /* CAPI specific controller data structure */
@@ -384,7 +383,7 @@ void gigaset_skb_sent(struct bc_state *bcs, struct sk_buff *dskb)
 	}
 
 	/* don't send further B3 messages if disconnected */
-	if (ap->connected < APCONN_ACTIVE) {
+	if (bcs->apconnstate < APCONN_ACTIVE) {
 		gig_dbg(DEBUG_LLDATA, "disconnected, discarding ack");
 		return;
 	}
@@ -428,7 +427,7 @@ void gigaset_skb_rcvd(struct bc_state *bcs, struct sk_buff *skb)
 	}
 
 	/* don't send further B3 messages if disconnected */
-	if (ap->connected < APCONN_ACTIVE) {
+	if (bcs->apconnstate < APCONN_ACTIVE) {
 		gig_dbg(DEBUG_LLDATA, "disconnected, discarding data");
 		dev_kfree_skb_any(skb);
 		return;
@@ -500,6 +499,7 @@ int gigaset_isdn_icall(struct at_state_t *at_state)
 	u32 actCIPmask;
 	struct sk_buff *skb;
 	unsigned int msgsize;
+	unsigned long flags;
 	int i;
 
 	/*
@@ -624,7 +624,14 @@ int gigaset_isdn_icall(struct at_state_t *at_state)
 		format_ie(iif->hcmsg.CalledPartyNumber));
 
 	/* scan application list for matching listeners */
-	bcs->ap = NULL;
+	spin_lock_irqsave(&bcs->aplock, flags);
+	if (bcs->ap != NULL || bcs->apconnstate != APCONN_NONE) {
+		dev_warn(cs->dev, "%s: channel not properly cleared (%p/%d)\n",
+			 __func__, bcs->ap, bcs->apconnstate);
+		bcs->ap = NULL;
+		bcs->apconnstate = APCONN_NONE;
+	}
+	spin_unlock_irqrestore(&bcs->aplock, flags);
 	actCIPmask = 1 | (1 << iif->hcmsg.CIPValue);
 	list_for_each_entry(ap, &iif->appls, ctrlist)
 		if (actCIPmask & ap->listenCIPmask) {
@@ -642,10 +649,12 @@ int gigaset_isdn_icall(struct at_state_t *at_state)
 			dump_cmsg(DEBUG_CMD, __func__, &iif->hcmsg);
 
 			/* add to listeners on this B channel, update state */
+			spin_lock_irqsave(&bcs->aplock, flags);
 			ap->bcnext = bcs->ap;
 			bcs->ap = ap;
 			bcs->chstate |= CHS_NOTIFY_LL;
-			ap->connected = APCONN_SETUP;
+			bcs->apconnstate = APCONN_SETUP;
+			spin_unlock_irqrestore(&bcs->aplock, flags);
 
 			/* emit message */
 			capi_ctr_handle_message(&iif->ctr, ap->id, skb);
@@ -670,7 +679,7 @@ static void send_disconnect_ind(struct bc_state *bcs,
 	struct gigaset_capi_ctr *iif = cs->iif;
 	struct sk_buff *skb;
 
-	if (ap->connected == APCONN_NONE)
+	if (bcs->apconnstate == APCONN_NONE)
 		return;
 
 	capi_cmsg_header(&iif->hcmsg, ap->id, CAPI_DISCONNECT, CAPI_IND,
@@ -684,7 +693,6 @@ static void send_disconnect_ind(struct bc_state *bcs,
 	}
 	capi_cmsg2message(&iif->hcmsg, __skb_put(skb, CAPI_DISCONNECT_IND_LEN));
 	dump_cmsg(DEBUG_CMD, __func__, &iif->hcmsg);
-	ap->connected = APCONN_NONE;
 	capi_ctr_handle_message(&iif->ctr, ap->id, skb);
 }
 
@@ -701,9 +709,9 @@ static void send_disconnect_b3_ind(struct bc_state *bcs,
 	struct sk_buff *skb;
 
