1 files changed, 109 insertions, 86 deletions

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 2c7230aaefd..fbf6c5ad222 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -50,16 +50,11 @@ static struct lock_class_key port_lock_key;
 
 #define HIGH_BITS_OFFSET	((sizeof(long)-sizeof(int))*8)
 
-#ifdef CONFIG_SERIAL_CORE_CONSOLE
-#define uart_console(port)	((port)->cons && (port)->cons->index == (port)->line)
-#else
-#define uart_console(port)	(0)
-#endif
-
 static void uart_change_speed(struct tty_struct *tty, struct uart_state *state,
 					struct ktermios *old_termios);
 static void uart_wait_until_sent(struct tty_struct *tty, int timeout);
-static void uart_change_pm(struct uart_state *state, int pm_state);
+static void uart_change_pm(struct uart_state *state,
+			   enum uart_pm_state pm_state);
 
 static void uart_port_shutdown(struct tty_port *port);
 
@@ -94,8 +89,7 @@ static void __uart_start(struct tty_struct *tty)
 	struct uart_state *state = tty->driver_data;
 	struct uart_port *port = state->uart_port;
 
-	if (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
-	    !tty->stopped && !tty->hw_stopped)
+	if (!tty->stopped && !tty->hw_stopped)
 		port->ops->start_tx(port);
 }
 
@@ -143,6 +137,11 @@ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
 		return 1;
 
 	/*
+	 * Make sure the device is in D0 state.
+	 */
+	uart_change_pm(state, UART_PM_STATE_ON);
+
+	/*
 	 * Initialise and allocate the transmit and temporary
 	 * buffer.
 	 */
@@ -175,8 +174,12 @@ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
 			if (tty->termios.c_cflag & CBAUD)
 				uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
 		}
-
-		if (tty_port_cts_enabled(port)) {
+		/*
+		 * if hw support flow control without software intervention,
+		 * then skip the below check
+		 */
+		if (tty_port_cts_enabled(port) &&
+		    !(uport->flags & UPF_HARD_FLOW)) {
 			spin_lock_irq(&uport->lock);
 			if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
 				tty->hw_stopped = 1;
@@ -831,25 +834,29 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
 		 * If we fail to request resources for the
 		 * new port, try to restore the old settings.
 		 */
-		if (retval && old_type != PORT_UNKNOWN) {
+		if (retval) {
 			uport->iobase = old_iobase;
 			uport->type = old_type;
 			uport->hub6 = old_hub6;
 			uport->iotype = old_iotype;
 			uport->regshift = old_shift;
 			uport->mapbase = old_mapbase;
-			retval = uport->ops->request_port(uport);
-			/*
-			 * If we failed to restore the old settings,
-			 * we fail like this.
-			 */
-			if (retval)
-				uport->type = PORT_UNKNOWN;
 
-			/*
-			 * We failed anyway.
-			 */
-			retval = -EBUSY;
+			if (old_type != PORT_UNKNOWN) {
+				retval = uport->ops->request_port(uport);
+				/*
+				 * If we failed to restore the old settings,
+				 * we fail like this.
+				 */
+				if (retval)
+					uport->type = PORT_UNKNOWN;
+
+				/*
+				 * We failed anyway.
+				 */
+				retval = -EBUSY;
+			}
+
 			/* Added to return the correct error -Ram Gupta */
 			goto exit;
 		}
@@ -866,9 +873,7 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
 	port->closing_wait    = closing_wait;
 	if (new_info->xmit_fifo_size)
 		uport->fifosize = new_info->xmit_fifo_size;
-	if (port->tty)
-		port->tty->low_latency =
-			(uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
+	port->low_latency = (uport->flags & UPF_LOW_LATENCY) ? 1 : 0;
 
  check_and_exit:
 	retval = 0;
@@ -1308,9 +1313,10 @@ static void uart_set_termios(struct tty_struct *tty,
 }
 
 /*
- * In 2.4.5, calls to this will be serialized via the BKL in
- *  linux/drivers/char/tty_io.c:tty_release()
- *  linux/drivers/char/tty_io.c:do_tty_handup()
+ * Calls to uart_close() are serialised via the tty_lock in
+ *   drivers/tty/tty_io.c:tty_release()
+ *   drivers/tty/tty_io.c:do_tty_hangup()
+ * This runs from a workqueue and can sleep for a _short_ time only.
  */
 static void uart_close(struct tty_struct *tty, struct file *filp)
 {
@@ -1325,9 +1331,9 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
 	uport = state->uart_port;
 	port = &state->port;
 
