Merge branch 'for-next' of git://github.com/rydberg/linux into next

Pull in changes from Henrik: "a trivial MT documentation fix".

71 files changed, 1630 insertions, 1362 deletions

diff --git a/drivers/tty/amiserial.c b/drivers/tty/amiserial.c
index fc700342d43..083710e0236 100644
--- a/drivers/tty/amiserial.c
+++ b/drivers/tty/amiserial.c
@@ -1798,19 +1798,7 @@ static struct platform_driver amiga_serial_driver = {
 	},
 };
 
-static int __init amiga_serial_init(void)
-{
-	return platform_driver_probe(&amiga_serial_driver, amiga_serial_probe);
-}
-
-module_init(amiga_serial_init);
-
-static void __exit amiga_serial_exit(void)
-{
-	platform_driver_unregister(&amiga_serial_driver);
-}
-
-module_exit(amiga_serial_exit);
+module_platform_driver_probe(amiga_serial_driver, amiga_serial_probe);
 
 
 #if defined(CONFIG_SERIAL_CONSOLE) && !defined(MODULE)
diff --git a/drivers/tty/cyclades.c b/drivers/tty/cyclades.c
index 345bd0e0884..33f83fee9fa 100644
--- a/drivers/tty/cyclades.c
+++ b/drivers/tty/cyclades.c
@@ -1124,14 +1124,8 @@ static void cyz_handle_cmd(struct cyclades_card *cinfo)
 					readl(&info->u.cyz.ch_ctrl->rs_status);
 				if (dcd & C_RS_DCD)
 					wake_up_interruptible(&info->port.open_wait);
-				else {
-					struct tty_struct *tty;
-					tty = tty_port_tty_get(&info->port);
-					if (tty) {
-						tty_hangup(tty);
-						tty_kref_put(tty);
-					}
-				}
+				else
+					tty_port_tty_hangup(&info->port, false);
 			}
 			break;
 		case C_CM_MCTS:
diff --git a/drivers/tty/ehv_bytechan.c b/drivers/tty/ehv_bytechan.c
index ed92622b894..9bffcec5ad8 100644
--- a/drivers/tty/ehv_bytechan.c
+++ b/drivers/tty/ehv_bytechan.c
@@ -472,13 +472,9 @@ static void ehv_bc_tx_dequeue(struct ehv_bc_data *bc)
 static irqreturn_t ehv_bc_tty_tx_isr(int irq, void *data)
 {
 	struct ehv_bc_data *bc = data;
-	struct tty_struct *ttys = tty_port_tty_get(&bc->port);
 
 	ehv_bc_tx_dequeue(bc);
-	if (ttys) {
-		tty_wakeup(ttys);
-		tty_kref_put(ttys);
-	}
+	tty_port_tty_wakeup(&bc->port);
 
 	return IRQ_HANDLED;
 }
@@ -863,6 +859,7 @@ error:
  */
 static void __exit ehv_bc_exit(void)
 {
+	platform_driver_unregister(&ehv_bc_tty_driver);
 	tty_unregister_driver(ehv_bc_driver);
 	put_tty_driver(ehv_bc_driver);
 	kfree(bcs);
diff --git a/drivers/tty/hvc/hvsi.c b/drivers/tty/hvc/hvsi.c
index ef95a154854..41901997c0d 100644
--- a/drivers/tty/hvc/hvsi.c
+++ b/drivers/tty/hvc/hvsi.c
@@ -861,7 +861,6 @@ static void hvsi_write_worker(struct work_struct *work)
 {
 	struct hvsi_struct *hp =
 		container_of(work, struct hvsi_struct, writer.work);
-	struct tty_struct *tty;
 	unsigned long flags;
 #ifdef DEBUG
 	static long start_j = 0;
@@ -895,11 +894,7 @@ static void hvsi_write_worker(struct work_struct *work)
 		start_j = 0;
 #endif /* DEBUG */
 		wake_up_all(&hp->emptyq);
-		tty = tty_port_tty_get(&hp->port);
-		if (tty) {
-			tty_wakeup(tty);
-			tty_kref_put(tty);
-		}
+		tty_port_tty_wakeup(&hp->port);
 	}
 