 	/* nothing to do if no logical connection active */
-	if (ap->connected < APCONN_ACTIVE)
+	if (bcs->apconnstate < APCONN_ACTIVE)
 		return;
-	ap->connected = APCONN_SETUP;
+	bcs->apconnstate = APCONN_SETUP;
 
 	capi_cmsg_header(&iif->hcmsg, ap->id, CAPI_DISCONNECT_B3, CAPI_IND,
 			 ap->nextMessageNumber++,
@@ -730,14 +738,25 @@ void gigaset_isdn_connD(struct bc_state *bcs)
 {
 	struct cardstate *cs = bcs->cs;
 	struct gigaset_capi_ctr *iif = cs->iif;
-	struct gigaset_capi_appl *ap = bcs->ap;
+	struct gigaset_capi_appl *ap;
 	struct sk_buff *skb;
 	unsigned int msgsize;
+	unsigned long flags;
 
+	spin_lock_irqsave(&bcs->aplock, flags);
+	ap = bcs->ap;
 	if (!ap) {
+		spin_unlock_irqrestore(&bcs->aplock, flags);
 		dev_err(cs->dev, "%s: no application\n", __func__);
 		return;
 	}
+	if (bcs->apconnstate == APCONN_NONE) {
+		spin_unlock_irqrestore(&bcs->aplock, flags);
+		dev_warn(cs->dev, "%s: application %u not connected\n",
+			 __func__, ap->id);
+		return;
+	}
+	spin_unlock_irqrestore(&bcs->aplock, flags);
 	while (ap->bcnext) {
 		/* this should never happen */
 		dev_warn(cs->dev, "%s: dropping extra application %u\n",
@@ -746,11 +765,6 @@ void gigaset_isdn_connD(struct bc_state *bcs)
 				    CapiCallGivenToOtherApplication);
 		ap->bcnext = ap->bcnext->bcnext;
 	}
-	if (ap->connected == APCONN_NONE) {
-		dev_warn(cs->dev, "%s: application %u not connected\n",
-			 __func__, ap->id);
-		return;
-	}
 
 	/* prepare CONNECT_ACTIVE_IND message
 	 * Note: LLC not supported by device
@@ -788,17 +802,24 @@ void gigaset_isdn_connD(struct bc_state *bcs)
 void gigaset_isdn_hupD(struct bc_state *bcs)
 {
 	struct gigaset_capi_appl *ap;
+	unsigned long flags;
 
 	/*
 	 * ToDo: pass on reason code reported by device
 	 * (requires ev-layer state machine extension to collect
 	 * ZCAU device reply)
 	 */
-	for (ap = bcs->ap; ap != NULL; ap = ap->bcnext) {
+	spin_lock_irqsave(&bcs->aplock, flags);
+	while (bcs->ap != NULL) {
+		ap = bcs->ap;
+		bcs->ap = ap->bcnext;
+		spin_unlock_irqrestore(&bcs->aplock, flags);
 		send_disconnect_b3_ind(bcs, ap);
 		send_disconnect_ind(bcs, ap, 0);
+		spin_lock_irqsave(&bcs->aplock, flags);
 	}
-	bcs->ap = NULL;
+	bcs->apconnstate = APCONN_NONE;
+	spin_unlock_irqrestore(&bcs->aplock, flags);
 }
 
 /**
@@ -812,24 +833,21 @@ void gigaset_isdn_connB(struct bc_state *bcs)
 {
 	struct cardstate *cs = bcs->cs;
 	struct gigaset_capi_ctr *iif = cs->iif;
-	struct gigaset_capi_appl *ap = bcs->ap;
+	struct gigaset_capi_appl *ap;
 	struct sk_buff *skb;
+	unsigned long flags;
 	unsigned int msgsize;
 	u8 command;
 