-	pr_debug("uart_close(%d) called\n", uport->line);
+	pr_debug("uart_close(%d) called\n", uport ? uport->line : -1);
 
-	if (tty_port_close_start(port, tty, filp) == 0)
+	if (!port->count || tty_port_close_start(port, tty, filp) == 0)
 		return;
 
 	/*
@@ -1365,7 +1371,7 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
 		spin_lock_irqsave(&port->lock, flags);
 	} else if (!uart_console(uport)) {
 		spin_unlock_irqrestore(&port->lock, flags);
-		uart_change_pm(state, 3);
+		uart_change_pm(state, UART_PM_STATE_OFF);
 		spin_lock_irqsave(&port->lock, flags);
 	}
 
@@ -1437,10 +1443,9 @@ static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
 }
 
 /*
- * This is called with the BKL held in
- *  linux/drivers/char/tty_io.c:do_tty_hangup()
- * We're called from the eventd thread, so we can sleep for
- * a _short_ time only.
+ * Calls to uart_hangup() are serialised by the tty_lock in
+ *   drivers/tty/tty_io.c:do_tty_hangup()
+ * This runs from a workqueue and can sleep for a _short_ time only.
  */
 static void uart_hangup(struct tty_struct *tty)
 {
@@ -1459,6 +1464,8 @@ static void uart_hangup(struct tty_struct *tty)
 		clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
 		spin_unlock_irqrestore(&port->lock, flags);
 		tty_port_tty_set(port, NULL);
+		if (!uart_console(state->uart_port))
+			uart_change_pm(state, UART_PM_STATE_OFF);
 		wake_up_interruptible(&port->open_wait);
 		wake_up_interruptible(&port->delta_msr_wait);
 	}
@@ -1521,8 +1528,8 @@ static void uart_dtr_rts(struct tty_port *port, int onoff)
 }
 
 /*
- * calls to uart_open are serialised by the BKL in
- *   fs/char_dev.c:chrdev_open()
+ * Calls to uart_open are serialised by the tty_lock in
+ *   drivers/tty/tty_io.c:tty_open()
  * Note that if this fails, then uart_close() _will_ be called.
  *
  * In time, we want to scrap the "opening nonpresent ports"
@@ -1564,7 +1571,8 @@ static int uart_open(struct tty_struct *tty, struct file *filp)
 	 */
 	tty->driver_data = state;
 	state->uart_port->state = state;
-	tty->low_latency = (state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
+	state->port.low_latency =
+		(state->uart_port->flags & UPF_LOW_LATENCY) ? 1 : 0;
 	tty_port_tty_set(port, tty);
 
 	/*
@@ -1576,12 +1584,6 @@ static int uart_open(struct tty_struct *tty, struct file *filp)
 	}
 
 	/*
-	 * Make sure the device is in D0 state.
-	 */
-	if (port->count == 1)
-		uart_change_pm(state, 0);
-
-	/*
 	 * Start up the serial port.
 	 */
 	retval = uart_startup(tty, state, 0);
@@ -1620,7 +1622,7 @@ static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
 {
 	struct uart_state *state = drv->state + i;
 	struct tty_port *port = &state->port;
-	int pm_state;
+	enum uart_pm_state pm_state;
 	struct uart_port *uport = state->uart_port;
 	char stat_buf[32];
 	unsigned int status;
@@ -1645,12 +1647,12 @@ static void uart_line_info(struct seq_file *m, struct uart_driver *drv, int i)
 	if (capable(CAP_SYS_ADMIN)) {
 		mutex_lock(&port->mutex);
 		pm_state = state->pm_state;
-		if (pm_state)
-			uart_change_pm(state, 0);
+		if (pm_state != UART_PM_STATE_ON)
+			uart_change_pm(state, UART_PM_STATE_ON);
 		spin_lock_irq(&uport->lock);
 		status = uport->ops->get_mctrl(uport);
 		spin_unlock_irq(&uport->lock);
-		if (pm_state)
+		if (pm_state != UART_PM_STATE_ON)
 			uart_change_pm(state, pm_state);
 		mutex_unlock(&port->mutex);
 
