ISDN: Pass around struct isdn_slot directly

The common way in the kernel is to pass around the struct (e.g.
struct net_device), and leave the user the possibility to add
its private data using ::priv, so do it the same way when accessing
an ISDN channel.

10 files changed, 190 insertions, 238 deletions

diff --git a/drivers/isdn/i4l/isdn_common.c b/drivers/isdn/i4l/isdn_common.c
index 941d75df098a..3a2f833798f0 100644
--- a/drivers/isdn/i4l/isdn_common.c
+++ b/drivers/isdn/i4l/isdn_common.c
@@ -26,7 +26,6 @@
 #include "isdn_audio.h"
 #endif
 #include <linux/isdn_divertif.h>
-#include "isdn_v110.h"
 #include <linux/devfs_fs_kernel.h>
 
 MODULE_DESCRIPTION("ISDN4Linux: link layer");
@@ -57,22 +56,6 @@ static char *slot_st_str[] = {
 	"ST_SLOT_WAIT_DHUP",
 };
 
-struct isdn_slot {
-	int               di;                  /* driver index               */
-	struct isdn_driver *drv;               /* driver                     */
-	int               ch;                  /* channel index (per driver) */
-	int               usage;               /* how is it used             */
-	char              num[ISDN_MSNLEN];    /* the current phone number   */
-	unsigned long     ibytes;              /* Statistics incoming bytes  */
-	unsigned long     obytes;              /* Statistics outgoing bytes  */
-	struct isdn_v110  iv110;               /* For V.110                  */
-	int               m_idx;               /* Index for mdm....          */
-	void             *priv;                /* pointer to isdn_net_dev    */
-	int             (*event_cb)(int sl, int pr, void *arg);
-	struct fsm_inst   fi;
-};
-
-
 static char *ev_str[] = {
 	"EV_DRV_REGISTER",
 	"EV_STAT_RUN",
@@ -117,10 +100,8 @@ static int  isdn_v110_data_req(struct isdn_slot *slot, struct sk_buff *skb);
 static inline int
 do_event_cb(struct isdn_slot *slot, int pr, void *arg)
 {
-	int sl = slot - slots;
-
 	if (slot->event_cb)
-		return slot->event_cb(sl, pr, arg);
+		return slot->event_cb(slot, pr, arg);
 
 	return -ENXIO;
 }
@@ -304,7 +285,6 @@ slot_icall(struct fsm_inst *fi, int pr, void *arg)
 {
 	struct isdn_slot *slot = fi->userdata;
 	isdn_ctrl *ctrl = arg;
-	int sl = slot - slots;
 	int retval;
 
 	fsm_change_state(fi, ST_SLOT_IN);
@@ -314,15 +294,13 @@ slot_icall(struct fsm_inst *fi, int pr, void *arg)
 	
 	strcpy(slot->num, ctrl->parm.setup.phone);
 	/* Try to find a network-interface which will accept incoming call */
-	retval = isdn_net_find_icall(ctrl->driver, ctrl->arg, sl, 
-				     &ctrl->parm.setup);
+	retval = isdn_net_find_icall(slot, &ctrl->parm.setup);
 
 	/* already taken by net now? */
 	if (fi->state != ST_SLOT_IN)
 		goto out;
 
-	retval = isdn_tty_find_icall(ctrl->driver, ctrl->arg, sl, 
-				     &ctrl->parm.setup);
+	retval = isdn_tty_find_icall(slot, &ctrl->parm.setup);
  out:
 	return 0;
 }
@@ -342,12 +320,11 @@ static int
 slot_unbind(struct fsm_inst *fi, int pr, void *arg)
 {
 	struct isdn_slot *slot = fi->userdata;
-	int sl = slot - slots;
 	isdn_ctrl cmd;
 
 	strcpy(slot->num, "???");
 	cmd.parm.num[0] = '\0';
-	isdn_slot_command(sl, ISDN_CMD_SETEAZ, &cmd);
+	isdn_slot_command(slot, ISDN_CMD_SETEAZ, &cmd);
 	slot->ibytes = 0;
 	slot->obytes = 0;
 	slot->usage = ISDN_USAGE_NONE;
@@ -1990,7 +1967,7 @@ isdn_map_eaz2msn(char *msn, int di)
  * Find an unused ISDN-channel, whose feature-flags match the
  * given L2- and L3-protocols.
  */
-int
+struct isdn_slot *
 isdn_get_free_slot(int usage, int l2_proto, int l3_proto,
 		   int pre_dev, int pre_chan, char *msn)
 {
@@ -2029,32 +2006,28 @@ isdn_get_free_slot(int usage, int l2_proto, int l3_proto,
 			slot->usage = usage;
 			isdn_info_update();
 			fsm_event(&slot->fi, EV_SLOT_BIND, NULL);
-			return i;
+			return slot;
 		}
 	}
 	restore_flags(flags);
-	return -1;
+	return NULL;
 }
 
 /*
  * Set state of ISDN-channel to 'unused'
  */
 void
-isdn_slot_free(int sl)
+isdn_slot_free(struct isdn_slot *slot)
 {
-	fsm_event(&slots[sl].fi, EV_SLOT_UNBIND, NULL);
+	fsm_event(&slot->fi, EV_SLOT_UNBIND, NULL);
 }
 
 /*
  * Return: length of data on success, -ERRcode on failure.
  */
 int
-isdn_slot_write(int sl, struct sk_buff *skb)
+isdn_slot_write(struct isdn_slot *slot, struct sk_buff *skb)
 {
-	struct isdn_slot *slot = &slots[sl];
-
-	BUG_ON(sl < 0);
-
 	return fsm_event(&slot->fi, EV_DATA_REQ, skb);
 }
 
@@ -2157,38 +2130,26 @@ EXPORT_SYMBOL(isdn_ppp_unregister_compressor);
 #endif
 
 int
-isdn_slot_maxbufsize(int sl)
+isdn_slot_maxbufsize(struct isdn_slot *slot)
 {
-	BUG_ON(sl < 0);
-
-	return slots[sl].drv->maxbufsize;
+	return slot->drv->maxbufsize;
 }
 
 int
-isdn_slot_hdrlen(int sl)
+isdn_slot_hdrlen(struct isdn_slot *slot)
 {
-	struct isdn_slot *slot = &slots[sl];
-	
-	BUG_ON(sl < 0);
-	
 	return slot->drv->interface->hl_hdrlen;
 }
 
 char *
-isdn_slot_map_eaz2msn(int sl, char *msn)
+isdn_slot_map_eaz2msn(struct isdn_slot *slot, char *msn)
 {
-	struct isdn_slot *slot = &slots[sl];
-	
-	BUG_ON(sl < 0);
-	
 	return isdn_map_eaz2msn(msn, slot->di);
 }
 
 int
-isdn_slot_command(int sl, int cmd, isdn_ctrl *ctrl)
+isdn_slot_command(struct isdn_slot *slot, int cmd, isdn_ctrl *ctrl)
 {
-	struct isdn_slot *slot = &slots[sl];
-
 	ctrl->command = cmd;
 	ctrl->driver = slot->di;
 
