diff --git a/arch/ia64/hp/sim/simserial.c b/arch/ia64/hp/sim/simserial.c
index f513dc02bb87..2a2fe0c56119 100644
--- a/arch/ia64/hp/sim/simserial.c
+++ b/arch/ia64/hp/sim/simserial.c
@@ -769,13 +769,10 @@ startup(struct async_struct *info)
 static int rs_open(struct tty_struct *tty, struct file * filp)
 {
 	struct async_struct	*info;
-	int			retval, line;
+	int			retval;
 	unsigned long		page;
 
-	line = tty->index;
-	if ((line < 0) || (line >= NR_PORTS))
-		return -ENODEV;
-	retval = get_async_struct(line, &info);
+	retval = get_async_struct(tty->index, &info);
 	if (retval)
 		return retval;
 	tty->driver_data = info;
@@ -920,7 +917,7 @@ simrs_init (void)
 	if (!ia64_platform_is("hpsim"))
 		return -ENODEV;
 
-	hp_simserial_driver = alloc_tty_driver(1);
+	hp_simserial_driver = alloc_tty_driver(NR_PORTS);
 	if (!hp_simserial_driver)
 		return -ENOMEM;
 
diff --git a/arch/xtensa/platforms/iss/console.c b/arch/xtensa/platforms/iss/console.c
index 247e9d40a52e..19a802a13096 100644
--- a/arch/xtensa/platforms/iss/console.c
+++ b/arch/xtensa/platforms/iss/console.c
@@ -68,11 +68,6 @@ static void rs_poll(unsigned long);
 
 static int rs_open(struct tty_struct *tty, struct file * filp)
 {
-	int line = tty->index;
-
-	if ((line < 0) || (line >= SERIAL_MAX_NUM_LINES))
-		return -ENODEV;
-
 	spin_lock(&timer_lock);
 
 	if (tty->count == 1) {
@@ -101,6 +96,7 @@ static void rs_close(struct tty_struct *tty, struct file * filp)
 {
 	spin_lock(&timer_lock);
 	if (tty->count == 1)
+		/* this will cause a deadlock if the timer ticks right now */
 		del_timer_sync(&serial_timer);
 	spin_unlock(&timer_lock);
 }
@@ -210,7 +206,7 @@ static const struct tty_operations serial_ops = {
 
 int __init rs_init(void)
 {
-	serial_driver = alloc_tty_driver(1);
+	serial_driver = alloc_tty_driver(SERIAL_MAX_NUM_LINES);
 
 	printk ("%s %s\n", serial_name, serial_version);
 
diff --git a/drivers/char/pcmcia/synclink_cs.c b/drivers/char/pcmcia/synclink_cs.c
index c3bcb1221e6b..f6453df4921c 100644
--- a/drivers/char/pcmcia/synclink_cs.c
+++ b/drivers/char/pcmcia/synclink_cs.c
@@ -2484,7 +2484,7 @@ static int mgslpc_open(struct tty_struct *tty, struct file * filp)
 
 	/* verify range of specified line number */
 	line = tty->index;
-	if ((line < 0) || (line >= mgslpc_device_count)) {
+	if (line >= mgslpc_device_count) {
 		printk("%s(%d):mgslpc_open with invalid line #%d.\n",
 			__FILE__,__LINE__,line);
 		return -ENODEV;
diff --git a/drivers/isdn/capi/capi.c b/drivers/isdn/capi/capi.c
index baf08eba495c..3a7905b06e53 100644
--- a/drivers/isdn/capi/capi.c
+++ b/drivers/isdn/capi/capi.c
@@ -1013,8 +1013,7 @@ static const struct file_operations capi_fops =
 static int
 capinc_tty_install(struct tty_driver *driver, struct tty_struct *tty)
 {
-	int idx = tty->index;
-	struct capiminor *mp = capiminor_get(idx);
+	struct capiminor *mp = capiminor_get(tty->index);
 	int ret = tty_standard_install(driver, tty);
 
 	if (ret == 0)
diff --git a/drivers/isdn/gigaset/common.c b/drivers/isdn/gigaset/common.c
index db621db67f61..ac0186e54bf4 100644
--- a/drivers/isdn/gigaset/common.c
+++ b/drivers/isdn/gigaset/common.c
@@ -1051,8 +1051,6 @@ static struct cardstate *gigaset_get_cs_by_minor(unsigned minor)
 
 struct cardstate *gigaset_get_cs_by_tty(struct tty_struct *tty)
 {
-	if (tty->index < 0 || tty->index >= tty->driver->num)
-		return NULL;
 	return gigaset_get_cs_by_minor(tty->index + tty->driver->minor_start);
 }
 
diff --git a/drivers/isdn/i4l/isdn_tty.c b/drivers/isdn/i4l/isdn_tty.c
index 2c26b64ebbea..ac4840124bc0 100644
--- a/drivers/isdn/i4l/isdn_tty.c
+++ b/drivers/isdn/i4l/isdn_tty.c
@@ -1590,12 +1590,9 @@ static int
 isdn_tty_open(struct tty_struct *tty, struct file *filp)
 {
 	modem_info *info;
-	int retval, line;
+	int retval;
 