 out:
diff --git a/drivers/tty/ipwireless/hardware.c b/drivers/tty/ipwireless/hardware.c
index 97a511f4185..2c14842541d 100644
--- a/drivers/tty/ipwireless/hardware.c
+++ b/drivers/tty/ipwireless/hardware.c
@@ -1732,8 +1732,7 @@ void ipwireless_hardware_free(struct ipw_hardware *hw)
 	flush_work(&hw->work_rx);
 
 	for (i = 0; i < NL_NUM_OF_ADDRESSES; i++)
-		if (hw->packet_assembler[i] != NULL)
-			kfree(hw->packet_assembler[i]);
+		kfree(hw->packet_assembler[i]);
 
 	for (i = 0; i < NL_NUM_OF_PRIORITIES; i++)
 		list_for_each_entry_safe(tp, tq, &hw->tx_queue[i], queue) {
diff --git a/drivers/tty/moxa.c b/drivers/tty/moxa.c
index adeac255e52..1deaca4674e 100644
--- a/drivers/tty/moxa.c
+++ b/drivers/tty/moxa.c
@@ -913,16 +913,12 @@ static void moxa_board_deinit(struct moxa_board_conf *brd)
 
 	/* pci hot-un-plug support */
 	for (a = 0; a < brd->numPorts; a++)
-		if (brd->ports[a].port.flags & ASYNC_INITIALIZED) {
-			struct tty_struct *tty = tty_port_tty_get(
-						&brd->ports[a].port);
-			if (tty) {
-				tty_hangup(tty);
-				tty_kref_put(tty);
-			}
-		}
+		if (brd->ports[a].port.flags & ASYNC_INITIALIZED)
+			tty_port_tty_hangup(&brd->ports[a].port, false);
+
 	for (a = 0; a < MAX_PORTS_PER_BOARD; a++)
 		tty_port_destroy(&brd->ports[a].port);
+
 	while (1) {
 		opened = 0;
 		for (a = 0; a < brd->numPorts; a++)
@@ -1365,7 +1361,6 @@ static void moxa_hangup(struct tty_struct *tty)
 
 static void moxa_new_dcdstate(struct moxa_port *p, u8 dcd)
 {
-	struct tty_struct *tty;
 	unsigned long flags;
 	dcd = !!dcd;
 
@@ -1373,10 +1368,8 @@ static void moxa_new_dcdstate(struct moxa_port *p, u8 dcd)
 	if (dcd != p->DCDState) {
         	p->DCDState = dcd;
         	spin_unlock_irqrestore(&p->port.lock, flags);
-		tty = tty_port_tty_get(&p->port);
-		if (tty && !C_CLOCAL(tty) && !dcd)
-			tty_hangup(tty);
-		tty_kref_put(tty);
+		if (!dcd)
+			tty_port_tty_hangup(&p->port, true);
 	}
 	else
 		spin_unlock_irqrestore(&p->port.lock, flags);
diff --git a/drivers/tty/mxser.c b/drivers/tty/mxser.c
index 484b6a3c9b0..4c4a2367456 100644
--- a/drivers/tty/mxser.c
+++ b/drivers/tty/mxser.c
@@ -1084,6 +1084,10 @@ static void mxser_close(struct tty_struct *tty, struct file *filp)
 	mutex_lock(&port->mutex);
 	mxser_close_port(port);
 	mxser_flush_buffer(tty);
+	if (test_bit(ASYNCB_INITIALIZED, &port->flags)) {
+		if (C_HUPCL(tty))
+			tty_port_lower_dtr_rts(port);
+	}
 	mxser_shutdown_port(port);
 	clear_bit(ASYNCB_INITIALIZED, &port->flags);
 	mutex_unlock(&port->mutex);
@@ -1614,8 +1618,12 @@ static int mxser_ioctl_special(unsigned int cmd, void __user *argp)
 				if (ip->type == PORT_16550A)
 					me->fifo[p] = 1;
 
-				opmode = inb(ip->opmode_ioaddr)>>((p % 4) * 2);
-				opmode &= OP_MODE_MASK;
+				if (ip->board->chip_flag == MOXA_MUST_MU860_HWID) {
+					opmode = inb(ip->opmode_ioaddr)>>((p % 4) * 2);
+					opmode &= OP_MODE_MASK;
+				} else {
+					opmode = RS232_MODE;
+				}
 				me->iftype[p] = opmode;
 				mutex_unlock(&port->mutex);
 			}
@@ -1672,6 +1680,9 @@ static int mxser_ioctl(struct tty_struct *tty,
 		int shiftbit;
 		unsigned char val, mask;
 