@@ -2230,14 +2191,11 @@ isdn_slot_command(int sl, int cmd, isdn_ctrl *ctrl)
 }
 
 int
-isdn_slot_dial(int sl, struct dial_info *dial)
+isdn_slot_dial(struct isdn_slot *slot, struct dial_info *dial)
 {
-	struct isdn_slot *slot = &slots[sl];
 	isdn_ctrl cmd;
 	int retval;
-	char *msn = isdn_slot_map_eaz2msn(sl, dial->msn);
-
-	BUG_ON(sl < 0);
+	char *msn = isdn_slot_map_eaz2msn(slot, dial->msn);
 
 	/* check for DOV */
 	if (dial->si1 == 7 && tolower(dial->phone[0]) == 'v') { /* DOV call */
@@ -2249,21 +2207,21 @@ isdn_slot_dial(int sl, struct dial_info *dial)
 	slot->usage |= ISDN_USAGE_OUTGOING;
 	isdn_info_update();
 
-	retval = isdn_slot_command(sl, ISDN_CMD_CLREAZ, &cmd);
+	retval = isdn_slot_command(slot, ISDN_CMD_CLREAZ, &cmd);
 	if (retval)
 		return retval;
 
 	strcpy(cmd.parm.num, msn);
-	retval = isdn_slot_command(sl, ISDN_CMD_SETEAZ, &cmd);
+	retval = isdn_slot_command(slot, ISDN_CMD_SETEAZ, &cmd);
 
 	cmd.arg = dial->l2_proto << 8;
 	cmd.parm.fax = dial->fax;
-	retval = isdn_slot_command(sl, ISDN_CMD_SETL2, &cmd);
+	retval = isdn_slot_command(slot, ISDN_CMD_SETL2, &cmd);
 	if (retval)
 		return retval;
 
 	cmd.arg = dial->l3_proto << 8;
-	retval = isdn_slot_command(sl, ISDN_CMD_SETL3, &cmd);
+	retval = isdn_slot_command(slot, ISDN_CMD_SETL3, &cmd);
 	if (retval)
 		return retval;
 
@@ -2272,12 +2230,12 @@ isdn_slot_dial(int sl, struct dial_info *dial)
 	strcpy(cmd.parm.setup.eazmsn, msn);
 	strcpy(cmd.parm.setup.phone, dial->phone);
 
-	printk(KERN_INFO "ISDN: slot %d: Dialing %s -> %s (SI %d/%d) (B %d/%d)\n",
-	       sl, cmd.parm.setup.eazmsn, cmd.parm.setup.phone,
+	printk(KERN_INFO "ISDN: Dialing %s -> %s (SI %d/%d) (B %d/%d)\n",
+	       cmd.parm.setup.eazmsn, cmd.parm.setup.phone,
 	       cmd.parm.setup.si1, cmd.parm.setup.si2,
 	       dial->l2_proto, dial->l3_proto);
 
-	return isdn_slot_command(sl, ISDN_CMD_DIAL, &cmd);
+	return isdn_slot_command(slot, ISDN_CMD_DIAL, &cmd);
 }
 
 int
@@ -2297,39 +2255,15 @@ isdn_slot_m_idx(int sl)
 }
 
 void
-isdn_slot_set_m_idx(int sl, int midx)
+isdn_slot_set_m_idx(struct isdn_slot *slot, int midx)
 {
-	BUG_ON(sl < 0);
-
-	slots[sl].m_idx = midx;
+	slot->m_idx = midx;
 }
 
 char *
-isdn_slot_num(int sl)
-{
-	BUG_ON(sl < 0);
-
-	return slots[sl].num;
-}
-
-void
-isdn_slot_set_priv(int sl, int usage, void *priv, 
-		   int (*event_cb)(int sl, int pr, void *arg))
-{
-	BUG_ON(sl < 0);
-
-	slots[sl].usage &= ISDN_USAGE_EXCLUSIVE;
-	slots[sl].usage |= usage;
-	slots[sl].priv = priv;
-	slots[sl].event_cb = event_cb;
-}
-
-void *
-isdn_slot_priv(int sl)
+isdn_slot_num(struct isdn_slot *slot)
 {
-	BUG_ON(sl < 0);
-
-	return slots[sl].priv;
+	return slot->num;
 }
 
 int
@@ -2548,35 +2482,29 @@ isdn_v110_add_features(struct isdn_driver *drv)
 static void
 __isdn_v110_open(struct isdn_slot *slot)
 {
-	int sl = slot - slots;
-
 	if (!slot->iv110.v110emu)
 		return;
 
-	isdn_v110_open(sl, &slot->iv110);
+	isdn_v110_open(slot, &slot->iv110);
 }
 
 static void
 __isdn_v110_close(struct isdn_slot *slot)
 {
-	int sl = slot - slots;
-
 	if (!slot->iv110.v110emu)
 		return;
 
-	isdn_v110_close(sl, &slot->iv110);
+	isdn_v110_close(slot, &slot->iv110);
 }
 
 static void
 __isdn_v110_bsent(struct isdn_slot *slot, int pr, isdn_ctrl *c)
 {
-	int sl = slot - slots;
-
 	if (!slot->iv110.v110emu) {
 		do_event_cb(slot, pr, c);
 		return;
 	}
-	isdn_v110_bsent(sl, &slot->iv110);
+	isdn_v110_bsent(slot, &slot->iv110);
 }
 
 /*
@@ -2615,8 +2543,6 @@ isdn_v110_setl2(struct isdn_slot *slot, isdn_ctrl *cmd)
 static int
 isdn_v110_data_ind(struct isdn_slot *slot, struct sk_buff *skb)
 {
-	int sl = slot - slots;
-
 	if (!slot->iv110.v110emu)
 		goto recv;
 		
@@ -2626,7 +2552,7 @@ isdn_v110_data_ind(struct isdn_slot *slot, struct sk_buff *skb)
 
 recv:
 	if (slot->event_cb)
-		slot->event_cb(sl, EV_DATA_IND, skb);
+		slot->event_cb(slot, EV_DATA_IND, skb);
 	return 0;
 }
 
diff --git a/drivers/isdn/i4l/isdn_common.h b/drivers/isdn/i4l/isdn_common.h
index df087a2316b8..294c17956f39 100644
--- a/drivers/isdn/i4l/isdn_common.h
+++ b/drivers/isdn/i4l/isdn_common.h
@@ -10,6 +10,7 @@
  */
 