-	line = tty->index;
-	if (line < 0 || line >= ISDN_MAX_CHANNELS)
-		return -ENODEV;
-	info = &dev->mdm.info[line];
+	info = &dev->mdm.info[tty->index];
 	if (isdn_tty_paranoia_check(info, tty->name, "isdn_tty_open"))
 		return -ENODEV;
 	if (!try_module_get(info->owner)) {
diff --git a/drivers/s390/char/con3215.c b/drivers/s390/char/con3215.c
index fe916bfd60f2..ed23fec7abbe 100644
--- a/drivers/s390/char/con3215.c
+++ b/drivers/s390/char/con3215.c
@@ -926,13 +926,9 @@ console_initcall(con3215_init);
 static int tty3215_open(struct tty_struct *tty, struct file * filp)
 {
 	struct raw3215_info *raw;
-	int retval, line;
+	int retval;
 
-	line = tty->index;
-	if ((line < 0) || (line >= NR_3215))
-		return -ENODEV;
-
-	raw = raw3215[line];
+	raw = raw3215[tty->index];
 	if (raw == NULL)
 		return -ENODEV;
 
diff --git a/drivers/tty/amiserial.c b/drivers/tty/amiserial.c
index b42f00d987ae..753286257554 100644
--- a/drivers/tty/amiserial.c
+++ b/drivers/tty/amiserial.c
@@ -1768,13 +1768,9 @@ static int get_async_struct(int line, struct async_struct **ret_info)
 static int rs_open(struct tty_struct *tty, struct file * filp)
 {
 	struct async_struct	*info;
-	int 			retval, line;
+	int retval;
 
-	line = tty->index;
-	if ((line < 0) || (line >= NR_PORTS)) {
-		return -ENODEV;
-	}
-	retval = get_async_struct(line, &info);
+	retval = get_async_struct(tty->index, &info);
 	if (retval) {
 		return retval;
 	}
@@ -1964,7 +1960,7 @@ static int __init amiga_serial_probe(struct platform_device *pdev)
 	struct serial_state * state;
 	int error;
 
-	serial_driver = alloc_tty_driver(1);
+	serial_driver = alloc_tty_driver(NR_PORTS);
 	if (!serial_driver)
 		return -ENOMEM;
 
diff --git a/drivers/tty/cyclades.c b/drivers/tty/cyclades.c
index bc7b5a5650ba..e61cabdd69df 100644
--- a/drivers/tty/cyclades.c
+++ b/drivers/tty/cyclades.c
@@ -1515,13 +1515,9 @@ static void cy_shutdown(struct cyclades_port *info, struct tty_struct *tty)
 static int cy_open(struct tty_struct *tty, struct file *filp)
 {
 	struct cyclades_port *info;
-	unsigned int i, line;
+	unsigned int i, line = tty->index;
 	int retval;
 
-	line = tty->index;
-	if (tty->index < 0 || NR_PORTS <= line)
-		return -ENODEV;
-
 	for (i = 0; i < NR_CARDS; i++)
 		if (line < cy_card[i].first_line + cy_card[i].nports &&
 				line >= cy_card[i].first_line)
diff --git a/drivers/tty/hvc/hvcs.c b/drivers/tty/hvc/hvcs.c
index da0aa476804d..d23759183b47 100644
--- a/drivers/tty/hvc/hvcs.c
+++ b/drivers/tty/hvc/hvcs.c
@@ -1090,27 +1090,23 @@ static int hvcs_enable_device(struct hvcs_struct *hvcsd, uint32_t unit_address,
  */
 static struct hvcs_struct *hvcs_get_by_index(int index)
 {
-	struct hvcs_struct *hvcsd = NULL;
+	struct hvcs_struct *hvcsd;
 	unsigned long flags;
 