+	spin_lock_irqsave(&bcs->aplock, flags);
+	ap = bcs->ap;
 	if (!ap) {
+		spin_unlock_irqrestore(&bcs->aplock, flags);
 		dev_err(cs->dev, "%s: no application\n", __func__);
 		return;
 	}
-	while (ap->bcnext) {
-		/* this should never happen */
-		dev_warn(cs->dev, "%s: dropping extra application %u\n",
-			 __func__, ap->bcnext->id);
-		send_disconnect_ind(bcs, ap->bcnext,
-				    CapiCallGivenToOtherApplication);
-		ap->bcnext = ap->bcnext->bcnext;
-	}
-	if (!ap->connected) {
+	if (!bcs->apconnstate) {
+		spin_unlock_irqrestore(&bcs->aplock, flags);
 		dev_warn(cs->dev, "%s: application %u not connected\n",
 			 __func__, ap->id);
 		return;
@@ -841,13 +859,26 @@ void gigaset_isdn_connB(struct bc_state *bcs)
 	 * CONNECT_B3_ACTIVE_IND in reply to CONNECT_B3_RESP
 	 * Parameters in both cases always: NCCI = 1, NCPI empty
 	 */
-	if (ap->connected >= APCONN_ACTIVE) {
+	if (bcs->apconnstate >= APCONN_ACTIVE) {
 		command = CAPI_CONNECT_B3_ACTIVE;
 		msgsize = CAPI_CONNECT_B3_ACTIVE_IND_BASELEN;
 	} else {
 		command = CAPI_CONNECT_B3;
 		msgsize = CAPI_CONNECT_B3_IND_BASELEN;
 	}
+	bcs->apconnstate = APCONN_ACTIVE;
+
+	spin_unlock_irqrestore(&bcs->aplock, flags);
+
+	while (ap->bcnext) {
+		/* this should never happen */
+		dev_warn(cs->dev, "%s: dropping extra application %u\n",
+			 __func__, ap->bcnext->id);
+		send_disconnect_ind(bcs, ap->bcnext,
+				    CapiCallGivenToOtherApplication);
+		ap->bcnext = ap->bcnext->bcnext;
+	}
+
 	capi_cmsg_header(&iif->hcmsg, ap->id, command, CAPI_IND,
 			 ap->nextMessageNumber++,
 			 iif->ctr.cnr | ((bcs->channel + 1) << 8) | (1 << 16));
@@ -858,7 +889,6 @@ void gigaset_isdn_connB(struct bc_state *bcs)
 	}
 	capi_cmsg2message(&iif->hcmsg, __skb_put(skb, msgsize));
 	dump_cmsg(DEBUG_CMD, __func__, &iif->hcmsg);
-	ap->connected = APCONN_ACTIVE;
 	capi_ctr_handle_message(&iif->ctr, ap->id, skb);
 }
 
@@ -964,6 +994,61 @@ static void gigaset_register_appl(struct capi_ctr *ctr, u16 appl,
 	ap->rp = *rp;
 
 	list_add(&ap->ctrlist, &iif->appls);
+	dev_info(cs->dev, "application %u registered\n", ap->id);
+}
+
+/*
+ * remove CAPI application from channel
+ * helper function to keep indentation levels down and stay in 80 columns
+ */
+
+static inline void remove_appl_from_channel(struct bc_state *bcs,
+					    struct gigaset_capi_appl *ap)
+{
+	struct cardstate *cs = bcs->cs;
+	struct gigaset_capi_appl *bcap;
+	unsigned long flags;
+	int prevconnstate;
+
+	spin_lock_irqsave(&bcs->aplock, flags);
+	bcap = bcs->ap;
+	if (bcap == NULL) {
+		spin_unlock_irqrestore(&bcs->aplock, flags);
+		return;
+	}
+
+	/* check first application on channel */
+	if (bcap == ap) {
+		bcs->ap = ap->bcnext;
+		if (bcs->ap != NULL) {
+			spin_unlock_irqrestore(&bcs->aplock, flags);
+			return;
+		}
+
+		/* none left, clear channel state */
+		prevconnstate = bcs->apconnstate;
+		bcs->apconnstate = APCONN_NONE;
+		spin_unlock_irqrestore(&bcs->aplock, flags);
+
+		if (prevconnstate == APCONN_ACTIVE) {
+			dev_notice(cs->dev, "%s: hanging up channel %u\n",
+				   __func__, bcs->channel);
+			gigaset_add_event(cs, &bcs->at_state,
+					  EV_HUP, NULL, 0, NULL);
+			gigaset_schedule_event(cs);
+		}
+		return;
+	}
+
+	/* check remaining list */
+	do {
+		if (bcap->bcnext == ap) {
+			bcap->bcnext = bcap->bcnext->bcnext;
+			return;
+		}
+		bcap = bcap->bcnext;
+	} while (bcap != NULL);
+	spin_unlock_irqrestore(&bcs->aplock, flags);
 }
 