 #include <linux/isdn.h>
+#include "isdn_v110.h"
 
 #undef  ISDN_DEBUG_MODEM_OPEN
 #undef  ISDN_DEBUG_MODEM_IOCTL
@@ -68,6 +69,21 @@ extern void isdn_dumppkt(char *, u_char *, int, int);
 static inline void isdn_dumppkt(char *s, u_char *d, int l, int m) { }
 #endif
 
+struct isdn_slot {
+	int               di;                  /* driver index               */
+	struct isdn_driver *drv;               /* driver                     */
+	int               ch;                  /* channel index (per driver) */
+	int               usage;               /* how is it used             */
+	char              num[ISDN_MSNLEN];    /* the current phone number   */
+	unsigned long     ibytes;              /* Statistics incoming bytes  */
+	unsigned long     obytes;              /* Statistics outgoing bytes  */
+	struct isdn_v110  iv110;               /* For V.110                  */
+	int               m_idx;               /* Index for mdm....          */
+	void             *priv;                /* pointer to isdn_net_dev    */
+	int             (*event_cb)(struct isdn_slot *, int pr, void *arg);
+	struct fsm_inst   fi;
+};
+
 struct dial_info {
 	int            l2_proto;
 	int            l3_proto;
@@ -78,22 +94,19 @@ struct dial_info {
 	unsigned char *phone;
 };
 
-extern int   isdn_get_free_slot(int, int, int, int, int, char *);
-extern void  isdn_slot_free(int slot);
-extern int   isdn_slot_command(int slot, int cmd, isdn_ctrl *);
-extern int   isdn_slot_dial(int slot, struct dial_info *dial);
-extern char *isdn_slot_map_eaz2msn(int slot, char *msn);
-extern int   isdn_slot_write(int slot, struct sk_buff *);
-extern int   isdn_slot_hdrlen(int slot);
-extern int   isdn_slot_maxbufsize(int slot);
-extern int   isdn_slot_usage(int slot);
-extern char *isdn_slot_num(int slot);
-extern int   isdn_slot_m_idx(int slot);
-extern void  isdn_slot_set_m_idx(int slot, int midx);
-extern void  isdn_slot_set_priv(int sl, int usage, void *priv, 
-				int (*event_cb)(int sl, int pr, void *arg));
-extern void *isdn_slot_priv(int sl);
-extern int   isdn_hard_header_len(void);
+struct isdn_slot *isdn_get_free_slot(int, int, int, int, int, char *);
+void  isdn_slot_free(struct isdn_slot *);
+int   isdn_slot_command(struct isdn_slot *, int cmd, isdn_ctrl *);
+int   isdn_slot_dial(struct isdn_slot *, struct dial_info *dial);
+char *isdn_slot_map_eaz2msn(struct isdn_slot *, char *msn);
+int   isdn_slot_write(struct isdn_slot *, struct sk_buff *);
+int   isdn_slot_hdrlen(struct isdn_slot *);
+int   isdn_slot_maxbufsize(struct isdn_slot *);
+char *isdn_slot_num(struct isdn_slot *);
+void  isdn_slot_set_m_idx(struct isdn_slot *, int midx);
+int   isdn_hard_header_len(void);
+int   isdn_slot_m_idx(int sl);
+int   isdn_slot_usage(int sl);
 
 int   isdn_drv_lookup(char *drvid);
 char *isdn_drv_drvid(int di);
diff --git a/drivers/isdn/i4l/isdn_net_lib.c b/drivers/isdn/i4l/isdn_net_lib.c
index 22621984d4eb..78e3874c46a2 100644
--- a/drivers/isdn/i4l/isdn_net_lib.c
+++ b/drivers/isdn/i4l/isdn_net_lib.c
@@ -294,21 +294,21 @@ isdn_net_bind(isdn_net_dev *idev, isdn_net_ioctl_cfg *cfg)
 			goto out;
 		}
 	}
-	if (cfg->exclusive == (idev->exclusive >= 0) &&
+	if (cfg->exclusive == !!idev->exclusive &&
 	    drvidx == idev->pre_device && chidx == idev->pre_channel) {
 		/* no change */
 		retval = 0;
 		goto out;
 	}
-	if (idev->exclusive >= 0) {
+	if (idev->exclusive) {
 		isdn_slot_free(idev->exclusive);
-		idev->exclusive = -1;
+		idev->exclusive = NULL;
 	}
 	if (cfg->exclusive) {
 		/* If binding is exclusive, try to grab the channel */
 		idev->exclusive = isdn_get_free_slot(ISDN_USAGE_NET | ISDN_USAGE_EXCLUSIVE, 
 						     mlp->l2_proto, mlp->l3_proto, drvidx, chidx, cfg->eaz);
-		if (idev->exclusive < 0) {
+		if (!idev->exclusive) {
 			/* Grab failed, because desired channel is in use */
 			retval = -EBUSY;
 			goto out;
@@ -368,10 +368,10 @@ isdn_net_addif(char *name, isdn_net_local *mlp)
 	tasklet_init(&idev->tlet, isdn_net_tasklet, (unsigned long) idev);
 	skb_queue_head_init(&idev->super_tx_queue);
 
-	idev->isdn_slot = -1;
+	idev->isdn_slot = NULL;
 	idev->pre_device = -1;
 	idev->pre_channel = -1;
-	idev->exclusive = -1;
+	idev->exclusive = NULL;
 
 	idev->pppbind = -1;
 
@@ -643,7 +643,7 @@ isdn_net_getcfg(isdn_net_ioctl_cfg *cfg)
 	mlp = idev->mlp;
 
 	strcpy(cfg->eaz, mlp->msn);
-	cfg->exclusive = idev->exclusive >= 0;
+	cfg->exclusive = !!idev->exclusive;
 	if (idev->pre_device >= 0) {
 		sprintf(cfg->drvid, "%s,%d", isdn_drv_drvid(idev->pre_device),
 			idev->pre_channel);
@@ -853,7 +853,7 @@ static int
 isdn_net_getpeer(isdn_net_ioctl_phone *phone, isdn_net_ioctl_phone *peer)
 {
 	isdn_net_dev *idev = isdn_net_findif(phone->name);
-	int idx;
+	struct isdn_slot *slot;
 
 	if (!idev)
 		return -ENODEV;
@@ -863,15 +863,15 @@ isdn_net_getpeer(isdn_net_ioctl_phone *phone, isdn_net_ioctl_phone *peer)
          * in (partially) wrong number copied to user. This race
 	 * currently ignored.
 	 */
-	idx = idev->isdn_slot;
-	if (idx < 0)
+	slot = idev->isdn_slot;
+	if (slot < 0)
 		return -ENOTCONN;
 	/* for pre-bound channels, we need this extra check */
-	if (strncmp(isdn_slot_num(idx), "???", 3) == 0 )
+	if (strncmp(isdn_slot_num(slot), "???", 3) == 0 )
 		return -ENOTCONN;
 