 	spin_lock(&hvcs_structs_lock);
-	/* We can immediately discard OOB requests */
-	if (index >= 0 && index < HVCS_MAX_SERVER_ADAPTERS) {
-		list_for_each_entry(hvcsd, &hvcs_structs, next) {
-			spin_lock_irqsave(&hvcsd->lock, flags);
-			if (hvcsd->index == index) {
-				kref_get(&hvcsd->kref);
-				spin_unlock_irqrestore(&hvcsd->lock, flags);
-				spin_unlock(&hvcs_structs_lock);
-				return hvcsd;
-			}
+	list_for_each_entry(hvcsd, &hvcs_structs, next) {
+		spin_lock_irqsave(&hvcsd->lock, flags);
+		if (hvcsd->index == index) {
+			kref_get(&hvcsd->kref);
 			spin_unlock_irqrestore(&hvcsd->lock, flags);
+			spin_unlock(&hvcs_structs_lock);
+			return hvcsd;
 		}
-		hvcsd = NULL;
+		spin_unlock_irqrestore(&hvcsd->lock, flags);
 	}
-
 	spin_unlock(&hvcs_structs_lock);
-	return hvcsd;
+
+	return NULL;
 }
 
 /*
diff --git a/drivers/tty/hvc/hvsi.c b/drivers/tty/hvc/hvsi.c
index 60bc45164189..a7488b748647 100644
--- a/drivers/tty/hvc/hvsi.c
+++ b/drivers/tty/hvc/hvsi.c
@@ -737,14 +737,11 @@ static int hvsi_open(struct tty_struct *tty, struct file *filp)
 {
 	struct hvsi_struct *hp;
 	unsigned long flags;
-	int line = tty->index;
 	int ret;
 
 	pr_debug("%s\n", __func__);
 
-	if (line < 0 || line >= hvsi_count)
-		return -ENODEV;
-	hp = &hvsi_ports[line];
+	hp = &hvsi_ports[tty->index];
 
 	tty->driver_data = hp;
 
diff --git a/drivers/tty/isicom.c b/drivers/tty/isicom.c
index b3a28b5f02ad..03c14979accf 100644
--- a/drivers/tty/isicom.c
+++ b/drivers/tty/isicom.c
@@ -849,8 +849,6 @@ static struct tty_port *isicom_find_port(struct tty_struct *tty)
 	unsigned int board;
 	int line = tty->index;
 
-	if (line < 0 || line > PORT_COUNT-1)
-		return NULL;
 	board = BOARD(line);
 	card = &isi_card[board];
 
diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 260d03123524..17ff377e4129 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -1010,8 +1010,6 @@ static int mxser_open(struct tty_struct *tty, struct file *filp)
 	line = tty->index;
 	if (line == MXSER_PORTS)
 		return 0;
-	if (line < 0 || line > MXSER_PORTS)
-		return -ENODEV;
 	info = &mxser_boards[line / MXSER_PORTS_PER_BOARD].ports[line % MXSER_PORTS_PER_BOARD];
 	if (!info->ioaddr)
 		return -ENODEV;
diff --git a/drivers/tty/rocket.c b/drivers/tty/rocket.c
index b088e1ea4331..777d5f9cf6cc 100644
--- a/drivers/tty/rocket.c
+++ b/drivers/tty/rocket.c
@@ -892,12 +892,12 @@ static int rp_open(struct tty_struct *tty, struct file *filp)
 {
 	struct r_port *info;
 	struct tty_port *port;
-	int line = 0, retval;
+	int retval;
 	CHANNEL_t *cp;
 	unsigned long page;
 
-	line = tty->index;
-	if (line < 0 || line >= MAX_RP_PORTS || ((info = rp_table[line]) == NULL))
+	info = rp_table[tty->index];
+	if (info == NULL)
 		return -ENXIO;
 	port = &info->port;
 	
diff --git a/drivers/tty/serial/68328serial.c b/drivers/tty/serial/68328serial.c
index a88ef9782a4f..7398390e7e65 100644
--- a/drivers/tty/serial/68328serial.c
+++ b/drivers/tty/serial/68328serial.c
@@ -1190,14 +1190,9 @@ static int block_til_ready(struct tty_struct *tty, struct file * filp,
 int rs_open(struct tty_struct *tty, struct file * filp)
 {
 	struct m68k_serial	*info;
-	int 			retval, line;
+	int retval;
 
-	line = tty->index;
-	
-	if (line >= NR_PORTS || line < 0) /* we have exactly one */
-		return -ENODEV;
-
-	info = &m68k_soft[line];
+	info = &m68k_soft[tty->index];
 
 	if (serial_paranoia_check(info, tty->name, "rs_open"))
 		return -ENODEV;
diff --git a/drivers/tty/serial/crisv10.c b/drivers/tty/serial/crisv10.c
index 1dfba7b779c8..23d791696879 100644
--- a/drivers/tty/serial/crisv10.c
+++ b/drivers/tty/serial/crisv10.c
@@ -4105,20 +4105,11 @@ static int
 rs_open(struct tty_struct *tty, struct file * filp)
 {
 	struct e100_serial	*info;
-	int 			retval, line;
+	int 			retval;
 	unsigned long           page;
 	int                     allocated_resources = 0;
 