 /*
@@ -975,19 +1060,19 @@ static void gigaset_release_appl(struct capi_ctr *ctr, u16 appl)
 		= container_of(ctr, struct gigaset_capi_ctr, ctr);
 	struct cardstate *cs = iif->ctr.driverdata;
 	struct gigaset_capi_appl *ap, *tmp;
+	unsigned ch;
 
 	list_for_each_entry_safe(ap, tmp, &iif->appls, ctrlist)
 		if (ap->id == appl) {
-			if (ap->connected != APCONN_NONE) {
-				dev_err(cs->dev,
-					"%s: application %u still connected\n",
-					__func__, ap->id);
-				/* ToDo: clear active connection */
-			}
+			/* remove from any channels */
+			for (ch = 0; ch < cs->channels; ch++)
+				remove_appl_from_channel(&cs->bcs[ch], ap);
+
+			/* remove from registration list */
 			list_del(&ap->ctrlist);
 			kfree(ap);
+			dev_info(cs->dev, "application %u released\n", appl);
 		}
-
 }
 
 /*
@@ -1166,6 +1251,7 @@ static void do_connect_req(struct gigaset_capi_ctr *iif,
 	char **commands;
 	char *s;
 	u8 *pp;
+	unsigned long flags;
 	int i, l, lbc, lhlc;
 	u16 info;
 
@@ -1181,8 +1267,15 @@ static void do_connect_req(struct gigaset_capi_ctr *iif,
 		send_conf(iif, ap, skb, CapiNoPlciAvailable);
 		return;
 	}
+	spin_lock_irqsave(&bcs->aplock, flags);
+	if (bcs->ap != NULL || bcs->apconnstate != APCONN_NONE)
+		dev_warn(cs->dev, "%s: channel not properly cleared (%p/%d)\n",
+			 __func__, bcs->ap, bcs->apconnstate);
 	ap->bcnext = NULL;
 	bcs->ap = ap;
+	bcs->apconnstate = APCONN_SETUP;
+	spin_unlock_irqrestore(&bcs->aplock, flags);
+
 	bcs->rx_bufsize = ap->rp.datablklen;
 	dev_kfree_skb(bcs->rx_skb);
 	gigaset_new_rx_skb(bcs);
@@ -1419,7 +1512,6 @@ static void do_connect_req(struct gigaset_capi_ctr *iif,
 		goto error;
 	}
 	gigaset_schedule_event(cs);
-	ap->connected = APCONN_SETUP;
 	send_conf(iif, ap, skb, CapiSuccess);
 	return;
 
@@ -1447,6 +1539,7 @@ static void do_connect_resp(struct gigaset_capi_ctr *iif,
 	_cmsg *cmsg = &iif->acmsg;
 	struct bc_state *bcs;
 	struct gigaset_capi_appl *oap;
+	unsigned long flags;
 	int channel;
 
 	/* decode message */
@@ -1466,12 +1559,21 @@ static void do_connect_resp(struct gigaset_capi_ctr *iif,
 	switch (cmsg->Reject) {
 	case 0:		/* Accept */
 		/* drop all competing applications, keep only this one */
-		for (oap = bcs->ap; oap != NULL; oap = oap->bcnext)
-			if (oap != ap)
+		spin_lock_irqsave(&bcs->aplock, flags);
+		while (bcs->ap != NULL) {
+			oap = bcs->ap;
+			bcs->ap = oap->bcnext;
+			if (oap != ap) {
+				spin_unlock_irqrestore(&bcs->aplock, flags);
 				send_disconnect_ind(bcs, oap,
 					CapiCallGivenToOtherApplication);
+				spin_lock_irqsave(&bcs->aplock, flags);
+			}
+		}
 		ap->bcnext = NULL;
 		bcs->ap = ap;
+		spin_unlock_irqrestore(&bcs->aplock, flags);
+
 		bcs->rx_bufsize = ap->rp.datablklen;
 		dev_kfree_skb(bcs->rx_skb);
 		gigaset_new_rx_skb(bcs);
@@ -1542,31 +1644,45 @@ static void do_connect_resp(struct gigaset_capi_ctr *iif,
 		send_disconnect_ind(bcs, ap, 0);
 