-	strncpy(phone->phone, isdn_slot_num(idx), ISDN_MSNLEN);
-	phone->outgoing = USG_OUTGOING(isdn_slot_usage(idx));
+	strncpy(phone->phone, isdn_slot_num(slot), ISDN_MSNLEN);
+	phone->outgoing = USG_OUTGOING(slot->usage);
 
 	if (copy_to_user(peer, phone, sizeof(*peer)))
 		return -EFAULT;
@@ -1202,14 +1202,15 @@ isdn_net_unbind_channel(isdn_net_dev *idev)
 	if (mlp->ops->unbind)
 		mlp->ops->unbind(idev);
 
-	isdn_slot_set_priv(idev->isdn_slot, 0, NULL, NULL);
+	idev->isdn_slot->priv = NULL;
+	idev->isdn_slot->event_cb = NULL;
 
 	skb_queue_purge(&idev->super_tx_queue);
 
 	if (idev->isdn_slot != idev->exclusive)
 		isdn_slot_free(idev->isdn_slot);
 
-	idev->isdn_slot = -1;
+	idev->isdn_slot = NULL;
 
 	if (idev->fi.state != ST_NULL) {
 		lp_put(mlp);
@@ -1217,27 +1218,29 @@ isdn_net_unbind_channel(isdn_net_dev *idev)
 	}
 }
 
-static int isdn_net_event_callback(int sl, int pr, void *arg);
+static int isdn_net_event_callback(struct isdn_slot *slot, int pr, void *arg);
 
 /*
  * Assign an ISDN-channel to a net-interface
  */
 static int
-isdn_net_bind_channel(isdn_net_dev *idev, int slot)
+isdn_net_bind_channel(isdn_net_dev *idev, struct isdn_slot *slot)
 {
 	isdn_net_local *mlp = idev->mlp;
 	int retval = 0;
 
-	idev->isdn_slot = slot;
-	isdn_slot_set_priv(idev->isdn_slot, ISDN_USAGE_NET, idev,
-			   isdn_net_event_callback);
-
 	if (mlp->ops->bind)
 		retval = mlp->ops->bind(idev);
 
 	if (retval < 0)
-		isdn_net_unbind_channel(idev);
+		goto out;
 
+	idev->isdn_slot = slot;
+	slot->priv = idev;
+	slot->event_cb = isdn_net_event_callback;
+	slot->usage |= ISDN_USAGE_NET;
+
+ out:
 	return retval;
 }
 
@@ -1368,7 +1371,7 @@ accept_icall(struct fsm_inst *fi, int pr, void *arg)
 	isdn_net_dev *idev = fi->userdata;
 	isdn_net_local *mlp = idev->mlp;
 	isdn_ctrl cmd;
-	int slot = (int) arg;
+	struct isdn_slot *slot = arg;
 
 	isdn_net_bind_channel(idev, slot);
 	
@@ -1407,8 +1410,8 @@ do_callback(struct fsm_inst *fi, int pr, void *arg)
 }
 
 static int
-isdn_net_dev_icall(isdn_net_dev *idev, int slot, int di, int ch, int si1,
-		   char *eaz, char *nr)
+isdn_net_dev_icall(isdn_net_dev *idev, struct isdn_slot *slot,
+		   int si1, char *eaz, char *nr)
 {
 	isdn_net_local *mlp = idev->mlp;
 	struct isdn_net_phone *ph;
@@ -1438,11 +1441,11 @@ isdn_net_dev_icall(isdn_net_dev *idev, int slot, int di, int ch, int si1,
 	}
 
 	dbg_net_icall("%s: pdev=%d di=%d pch=%d ch = %d\n", idev->name,
-		      idev->pre_device, di, idev->pre_channel, ch);
+		      idev->pre_device, slot->di, idev->pre_channel, slot->ch);
 	
 	/* check if exclusive */
-	if ((isdn_slot_usage(slot) & ISDN_USAGE_EXCLUSIVE) &&
-	    (idev->pre_channel != ch || idev->pre_device != di)) {
+	if ((slot->usage & ISDN_USAGE_EXCLUSIVE) &&
+	    (idev->pre_channel != slot->ch || idev->pre_device != slot->di)) {
 		dbg_net_icall("%s: excl check failed\n", idev->name);
 		return 0;
 	}
@@ -1476,7 +1479,7 @@ isdn_net_dev_icall(isdn_net_dev *idev, int slot, int di, int ch, int si1,
 	printk(KERN_INFO "%s: call from %s -> %s accepted\n",
 	       idev->name, nr, eaz);
 
-	if (fsm_event(&idev->fi, EV_NET_DO_ACCEPT, (void *) slot)) {
+	if (fsm_event(&idev->fi, EV_NET_DO_ACCEPT, slot)) {
 		lp_put(mlp);
 		return 0;
 	}
@@ -1500,7 +1503,7 @@ isdn_net_dev_icall(isdn_net_dev *idev, int slot, int di, int ch, int si1,
  *                   would eventually match if CID was longer.
  */
 int
-isdn_net_find_icall(int di, int ch, int sl, setup_parm *setup)
+isdn_net_find_icall(struct isdn_slot *slot, setup_parm *setup)
 {
 	isdn_net_local *lp;
 	isdn_net_dev *idev;
@@ -1540,8 +1543,8 @@ isdn_net_find_icall(int di, int ch, int sl, setup_parm *setup)
                 return 0;
         }
 
-	dbg_net_icall("n_fi: di=%d ch=%d sl=%d usg=%d\n", di, ch, sl,
-		      isdn_slot_usage(sl));
+	dbg_net_icall("n_fi: di=%d ch=%d usg=%#x\n", slot->di, slot->ch,
+		      slot->usage);
 
 	retval = 0;
 	spin_lock_irqsave(&running_devs_lock, flags);
@@ -1550,7 +1553,7 @@ isdn_net_find_icall(int di, int ch, int sl, setup_parm *setup)
 		spin_unlock_irqrestore(&running_devs_lock, flags);
 
 		list_for_each_entry(idev, &lp->slaves, slaves) {
-			retval = isdn_net_dev_icall(idev, sl, di, ch, si1, eaz, nr);
+			retval = isdn_net_dev_icall(idev, slot, si1, eaz, nr);
 			if (retval > 0)
 				break;
 		}
@@ -1599,7 +1602,7 @@ do_dial(struct fsm_inst *fi, int pr, void *arg)
 {
 	isdn_net_dev *idev = fi->userdata;
 	isdn_net_local *mlp = idev->mlp;
-	int slot;
+	struct isdn_slot *slot;
 
 	if (ISDN_NET_DIALMODE(*mlp) == ISDN_NET_DM_OFF)
 		return -EPERM;
@@ -1607,13 +1610,13 @@ do_dial(struct fsm_inst *fi, int pr, void *arg)
 	if (list_empty(&mlp->phone[1])) /* no number to dial ? */
 		return -EINVAL;
 