+		if (info->board->chip_flag != MOXA_MUST_MU860_HWID)
+			return -EFAULT;
+
 		p = tty->index % 4;
 		if (cmd == MOXA_SET_OP_MODE) {
 			if (get_user(opmode, (int __user *) argp))
@@ -2643,9 +2654,9 @@ static int mxser_probe(struct pci_dev *pdev,
 				mxvar_sdriver, brd->idx + i, &pdev->dev);
 		if (IS_ERR(tty_dev)) {
 			retval = PTR_ERR(tty_dev);
-			for (i--; i >= 0; i--)
+			for (; i > 0; i--)
 				tty_unregister_device(mxvar_sdriver,
-					brd->idx + i);
+					brd->idx + i - 1);
 			goto err_relbrd;
 		}
 	}
@@ -2751,9 +2762,9 @@ static int __init mxser_module_init(void)
 			tty_dev = tty_port_register_device(&brd->ports[i].port,
 					mxvar_sdriver, brd->idx + i, NULL);
 			if (IS_ERR(tty_dev)) {
-				for (i--; i >= 0; i--)
+				for (; i > 0; i--)
 					tty_unregister_device(mxvar_sdriver,
-						brd->idx + i);
+						brd->idx + i - 1);
 				for (i = 0; i < brd->info->nports; i++)
 					tty_port_destroy(&brd->ports[i].port);
 				free_irq(brd->irq, brd);
diff --git a/drivers/tty/n_gsm.c b/drivers/tty/n_gsm.c
index 4a43ef5d796..642239015b4 100644
--- a/drivers/tty/n_gsm.c
+++ b/drivers/tty/n_gsm.c
@@ -1418,11 +1418,7 @@ static void gsm_dlci_close(struct gsm_dlci *dlci)
 		pr_debug("DLCI %d goes closed.\n", dlci->addr);
 	dlci->state = DLCI_CLOSED;
 	if (dlci->addr != 0) {
-		struct tty_struct  *tty = tty_port_tty_get(&dlci->port);
-		if (tty) {
-			tty_hangup(tty);
-			tty_kref_put(tty);
-		}
+		tty_port_tty_hangup(&dlci->port, false);
 		kfifo_reset(dlci->fifo);
 	} else
 		dlci->gsm->dead = 1;
@@ -2968,6 +2964,10 @@ static void gsmtty_close(struct tty_struct *tty, struct file *filp)
 	if (tty_port_close_start(&dlci->port, tty, filp) == 0)
 		goto out;
 	gsm_dlci_begin_close(dlci);
+	if (test_bit(ASYNCB_INITIALIZED, &dlci->port.flags)) {
+		if (C_HUPCL(tty))
+			tty_port_lower_dtr_rts(&dlci->port);
+	}
 	tty_port_close_end(&dlci->port, tty);
 	tty_port_tty_set(&dlci->port, NULL);
 out:
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c
index 05e72bea9b0..6c7fe90ad72 100644
--- a/drivers/tty/n_tty.c
+++ b/drivers/tty/n_tty.c
@@ -153,6 +153,12 @@ static void n_tty_set_room(struct tty_struct *tty)
 	if (left && !old_left) {
 		WARN_RATELIMIT(tty->port->itty == NULL,
 				"scheduling with invalid itty\n");
+		/* see if ldisc has been killed - if so, this means that
+		 * even though the ldisc has been halted and ->buf.work
+		 * cancelled, ->buf.work is about to be rescheduled
+		 */
+		WARN_RATELIMIT(test_bit(TTY_LDISC_HALTED, &tty->flags),
+			       "scheduling buffer work for halted ldisc\n");
 		schedule_work(&tty->port->buf.work);
 	}
 }
@@ -189,34 +195,17 @@ static void put_tty_queue(unsigned char c, struct n_tty_data *ldata)
 }
 