@@ -1711,7 +1713,7 @@ static int uart_proc_show(struct seq_file *m, void *v)
 
 static int uart_proc_open(struct inode *inode, struct file *file)
 {
-	return single_open(file, uart_proc_show, PDE(inode)->data);
+	return single_open(file, uart_proc_show, PDE_DATA(inode));
 }
 
 static const struct file_operations uart_proc_fops = {
@@ -1768,7 +1770,7 @@ uart_get_console(struct uart_port *ports, int nr, struct console *co)
 }
 
 /**
- *	uart_parse_options - Parse serial port baud/parity/bits/flow contro.
+ *	uart_parse_options - Parse serial port baud/parity/bits/flow control.
  *	@options: pointer to option string
  *	@baud: pointer to an 'int' variable for the baud rate.
  *	@parity: pointer to an 'int' variable for the parity.
@@ -1836,9 +1838,13 @@ uart_set_options(struct uart_port *port, struct console *co,
 	/*
 	 * Ensure that the serial console lock is initialised
 	 * early.
+	 * If this port is a console, then the spinlock is already
+	 * initialised.
 	 */
-	spin_lock_init(&port->lock);
-	lockdep_set_class(&port->lock, &port_lock_key);
+	if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
+		spin_lock_init(&port->lock);
+		lockdep_set_class(&port->lock, &port_lock_key);
+	}
 
 	memset(&termios, 0, sizeof(struct ktermios));
 
@@ -1897,7 +1903,8 @@ EXPORT_SYMBOL_GPL(uart_set_options);
  *
  * Locking: port->mutex has to be held
  */
-static void uart_change_pm(struct uart_state *state, int pm_state)
+static void uart_change_pm(struct uart_state *state,
+			   enum uart_pm_state pm_state)
 {
 	struct uart_port *port = state->uart_port;
 
@@ -1940,6 +1947,8 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
 		mutex_unlock(&port->mutex);
 		return 0;
 	}
+	put_device(tty_dev);
+
 	if (console_suspend_enabled || !uart_console(uport))
 		uport->suspended = 1;
 
@@ -1982,7 +1991,7 @@ int uart_suspend_port(struct uart_driver *drv, struct uart_port *uport)
 		console_stop(uport->cons);
 
 	if (console_suspend_enabled || !uart_console(uport))
-		uart_change_pm(state, 3);
+		uart_change_pm(state, UART_PM_STATE_OFF);
 
 	mutex_unlock(&port->mutex);
 
@@ -2005,9 +2014,11 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
 			disable_irq_wake(uport->irq);
 			uport->irq_wake = 0;
 		}
+		put_device(tty_dev);
 		mutex_unlock(&port->mutex);
 		return 0;
 	}
+	put_device(tty_dev);
 	uport->suspended = 0;
 
 	/*
@@ -2027,7 +2038,7 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
 			termios = port->tty->termios;
 
 		if (console_suspend_enabled)
-			uart_change_pm(state, 0);
+			uart_change_pm(state, UART_PM_STATE_ON);
 		uport->ops->set_termios(uport, &termios, NULL);
 		if (console_suspend_enabled)
 			console_start(uport->cons);
@@ -2037,7 +2048,7 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *uport)
 		const struct uart_ops *ops = uport->ops;
 		int ret;
 
-		uart_change_pm(state, 0);
+		uart_change_pm(state, UART_PM_STATE_ON);
 		spin_lock_irq(&uport->lock);
 		ops->set_mctrl(uport, 0);
 		spin_unlock_irq(&uport->lock);
@@ -2096,12 +2107,12 @@ uart_report_port(struct uart_driver *drv, struct uart_port *port)
 		break;
 	}
 
-	printk(KERN_INFO "%s%s%s%d at %s (irq = %d) is a %s\n",
+	printk(KERN_INFO "%s%s%s%d at %s (irq = %d, base_baud = %d) is a %s\n",
 	       port->dev ? dev_name(port->dev) : "",
 	       port->dev ? ": " : "",
 	       drv->dev_name,
 	       drv->tty_driver->name_base + port->line,
-	       address, port->irq, uart_type(port));
+	       address, port->irq, port->uartclk / 16, uart_type(port));
 }
 
 static void
@@ -2137,7 +2148,7 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 		uart_report_port(drv, port);
 