 		/* remove it from the list of listening apps */
+		spin_lock_irqsave(&bcs->aplock, flags);
 		if (bcs->ap == ap) {
 			bcs->ap = ap->bcnext;
-			if (bcs->ap == NULL)
+			if (bcs->ap == NULL) {
 				/* last one: stop ev-layer hupD notifications */
+				bcs->apconnstate = APCONN_NONE;
 				bcs->chstate &= ~CHS_NOTIFY_LL;
+			}
+			spin_unlock_irqrestore(&bcs->aplock, flags);
 			return;
 		}
 		for (oap = bcs->ap; oap != NULL; oap = oap->bcnext) {
 			if (oap->bcnext == ap) {
 				oap->bcnext = oap->bcnext->bcnext;
+				spin_unlock_irqrestore(&bcs->aplock, flags);
 				return;
 			}
 		}
+		spin_unlock_irqrestore(&bcs->aplock, flags);
 		dev_err(cs->dev, "%s: application %u not found\n",
 			__func__, ap->id);
 		return;
 
 	default:		/* Reject */
 		/* drop all competing applications, keep only this one */
-		for (oap = bcs->ap; oap != NULL; oap = oap->bcnext)
-			if (oap != ap)
+		spin_lock_irqsave(&bcs->aplock, flags);
+		while (bcs->ap != NULL) {
+			oap = bcs->ap;
+			bcs->ap = oap->bcnext;
+			if (oap != ap) {
+				spin_unlock_irqrestore(&bcs->aplock, flags);
 				send_disconnect_ind(bcs, oap,
 					CapiCallGivenToOtherApplication);
+				spin_lock_irqsave(&bcs->aplock, flags);
+			}
+		}
 		ap->bcnext = NULL;
 		bcs->ap = ap;
+		spin_unlock_irqrestore(&bcs->aplock, flags);
 
 		/* reject call - will trigger DISCONNECT_IND for this app */
 		dev_info(cs->dev, "%s: Reject=%x\n",
@@ -1589,6 +1705,7 @@ static void do_connect_b3_req(struct gigaset_capi_ctr *iif,
 {
 	struct cardstate *cs = iif->ctr.driverdata;
 	_cmsg *cmsg = &iif->acmsg;
+	struct bc_state *bcs;
 	int channel;
 
 	/* decode message */
@@ -1603,9 +1720,10 @@ static void do_connect_b3_req(struct gigaset_capi_ctr *iif,
 		send_conf(iif, ap, skb, CapiIllContrPlciNcci);
 		return;
 	}
+	bcs = &cs->bcs[channel-1];
 
 	/* mark logical connection active */
-	ap->connected = APCONN_ACTIVE;
+	bcs->apconnstate = APCONN_ACTIVE;
 
 	/* build NCCI: always 1 (one B3 connection only) */
 	cmsg->adr.adrNCCI |= 1 << 16;
@@ -1651,7 +1769,7 @@ static void do_connect_b3_resp(struct gigaset_capi_ctr *iif,
 
 	if (cmsg->Reject) {
 		/* Reject: clear B3 connect received flag */
-		ap->connected = APCONN_SETUP;
+		bcs->apconnstate = APCONN_SETUP;
 
 		/* trigger hangup, causing eventual DISCONNECT_IND */
 		if (!gigaset_add_event(cs, &bcs->at_state,
@@ -1723,11 +1841,11 @@ static void do_disconnect_req(struct gigaset_capi_ctr *iif,
 	}
 
 	/* skip if DISCONNECT_IND already sent */
-	if (!ap->connected)
+	if (!bcs->apconnstate)
 		return;
 
 	/* check for active logical connection */
-	if (ap->connected >= APCONN_ACTIVE) {
+	if (bcs->apconnstate >= APCONN_ACTIVE) {
 		/*
 		 * emit DISCONNECT_B3_IND with cause 0x3301
 		 * use separate cmsg structure, as the content of iif->acmsg
@@ -1776,6 +1894,7 @@ static void do_disconnect_b3_req(struct gigaset_capi_ctr *iif,
 {
 	struct cardstate *cs = iif->ctr.driverdata;
 	_cmsg *cmsg = &iif->acmsg;
+	struct bc_state *bcs;
 	int channel;
 