 /**
- *	check_unthrottle	-	allow new receive data
- *	@tty; tty device
- *
- *	Check whether to call the driver unthrottle functions
- *
- *	Can sleep, may be called under the atomic_read_lock mutex but
- *	this is not guaranteed.
- */
-static void check_unthrottle(struct tty_struct *tty)
-{
-	if (tty->count)
-		tty_unthrottle(tty);
-}
-
-/**
  *	reset_buffer_flags	-	reset buffer state
  *	@tty: terminal to reset
  *
- *	Reset the read buffer counters, clear the flags,
- *	and make sure the driver is unthrottled. Called
- *	from n_tty_open() and n_tty_flush_buffer().
+ *	Reset the read buffer counters and clear the flags.
+ *	Called from n_tty_open() and n_tty_flush_buffer().
  *
  *	Locking: tty_read_lock for read fields.
  */
 
-static void reset_buffer_flags(struct tty_struct *tty)
+static void reset_buffer_flags(struct n_tty_data *ldata)
 {
-	struct n_tty_data *ldata = tty->disc_data;
 	unsigned long flags;
 
 	raw_spin_lock_irqsave(&ldata->read_lock, flags);
@@ -229,36 +218,38 @@ static void reset_buffer_flags(struct tty_struct *tty)
 
 	ldata->canon_head = ldata->canon_data = ldata->erasing = 0;
 	bitmap_zero(ldata->read_flags, N_TTY_BUF_SIZE);
-	n_tty_set_room(tty);
+}
+
+static void n_tty_packet_mode_flush(struct tty_struct *tty)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&tty->ctrl_lock, flags);
+	if (tty->link->packet) {
+		tty->ctrl_status |= TIOCPKT_FLUSHREAD;
+		wake_up_interruptible(&tty->link->read_wait);
+	}
+	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
 }
 
 /**
  *	n_tty_flush_buffer	-	clean input queue
  *	@tty:	terminal device
  *
- *	Flush the input buffer. Called when the line discipline is
- *	being closed, when the tty layer wants the buffer flushed (eg
- *	at hangup) or when the N_TTY line discipline internally has to
- *	clean the pending queue (for example some signals).
+ *	Flush the input buffer. Called when the tty layer wants the
+ *	buffer flushed (eg at hangup) or when the N_TTY line discipline
+ *	internally has to clean the pending queue (for example some signals).
  *
  *	Locking: ctrl_lock, read_lock.
  */
 
 static void n_tty_flush_buffer(struct tty_struct *tty)
 {
-	unsigned long flags;
-	/* clear everything and unthrottle the driver */
-	reset_buffer_flags(tty);
-
-	if (!tty->link)
-		return;
+	reset_buffer_flags(tty->disc_data);
+	n_tty_set_room(tty);
 
-	spin_lock_irqsave(&tty->ctrl_lock, flags);
-	if (tty->link->packet) {
-		tty->ctrl_status |= TIOCPKT_FLUSHREAD;
-		wake_up_interruptible(&tty->link->read_wait);
-	}
-	spin_unlock_irqrestore(&tty->ctrl_lock, flags);
+	if (tty->link)
+		n_tty_packet_mode_flush(tty);
 }
 
 /**
@@ -1032,23 +1023,19 @@ static void eraser(unsigned char c, struct tty_struct *tty)
  *	isig		-	handle the ISIG optio
  *	@sig: signal
  *	@tty: terminal
- *	@flush: force flush
  *
- *	Called when a signal is being sent due to terminal input. This
- *	may caus terminal flushing to take place according to the termios
- *	settings and character used. Called from the driver receive_buf
- *	path so serialized.
+ *	Called when a signal is being sent due to terminal input.
+ *	Called from the driver receive_buf path so serialized.
  *
- *	Locking: ctrl_lock, read_lock (both via flush buffer)
+ *	Locking: ctrl_lock
  */
 
-static inline void isig(int sig, struct tty_struct *tty, int flush)
+static inline void isig(int sig, struct tty_struct *tty)
 {
-	if (tty->pgrp)
-		kill_pgrp(tty->pgrp, sig, 1);
-	if (flush || !L_NOFLSH(tty)) {
-		n_tty_flush_buffer(tty);
-		tty_driver_flush_buffer(tty);
+	struct pid *tty_pgrp = tty_get_pgrp(tty);
+	if (tty_pgrp) {
+		kill_pgrp(tty_pgrp, sig, 1);
+		put_pid(tty_pgrp);
 	}
 }
 