-	if (idev->exclusive >= 0)
+	if (idev->exclusive)
 		slot = idev->exclusive;
 	else
 		slot = isdn_get_free_slot(ISDN_USAGE_NET, mlp->l2_proto,
 					  mlp->l3_proto, idev->pre_device, 
 					  idev->pre_channel, mlp->msn);
-	if (slot < 0)
+	if (!slot)
 		return -EAGAIN;
 
 	if (isdn_net_bind_channel(idev, slot) < 0) {
@@ -1856,12 +1859,12 @@ isdn_net_hangup(isdn_net_dev *idev)
 
 	printk(KERN_INFO "%s: local hangup\n", idev->name);
 	// FIXME via state machine
-	if (idev->isdn_slot >= 0)
-	  isdn_slot_command(idev->isdn_slot, ISDN_CMD_HANGUP, &cmd);
+	if (idev->isdn_slot)
+		isdn_slot_command(idev->isdn_slot, ISDN_CMD_HANGUP, &cmd);
 	return 1;
 }
 
-static int isdn_net_rcv_skb(int idx, struct sk_buff *skb);
+static int isdn_net_rcv_skb(struct isdn_slot *slot, struct sk_buff *skb);
 
 /*
  * Handle status-messages from ISDN-interfacecard.
@@ -1869,16 +1872,17 @@ static int isdn_net_rcv_skb(int idx, struct sk_buff *skb);
  * isdn_status_callback, which itself is called from the low-level driver.
  */
 static int
-isdn_net_event_callback(int sl, int pr, void *arg)
+isdn_net_event_callback(struct isdn_slot *slot, int pr, void *arg)
 {
-	isdn_net_dev *idev = isdn_slot_priv(sl);
+	isdn_net_dev *idev = slot->priv;
 
-	if (!idev)
+	if (!idev) {
+		isdn_BUG();
 		return 0;
-
+	}
 	switch (pr) {
 	case EV_DATA_IND:
-		return isdn_net_rcv_skb(sl, arg);
+		return isdn_net_rcv_skb(slot, arg);
 	case EV_STAT_DCONN:
 		return fsm_event(&idev->fi, EV_NET_STAT_DCONN, arg);
 	case EV_STAT_BCONN:
@@ -2267,9 +2271,9 @@ isdn_net_write_super(isdn_net_dev *idev, struct sk_buff *skb)
  * else return 0.
  */
 static int
-isdn_net_rcv_skb(int idx, struct sk_buff *skb)
+isdn_net_rcv_skb(struct isdn_slot *slot, struct sk_buff *skb)
 {
-	isdn_net_dev *idev = isdn_slot_priv(idx);
+	isdn_net_dev *idev = slot->priv;
 	isdn_net_local *mlp;
 
 	if (!idev) {
diff --git a/drivers/isdn/i4l/isdn_net_lib.h b/drivers/isdn/i4l/isdn_net_lib.h
index cd822e827d2f..0258036dc0fb 100644
--- a/drivers/isdn/i4l/isdn_net_lib.h
+++ b/drivers/isdn/i4l/isdn_net_lib.h
@@ -50,7 +50,7 @@ void isdn_net_lib_init(void);
 void isdn_net_lib_exit(void);
 void isdn_net_hangup_all(void);
 int  isdn_net_ioctl(struct inode *, struct file *, uint, ulong);
-int  isdn_net_find_icall(int, int, int, setup_parm *);
+int  isdn_net_find_icall(struct isdn_slot *slot, setup_parm *setup);
 
 /* provided for interface types to use */
 void isdn_net_writebuf_skb(isdn_net_dev *, struct sk_buff *skb);
@@ -133,10 +133,10 @@ struct isdn_net_local_s {
 /* per ISDN channel (ISDN interface) data */
 
 struct isdn_net_dev_s {
-  int                    isdn_slot;    /* Index to isdn device/channel     */
+  struct isdn_slot      *isdn_slot;    /* Index to isdn device/channel     */
+  struct isdn_slot      *exclusive;    /* NULL if non excl                 */
   int                    pre_device;   /* Preselected isdn-device          */
   int                    pre_channel;  /* Preselected isdn-channel         */
-  int                    exclusive;    /* -1 if non excl./idx to excl chan */
 
   struct timer_list      dial_timer;   /* dial events timer                */
   struct fsm_inst        fi;           /* call control state machine       */
diff --git a/drivers/isdn/i4l/isdn_tty.c b/drivers/isdn/i4l/isdn_tty.c
index 90b7c6bf603b..3a57ba4fa2c0 100644
--- a/drivers/isdn/i4l/isdn_tty.c
+++ b/drivers/isdn/i4l/isdn_tty.c
@@ -31,20 +31,20 @@ static void isdn_tty_modem_reset_regs(modem_info *, int);
 static void isdn_tty_cmd_ATA(modem_info *);
 static void isdn_tty_flush_buffer(struct tty_struct *);
 static void isdn_tty_modem_result(int, modem_info *);
-static int isdn_tty_stat_callback(int i, isdn_ctrl *c);
-static int isdn_tty_rcv_skb(int i, struct sk_buff *skb);
+static int isdn_tty_stat_callback(struct isdn_slot *slot, isdn_ctrl *c);
+static int isdn_tty_rcv_skb(struct isdn_slot *slot, struct sk_buff *skb);
 #ifdef CONFIG_ISDN_AUDIO
 static int isdn_tty_countDLE(unsigned char *, int);
 #endif
 
 static int
-isdn_tty_event_callback(int sl, int pr, void *arg)
+isdn_tty_event_callback(struct isdn_slot *slot, int pr, void *arg)
 {
 	switch (pr) {
 	case EV_DATA_IND:
-		return isdn_tty_rcv_skb(sl, arg);
+		return isdn_tty_rcv_skb(slot, arg);
 	default:
-		return isdn_tty_stat_callback(sl, arg);
+		return isdn_tty_stat_callback(slot, arg);
 	}
 }
 