-	/* find which port we want to open */
-	line = tty->index;
-
-	if (line < 0 || line >= NR_PORTS)
-		return -ENODEV;
-
-	/* find the corresponding e100_serial struct in the table */
-	info = rs_table + line;
-
-	/* don't allow the opening of ports that are not enabled in the HW config */
+	info = rs_table + tty->index;
 	if (!info->enabled)
 		return -ENODEV;
 
@@ -4131,7 +4122,7 @@ rs_open(struct tty_struct *tty, struct file * filp)
 	tty->driver_data = info;
 	info->port.tty = tty;
 
-	info->port.tty->low_latency = (info->flags & ASYNC_LOW_LATENCY) ? 1 : 0;
+	tty->low_latency = !!(info->flags & ASYNC_LOW_LATENCY);
 
 	if (!tmp_buf) {
 		page = get_zeroed_page(GFP_KERNEL);
diff --git a/drivers/tty/synclink.c b/drivers/tty/synclink.c
index 2b2988c779c7..8e518da85fd5 100644
--- a/drivers/tty/synclink.c
+++ b/drivers/tty/synclink.c
@@ -3381,7 +3381,7 @@ static int mgsl_open(struct tty_struct *tty, struct file * filp)
 
 	/* verify range of specified line number */	
 	line = tty->index;
-	if ((line < 0) || (line >= mgsl_device_count)) {
+	if (line >= mgsl_device_count) {
 		printk("%s(%d):mgsl_open with invalid line #%d.\n",
 			__FILE__,__LINE__,line);
 		return -ENODEV;
diff --git a/drivers/tty/synclink_gt.c b/drivers/tty/synclink_gt.c
index a8b66be37e6e..6bee4907c6a5 100644
--- a/drivers/tty/synclink_gt.c
+++ b/drivers/tty/synclink_gt.c
@@ -654,7 +654,7 @@ static int open(struct tty_struct *tty, struct file *filp)
 	unsigned long flags;
 
 	line = tty->index;
-	if ((line < 0) || (line >= slgt_device_count)) {
+	if (line >= slgt_device_count) {
 		DBGERR(("%s: open with invalid line #%d.\n", driver_name, line));
 		return -ENODEV;
 	}
diff --git a/drivers/tty/synclinkmp.c b/drivers/tty/synclinkmp.c
index ddabb61c85ba..4fb6c4b31b79 100644
--- a/drivers/tty/synclinkmp.c
+++ b/drivers/tty/synclinkmp.c
@@ -721,7 +721,7 @@ static int open(struct tty_struct *tty, struct file *filp)
 	unsigned long flags;
 
 	line = tty->index;
-	if ((line < 0) || (line >= synclinkmp_device_count)) {
+	if (line >= synclinkmp_device_count) {
 		printk("%s(%d): open with invalid line #%d.\n",
 			__FILE__,__LINE__,line);
 		return -ENODEV;
diff --git a/drivers/usb/gadget/u_serial.c b/drivers/usb/gadget/u_serial.c
index 490b01dd5d60..6c23938d2711 100644
--- a/drivers/usb/gadget/u_serial.c
+++ b/drivers/usb/gadget/u_serial.c
@@ -725,9 +725,6 @@ static int gs_open(struct tty_struct *tty, struct file *file)
 	struct gs_port	*port;
 	int		status;
 
-	if (port_num < 0 || port_num >= n_ports)
-		return -ENXIO;
-
 	do {
 		mutex_lock(&ports[port_num].lock);
 		port = ports[port_num].port;
diff --git a/net/irda/ircomm/ircomm_tty.c b/net/irda/ircomm/ircomm_tty.c
index 828f88603d6c..6b9d5a0e42f9 100644
--- a/net/irda/ircomm/ircomm_tty.c
+++ b/net/irda/ircomm/ircomm_tty.c
@@ -365,16 +365,12 @@ static int ircomm_tty_block_til_ready(struct ircomm_tty_cb *self,
 static int ircomm_tty_open(struct tty_struct *tty, struct file *filp)
 {
 	struct ircomm_tty_cb *self;
-	unsigned int line;
+	unsigned int line = tty->index;
 	unsigned long	flags;
 	int ret;
 
 	IRDA_DEBUG(2, "%s()\n", __func__ );
 
-	line = tty->index;
-	if (line >= IRCOMM_TTY_PORTS)
-		return -ENODEV;
-
 	/* Check if instance already exists */
 	self = hashbin_lock_find(ircomm_tty, line, NULL);
 	if (!self) {