@@ -1069,7 +1056,11 @@ static inline void n_tty_receive_break(struct tty_struct *tty)
 	if (I_IGNBRK(tty))
 		return;
 	if (I_BRKINT(tty)) {
-		isig(SIGINT, tty, 1);
+		isig(SIGINT, tty);
+		if (!L_NOFLSH(tty)) {
+			n_tty_flush_buffer(tty);
+			tty_driver_flush_buffer(tty);
+		}
 		return;
 	}
 	if (I_PARMRK(tty)) {
@@ -1236,11 +1227,6 @@ static inline void n_tty_receive_char(struct tty_struct *tty, unsigned char c)
 		signal = SIGTSTP;
 		if (c == SUSP_CHAR(tty)) {
 send_signal:
-			/*
-			 * Note that we do not use isig() here because we want
-			 * the order to be:
-			 * 1) flush, 2) echo, 3) signal
-			 */
 			if (!L_NOFLSH(tty)) {
 				n_tty_flush_buffer(tty);
 				tty_driver_flush_buffer(tty);
@@ -1251,8 +1237,7 @@ send_signal:
 				echo_char(c, tty);
 				process_echoes(tty);
 			}
-			if (tty->pgrp)
-				kill_pgrp(tty->pgrp, signal, 1);
+			isig(signal, tty);
 			return;
 		}
 	}
@@ -1483,14 +1468,14 @@ static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp,
 	 * mode.  We don't want to throttle the driver if we're in
 	 * canonical mode and don't have a newline yet!
 	 */
-	if (tty->receive_room < TTY_THRESHOLD_THROTTLE)
-		tty_throttle(tty);
-
-        /* FIXME: there is a tiny race here if the receive room check runs
-           before the other work executes and empties the buffer (upping
-           the receiving room and unthrottling. We then throttle and get
-           stuck. This has been observed and traced down by Vincent Pillet/
-           We need to address this when we sort out out the rx path locking */
+	while (1) {
+		tty_set_flow_change(tty, TTY_THROTTLE_SAFE);
+		if (tty->receive_room >= TTY_THRESHOLD_THROTTLE)
+			break;
+		if (!tty_throttle_safe(tty))
+			break;
+	}
+	__tty_set_flow_change(tty, 0);
 }
 
 int is_ignored(int sig)
@@ -1588,6 +1573,14 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old)
 			ldata->real_raw = 0;
 	}
 	n_tty_set_room(tty);
+	/*
+	 * Fix tty hang when I_IXON(tty) is cleared, but the tty
+	 * been stopped by STOP_CHAR(tty) before it.
+	 */
+	if (!I_IXON(tty) && old && (old->c_iflag & IXON) && !tty->flow_stopped) {
+		start_tty(tty);
+	}
+
 	/* The termios change make the tty ready for I/O */
 	wake_up_interruptible(&tty->write_wait);
 	wake_up_interruptible(&tty->read_wait);
@@ -1607,7 +1600,9 @@ static void n_tty_close(struct tty_struct *tty)
 {
 	struct n_tty_data *ldata = tty->disc_data;
 
-	n_tty_flush_buffer(tty);
+	if (tty->link)
+		n_tty_packet_mode_flush(tty);
+
 	kfree(ldata->read_buf);
 	kfree(ldata->echo_buf);
 	kfree(ldata);
@@ -1645,12 +1640,14 @@ static int n_tty_open(struct tty_struct *tty)
 		goto err_free_bufs;
 
 	tty->disc_data = ldata;
-	reset_buffer_flags(tty);
-	tty_unthrottle(tty);
+	reset_buffer_flags(tty->disc_data);
 	ldata->column = 0;
-	n_tty_set_termios(tty, NULL);
 	tty->minimum_to_wake = 1;
 	tty->closing = 0;
+	/* indicate buffer work may resume */
+	clear_bit(TTY_LDISC_HALTED, &tty->flags);
+	n_tty_set_termios(tty, NULL);
+	tty_unthrottle(tty);
 
 	return 0;
 err_free_bufs:
@@ -1740,10 +1737,9 @@ extern ssize_t redirected_tty_write(struct file *, const char __user *,
  *	and if appropriate send any needed signals and return a negative
  *	error code if action should be taken.
  *
- *	FIXME:
- *	Locking: None - redirected write test is safe, testing
- *	current->signal should possibly lock current->sighand
- *	pgrp locking ?
+ *	Locking: redirected write test is safe
+ *		 current->signal->tty chec