@@ -281,7 +281,7 @@ isdn_tty_readmodem(void)
 }
 
 static int
-isdn_tty_rcv_skb(int i, struct sk_buff *skb)
+isdn_tty_rcv_skb(struct isdn_slot *slot, struct sk_buff *skb)
 {
 	ulong flags;
 #ifdef CONFIG_ISDN_AUDIO
@@ -289,7 +289,7 @@ isdn_tty_rcv_skb(int i, struct sk_buff *skb)
 #endif
 	modem_info *info;
 
-	info = isdn_slot_priv(i);
+	info = slot->priv;
 #ifdef CONFIG_ISDN_AUDIO
 	ifmt = 1;
 	
@@ -728,7 +728,7 @@ isdn_tty_dial(char *n, modem_info * info, atemu * m)
 	int si = 7;
 	int l2 = m->mdmreg[REG_L2PROT];
 	ulong flags;
-	int i;
+	struct isdn_slot *slot;
 	int j;
 
 	for (j = 7; j >= 0; j--)
@@ -751,8 +751,8 @@ isdn_tty_dial(char *n, modem_info * info, atemu * m)
 	m->mdmreg[REG_SI1I] = si2bit[si];
 	save_flags(flags);
 	cli();
-	i = isdn_get_free_slot(usg, l2, m->mdmreg[REG_L3PROT], -1, -1, m->msn);
-	if (i < 0) {
+	slot = isdn_get_free_slot(usg, l2, m->mdmreg[REG_L3PROT], -1, -1, m->msn);
+	if (!slot) {
 		restore_flags(flags);
 		isdn_tty_modem_result(RESULT_NO_DIALTONE, info);
 	} else {
@@ -765,9 +765,11 @@ isdn_tty_dial(char *n, modem_info * info, atemu * m)
 			.phone    = n,
 		};
 
-		info->isdn_slot = i;
-		isdn_slot_set_m_idx(i, info->line);
-		isdn_slot_set_priv(i, ISDN_USAGE_MODEM, info, isdn_tty_event_callback);
+		info->isdn_slot = slot;
+		isdn_slot_set_m_idx(slot, info->line);
+		slot->usage |= ISDN_USAGE_MODEM;
+		slot->priv = info;
+		slot->event_cb = isdn_tty_event_callback;
 		info->last_dir = 1;
 		info->last_l2 = l2;
 		strcpy(info->last_num, n);
@@ -793,13 +795,13 @@ void
 isdn_tty_modem_hup(modem_info * info, int local)
 {
 	isdn_ctrl cmd;
-	int slot;
+	struct isdn_slot *slot;
 
 	if (!info)
 		return;
 
 	slot = info->isdn_slot;
-	if (slot < 0)
+	if (!slot)
 		return;
 
 #ifdef ISDN_DEBUG_MODEM_HUP
@@ -848,9 +850,10 @@ isdn_tty_modem_hup(modem_info * info, int local)
 
 	info->emu.mdmreg[REG_RINGCNT] = 0;
 	skb_queue_purge(&info->rpqueue);
+	slot->priv = NULL;
+	slot->event_cb = NULL;
 	isdn_slot_free(slot);
-	isdn_slot_set_priv(slot, 0, NULL, NULL);
-	info->isdn_slot = -1;
+	info->isdn_slot = NULL;
 }
 
 /*
@@ -910,7 +913,7 @@ isdn_tty_resume(char *id, modem_info * info, atemu * m)
 	int l2 = m->mdmreg[REG_L2PROT];
 	isdn_ctrl cmd;
 	ulong flags;
-	int i;
+	struct isdn_slot *slot;
 	int j;
 	int l;
 
@@ -935,14 +938,16 @@ isdn_tty_resume(char *id, modem_info * info, atemu * m)
 	m->mdmreg[REG_SI1I] = si2bit[si];
 	save_flags(flags);
 	cli();
-	i = isdn_get_free_slot(usg, l2, m->mdmreg[REG_L3PROT], -1, -1, m->msn);
-	if (i < 0) {
+	slot = isdn_get_free_slot(usg, l2, m->mdmreg[REG_L3PROT], -1, -1, m->msn);
+	if (!slot) {
 		restore_flags(flags);
 		isdn_tty_modem_result(RESULT_NO_DIALTONE, info);
 	} else {
-		info->isdn_slot = i;
-		isdn_slot_set_m_idx(i, info->line);
-		isdn_slot_set_priv(i, ISDN_USAGE_MODEM, info, isdn_tty_event_callback);
+		info->isdn_slot = slot;
+		isdn_slot_set_m_idx(slot, info->line);
+		slot->usage |= ISDN_USAGE_MODEM;
+		slot->priv = info;
+		slot->event_cb = isdn_tty_event_callback;
 		info->last_dir = 1;
 //		strcpy(info->last_num, n);
 		restore_flags(flags);
@@ -981,7 +986,7 @@ isdn_tty_send_msg(modem_info * info, atemu * m, char *msg)
 	int l2 = m->mdmreg[REG_L2PROT];
 	isdn_ctrl cmd;
 	ulong flags;
-	int i;
+	struct isdn_slot *slot;
 	int j;
 	int l;
 
@@ -1010,14 +1015,16 @@ isdn_tty_send_msg(modem_info * info, atemu * m, char *msg)
 	m->mdmreg[REG_SI1I] = si2bit[si];
 	save_flags(flags);
 	cli();
-	i = isdn_get_free_slot(usg, l2, m->mdmreg[REG_L3PROT], -1, -1, m->msn);
-	if (i < 0) {
+	slot = isdn_get_free_slot(usg, l2, m->mdmreg[REG_L3PROT], -1, -1, m->msn);
+	if (!slot) {
 		restore_flags(flags);
 		isdn_tty_modem_result(RESULT_NO_DIALTONE, info);
 	} else {
-		info->isdn_slot = i;
-		isdn_slot_set_m_idx(i, info->line);
-		isdn_slot_set_priv(i, ISDN_USAGE_MODEM, info, isdn_tty_event_callback);
+		info->isdn_slot = slot;
+		isdn_slot_set_m_idx(slot, info->line);
+		slot->usage |= ISDN_USAGE_MODEM;
+		slot->priv = info;
+		slot->event_cb = isdn_tty_event_callback;
 		info->last_dir = 1;
 		restore_flags(flags);
 		info->last_l2 = l2;
@@ -1212,7 +1219,7 @@ isdn_tty_write(struct tty_struct *tty, int from_user, const u_char * buf, int co
 		c = count;
 		if (c > info->xmit_size - info->xmit_count)
 			c = info->xmit_size - info->xmit_count;
-		if (info->isdn_slot >= 0 && c > isdn_slot_maxbufsize(info->isdn_slot))
+		if (info->isdn_slot && c > isdn_slot_maxbufsize(info->isdn_slot))
 			c = isdn_slot_maxbufsize(info->isdn_slot);
 		if (c <= 0)
 			break;
@@ -2123,7 +2130,7 @@ isdn_tty_init(void)
 		info->normal_termios = m->tty_modem.init_termios;
 		init_waitqueue_head(&info->open_wait);
 		init_waitqueue_head(&info->close_wait);
-		info->isdn_slot = -1;
+		info->isdn_slot = NULL;
 		skb_queue_head_init(&info->rpqueue);
 		info->xmit_size = ISDN_SERIAL_XMIT_SIZE;
 		skb_queue_head_init(&info->xmit_queue);
@@ -2240,7 +2247,7 @@ isdn_tty_match_icall(char *cid, atemu *emu, int di)
  *      CID is longer.
  */
 int
-isdn_tty_find_icall(int di, int ch, int sl, setup_parm *setup)
+isdn_tty_find_icall(struct isdn_slot *slot, setup_parm *setup)
 {
 	char *eaz;
 	int i;
@@ -2285,17 +2292,18 @@ isdn_tty_find_icall(int di, int ch, int sl, setup_parm *setup)
 #ifndef FIX_FILE_TRANSFER
 				(info->flags & ISDN_ASYNC_NORMAL_ACTIVE) &&
 #endif
-				(info->isdn_slot == -1) &&
-				(USG_NONE(isdn_slot_usage(sl)))) {
+				(!info->isdn_slot)) {
 				int matchret;
 