 	/* decode message */
@@ -1791,17 +1910,17 @@ static void do_disconnect_b3_req(struct gigaset_capi_ctr *iif,
 		send_conf(iif, ap, skb, CapiIllContrPlciNcci);
 		return;
 	}
+	bcs = &cs->bcs[channel-1];
 
 	/* reject if logical connection not active */
-	if (ap->connected < APCONN_ACTIVE) {
+	if (bcs->apconnstate < APCONN_ACTIVE) {
 		send_conf(iif, ap, skb,
 			  CapiMessageNotSupportedInCurrentState);
 		return;
 	}
 
 	/* trigger hangup, causing eventual DISCONNECT_B3_IND */
-	if (!gigaset_add_event(cs, &cs->bcs[channel-1].at_state,
-			       EV_HUP, NULL, 0, NULL)) {
+	if (!gigaset_add_event(cs, &bcs->at_state, EV_HUP, NULL, 0, NULL)) {
 		send_conf(iif, ap, skb, CAPI_MSGOSRESOURCEERR);
 		return;
 	}
@@ -1822,6 +1941,7 @@ static void do_data_b3_req(struct gigaset_capi_ctr *iif,
 			   struct sk_buff *skb)
 {
 	struct cardstate *cs = iif->ctr.driverdata;
+	struct bc_state *bcs;
 	int channel = CAPIMSG_PLCI_PART(skb->data);
 	u16 ncci = CAPIMSG_NCCI_PART(skb->data);
 	u16 msglen = CAPIMSG_LEN(skb->data);
@@ -1844,6 +1964,7 @@ static void do_data_b3_req(struct gigaset_capi_ctr *iif,
 		send_conf(iif, ap, skb, CapiIllContrPlciNcci);
 		return;
 	}
+	bcs = &cs->bcs[channel-1];
 	if (msglen != CAPI_DATA_B3_REQ_LEN && msglen != CAPI_DATA_B3_REQ_LEN64)
 		dev_notice(cs->dev, "%s: unexpected length %d\n",
 			   "DATA_B3_REQ", msglen);
@@ -1863,7 +1984,7 @@ static void do_data_b3_req(struct gigaset_capi_ctr *iif,
 	}
 
 	/* reject if logical connection not active */
-	if (ap->connected < APCONN_ACTIVE) {
+	if (bcs->apconnstate < APCONN_ACTIVE) {
 		send_conf(iif, ap, skb, CapiMessageNotSupportedInCurrentState);
 		return;
 	}
@@ -1874,7 +1995,7 @@ static void do_data_b3_req(struct gigaset_capi_ctr *iif,
 	skb_pull(skb, msglen);
 
 	/* pass to device-specific module */
-	if (cs->ops->send_skb(&cs->bcs[channel-1], skb) < 0) {
+	if (cs->ops->send_skb(bcs, skb) < 0) {
 		send_conf(iif, ap, skb, CAPI_MSGOSRESOURCEERR);
 		return;
 	}
diff --git a/drivers/isdn/gigaset/common.c b/drivers/isdn/gigaset/common.c
index 9778fabbc488..5d4befb81057 100644
--- a/drivers/isdn/gigaset/common.c
+++ b/drivers/isdn/gigaset/common.c
@@ -649,6 +649,10 @@ static struct bc_state *gigaset_initbcs(struct bc_state *bcs,
 	for (i = 0; i < AT_NUM; ++i)
 		bcs->commands[i] = NULL;
 
+	spin_lock_init(&bcs->aplock);
+	bcs->ap = NULL;
+	bcs->apconnstate = 0;
+
 	gig_dbg(DEBUG_INIT, "  setting up bcs[%d]->hw", channel);
 	if (cs->ops->initbcshw(bcs))
 		return bcs;
diff --git a/drivers/isdn/gigaset/gigaset.h b/drivers/isdn/gigaset/gigaset.h
index c4e6c26897ea..8738b0821fc9 100644
--- a/drivers/isdn/gigaset/gigaset.h
+++ b/drivers/isdn/gigaset/gigaset.h
@@ -403,7 +403,9 @@ struct bc_state {
 		struct bas_bc_state *bas;	/* usb hardware driver (base) */
 	} hw;
 
-	void *ap;			/* LL application structure */
+	void *ap;			/* associated LL application */
+	int apconnstate;		/* LL application connection state */
+	spinlock_t aplock;
 };
 
 struct cardstate {