-				if ((matchret = isdn_tty_match_icall(eaz, &info->emu, di)) > wret)
+				if ((matchret = isdn_tty_match_icall(eaz, &info->emu, slot->di)) > wret)
 					wret = matchret;
 				if (!matchret) {                  /* EAZ is matching */
-					info->isdn_slot = sl;
-					isdn_slot_set_m_idx(sl, info->line);
-					isdn_slot_set_priv(sl, isdn_calc_usage(si1, info->emu.mdmreg[REG_L2PROT]), info, isdn_tty_event_callback);
-					strcpy(isdn_slot_num(sl), nr);
+					info->isdn_slot = slot;
+					isdn_slot_set_m_idx(slot, info->line);
+					slot->usage |= isdn_calc_usage(si1, info->emu.mdmreg[REG_L2PROT]);
+					slot->priv = info;
+					slot->event_cb = isdn_tty_event_callback;
+					strcpy(slot->num, nr);
 					strcpy(info->emu.cpn, eaz);
 					info->emu.mdmreg[REG_SI1I] = si2bit[si1];
 					info->emu.mdmreg[REG_PLAN] = setup->plan;
@@ -2321,13 +2329,13 @@ isdn_tty_find_icall(int di, int ch, int sl, setup_parm *setup)
 	(info->flags & (ISDN_ASYNC_NORMAL_ACTIVE | ISDN_ASYNC_CALLOUT_ACTIVE))
 
 static int
-isdn_tty_stat_callback(int i, isdn_ctrl *c)
+isdn_tty_stat_callback(struct isdn_slot *slot, isdn_ctrl *c)
 {
 	isdn_ctrl cmd;
 	modem_info *info;
 	char *e;
 
-	info = isdn_slot_priv(i);
+	info = slot->priv;
 	if (1) {
 		switch (c->command) {
                         case ISDN_STAT_CINF:
@@ -2423,14 +2431,14 @@ isdn_tty_stat_callback(int i, isdn_ctrl *c)
 						info->last_dir = 0;
 					info->dialing = 0;
 					info->rcvsched = 1;
-					if (USG_MODEM(isdn_slot_usage(i))) {
+					if (USG_MODEM(slot->usage)) {
 						if (info->emu.mdmreg[REG_L2PROT] == ISDN_PROTO_L2_MODEM) {
 							strcpy(info->emu.connmsg, c->parm.num);
 							isdn_tty_modem_result(RESULT_CONNECT, info);
 						} else
 							isdn_tty_modem_result(RESULT_CONNECT64000, info);
 					}
-					if (USG_VOICE(isdn_slot_usage(i)))
+					if (USG_VOICE(slot->usage))
 						isdn_tty_modem_result(RESULT_VCON, info);
 					return 1;
 				}
@@ -2570,7 +2578,7 @@ isdn_tty_at_cout(char *msg, modem_info * info)
 static void
 isdn_tty_on_hook(modem_info * info)
 {
-	if (info->isdn_slot >= 0) {
+	if (info->isdn_slot) {
 #ifdef ISDN_DEBUG_MODEM_HUP
 		printk(KERN_DEBUG "Mhup in isdn_tty_on_hook\n");
 #endif
diff --git a/drivers/isdn/i4l/isdn_tty.h b/drivers/isdn/i4l/isdn_tty.h
index 96c14d1765e0..060302c6a589 100644
--- a/drivers/isdn/i4l/isdn_tty.h
+++ b/drivers/isdn/i4l/isdn_tty.h
@@ -104,7 +104,7 @@ extern void isdn_tty_carrier_timeout(void);
 extern void isdn_tty_modem_xmit(void);
 extern int isdn_tty_init(void);
 extern void isdn_tty_readmodem(void);
-extern int isdn_tty_find_icall(int, int, int, setup_parm *);
+extern int isdn_tty_find_icall(struct isdn_slot *slot, setup_parm *setup);
 extern void isdn_tty_cleanup_xmit(modem_info *);
 extern int isdn_tty_capi_facility(capi_msg *cm); 
 extern void isdn_tty_at_cout(char *, modem_info *);
diff --git a/drivers/isdn/i4l/isdn_ttyfax.c b/drivers/isdn/i4l/isdn_ttyfax.c
index bfe49a1400a2..35142304fdbe 100644
--- a/drivers/isdn/i4l/isdn_ttyfax.c
+++ b/drivers/isdn/i4l/isdn_ttyfax.c
@@ -53,7 +53,7 @@ isdn_tty_fax_modem_result(int code, modem_info * info)
 		case 2:	/* +FCON */
 			/* Append CPN, if enabled */
 			if ((m->mdmreg[REG_CPNFCON] & BIT_CPNFCON) &&
-				(!(isdn_slot_usage(info->isdn_slot) & ISDN_USAGE_OUTGOING))) {
+				(!(info->isdn_slot->usage & ISDN_USAGE_OUTGOING))) {
 				sprintf(rs, "/%s", m->cpn);
 				isdn_tty_at_cout(rs, info);
 			}
@@ -301,7 +301,8 @@ isdn_tty_cmd_FCLASS1(char **p, modem_info * info)
 	static char *cmd[] =
 	{"AE", "TS", "RS", "TM", "RM", "TH", "RH"};
 	isdn_ctrl c;
-	int par, i;
+	int par;
+	struct isdn_slot *slot;
 	long flags;
 
 	for (c.parm.aux.cmd = 0; c.parm.aux.cmd < 7; c.parm.aux.cmd++)
@@ -343,7 +344,7 @@ isdn_tty_cmd_FCLASS1(char **p, modem_info * info)
 	printk(KERN_DEBUG "isdn_tty_cmd_FCLASS1 %d/%d/%d)\n",
 	       c.parm.aux.cmd, c.parm.aux.subcmd, c.parm.aux.para[0]);
 #endif
-	if (info->isdn_slot < 0) {
+	if (!info->isdn_slot) {
 		save_flags(flags);
 		cli();
 		if ((c.parm.aux.subcmd == AT_EQ_VALUE) ||
@@ -352,18 +353,18 @@ isdn_tty_cmd_FCLASS1(char **p, modem_info * info)
 			PARSE_ERROR1;
 		}
 		/* get a temporary connection to the first free fax driver */
-		i = isdn_get_free_slot(ISDN_USAGE_FAX, ISDN_PROTO_L2_FAX,
+		slot = isdn_get_free_slot(ISDN_USAGE_FAX, ISDN_PROTO_L2_FAX,
 				       ISDN_PROTO_L3_FCLASS1, -1, -1, "00");
-		if (i < 0) {
+		if (!slot) {
 			restore_flags(flags);
 			PARSE_ERROR1;
 		}
-		info->isdn_slot = i;
-		isdn_slot_set_m_idx(i, info->line);
-		isdn_slot_command(info->isdn_slot, ISDN_CMD_FAXCMD, &c);
-		isdn_slot_free(info->isdn_slot);
-		isdn_slot_set_m_idx(i, -1);
-		info->isdn_slot = -1;
+		info->isdn_slot = slot;
+		isdn_slot_set_m_idx(slot, info->line);
+		isdn_slot_command(slot, ISDN_CMD_FAXCMD, &c);
+		isdn_slot_free(slot);
+		isdn_slot_set_m_idx(slot, -1);
+		info->isdn_slot = NULL;
 		restore_flags(flags);
 	} else {
 		isdn_slot_command(info->isdn_slot, ISDN_CMD_FAXCMD, &c);
diff --git a/drivers/isdn/i4l/isdn_v110.c b/drivers/isdn/i4l/isdn_v110.c
index ed2d8f12abf8..be702981df0e 100644
--- a/drivers/isdn/i4l/isdn_v110.c
+++ b/drivers/isdn/i4l/isdn_v110.c
@@ -512,11 +512,11 @@ buffer_full:
 
 
 void
-isdn_v110_open(int sl, struct isdn_v110 *iv110)
+isdn_v110_open(struct isdn_slot *slot, struct isdn_v110 *iv110)
 {	
 	isdn_v110_stream *v;
-	int hdrlen = isdn_slot_hdrlen(sl);
-	int maxsize = isdn_slot_maxbufsize(sl);
+	int hdrlen = isdn_slot_hdrlen(slot);
+	int maxsize = isdn_slot_maxbufsize(slot);
 
 	atomic_inc(&iv110->v110use);
 	switch (iv110->v110emu) {
@@ -533,7 +533,7 @@ isdn_v110_open(int sl, struct isdn_v110 *iv110)
 	if ((v = iv110->v110)) {
 		while (v->SyncInit) {
 			struct sk_buff *skb = isdn_v110_sync(v);
-			if (isdn_slot_write(sl, skb) <= 0) {
+			if (isdn_slot_write(slot, skb) <= 0) {
 				dev_kfree_skb(skb);
 				/* Unable to send, try later */
 				break;
@@ -547,7 +547,7 @@ isdn_v110_open(int sl, struct isdn_v110 *iv110)
 }
 
 void
-isdn_v110_close(int sl, struct isdn_v110 *iv110)
+isdn_v110_close(struct isdn_slot *slot, struct isdn_v110 *iv110)
 {
 	while (1) {
 		atomic_inc(&iv110->v110use);
@@ -560,7 +560,7 @@ isdn_v110_close(int sl, struct isdn_v110 *iv110)
 }
 
 int
-isdn_v110_bsent(int sl, struct isdn_v110 *iv110)
+isdn_v110_bsent(struct isdn_slot *slot, struct isdn_v110 *iv110)
 {
 	isdn_v110_stream *v = iv110->v110;
 	int i, ret;
@@ -587,7 +587,7 @@ isdn_v110_bsent(int sl, struct isdn_v110 *iv110)
 		else
 			skb = isdn_v110_idle(v);
 		if (skb) {
-			if (isdn_slot_write(sl, skb) <= 0) {
+			if (isdn_slot_write(slot, skb) <= 0) {
 				dev_kfree_skb(skb);
 				break;
 			} else {
diff --git a/drivers/isdn/i4l/isdn_v110.h b/drivers/isdn/i4l/isdn_v110.h
index 77a947481166..36b404f56f48 100644
--- a/drivers/isdn/i4l/isdn_v110.h
+++ b/drivers/isdn/i4l/isdn_v110.h
@@ -26,10 +26,10 @@ extern struct sk_buff *isdn_v110_encode(isdn_v110_stream *, struct sk_buff *);
  */
 extern struct sk_buff *isdn_v110_decode(isdn_v110_stream *, struct sk_buff *);
 
-extern void isdn_v110_open(int sl, struct isdn_v110 *iv110);
+extern void isdn_v110_open(struct isdn_slot *slot, struct isdn_v110 *iv110);
 
-extern void isdn_v110_close(int sl, struct isdn_v110 *iv110);
+extern void isdn_v110_close(struct isdn_slot *slot, struct isdn_v110 *iv110);
 
-extern int  isdn_v110_bsent(int sl, struct isdn_v110 *iv110);
+extern int  isdn_v110_bsent(struct isdn_slot *slot, struct isdn_v110 *iv110);
 
 #endif
diff --git a/include/linux/isdn.h b/include/linux/isdn.h
index 4ab5ac856cc9..c5352e5d1194 100644
--- a/include/linux/isdn.h
+++ b/include/linux/isdn.h
@@ -327,7 +327,7 @@ typedef struct modem_info {
 					 /* 2 = B-Channel is up, deliver d.*/
   int                   dialing;         /* Dial in progress or ATA        */
   int                   rcvsched;        /* Receive needs schedule         */
-  int                   isdn_slot;	 /* Index to isdn-driver/channel   */
+  struct isdn_slot     *isdn_slot;	 /* Ptr to isdn-driver/channel     */
   struct sk_buff_head   rpqueue;         /* Queue of recv'd packets        */
   int                   rcvcount;        /* Byte-counters for B rx         */
   int                   ncarrier;        /* Flag: schedule NO CARRIER      */