 		/* Power up port for set_mctrl() */
-		uart_change_pm(state, 0);
+		uart_change_pm(state, UART_PM_STATE_ON);
 
 		/*
 		 * Ensure that the modem control lines are de-activated.
@@ -2161,7 +2172,7 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
 		 * console if we have one.
 		 */
 		if (!uart_console(port))
-			uart_change_pm(state, 3);
+			uart_change_pm(state, UART_PM_STATE_OFF);
 	}
 }
 
@@ -2232,6 +2243,9 @@ static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
 		return;
 
 	port = state->uart_port;
+
+	if (ch == '\n')
+		port->ops->poll_put_char(port, '\r');
 	port->ops->poll_put_char(port, ch);
 }
 #endif
@@ -2588,7 +2602,7 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
 	}
 
 	state->uart_port = uport;
-	state->pm_state = -1;
+	state->pm_state = UART_PM_STATE_UNDEFINED;
 
 	uport->cons = drv->cons;
 	uport->state = state;
@@ -2606,7 +2620,7 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
 
 	/*
 	 * Register the port whether it's detected or not.  This allows
-	 * setserial to be used to alter this ports parameters.
+	 * setserial to be used to alter this port's parameters.
 	 */
 	tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
 			uport->line, uport->dev, port, tty_dev_attr_groups);
@@ -2642,6 +2656,8 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
 {
 	struct uart_state *state = drv->state + uport->line;
 	struct tty_port *port = &state->port;
+	struct tty_struct *tty;
+	int ret = 0;
 
 	BUG_ON(in_interrupt());
 
@@ -2656,6 +2672,11 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
 	 * succeeding while we shut down the port.
 	 */
 	mutex_lock(&port->mutex);
+	if (!state->uart_port) {
+		mutex_unlock(&port->mutex);
+		ret = -EINVAL;
+		goto out;
+	}
 	uport->flags |= UPF_DEAD;
 	mutex_unlock(&port->mutex);
 
@@ -2664,8 +2685,17 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
 	 */
 	tty_unregister_device(drv->tty_driver, uport->line);
 
-	if (port->tty)
+	tty = tty_port_tty_get(port);
+	if (tty) {
 		tty_vhangup(port->tty);
+		tty_kref_put(tty);
+	}
+
+	/*
+	 * If the port is used as a console, unregister it
+	 */
+	if (uart_console(uport))
+		unregister_console(uport->cons);
 
 	/*
 	 * Free the port IO and memory resources, if any.
@@ -2679,9 +2709,10 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
 	uport->type = PORT_UNKNOWN;
 
 	state->uart_port = NULL;
+out:
 	mutex_unlock(&port_mutex);
 
-	return 0;
+	return ret;
 }
 
 /*
@@ -2715,22 +2746,17 @@ EXPORT_SYMBOL(uart_match_port);
  */
 void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
 {
-	struct uart_state *state = uport->state;
-	struct tty_port *port = &state->port;
-	struct tty_ldisc *ld = NULL;
-	struct pps_event_time ts;
+	struct tty_port *port = &uport->state->port;
 	struct tty_struct *tty = port->tty;
+	struct tty_ldisc *ld = tty ? tty_ldisc_ref(tty) : NULL;
 
-	if (tty)
-	        ld = tty_ldisc_ref(tty);
-	if (ld && ld->ops->dcd_change)
-		pps_get_ts(&ts);
+	if (ld) {
+		if (ld->ops->dcd_change)
+			ld->ops->dcd_change(tty, status);
+		tty_ldisc_deref(ld);
+	}
 
 	uport->icount.dcd++;
-#ifdef CONFIG_HARD_PPS
-	if ((uport->flags & UPF_HARDPPS_CD) && status)
-		hardpps();
-#endif
 
 	if (port->flags & ASYNC_CHECK_CD) {
 		if (status)
@@ -2738,11 +2764,6 @@ void uart_handle_dcd_change(struct uart_port *uport, unsigned int status)
 		else if (tty)
 			tty_hangup(tty);
 	}
-
-	if (ld && ld->ops->dcd_change)
-		ld->ops->dcd_change(tty, status, &ts);
-	if (ld)
-		tty_ldisc_deref(ld);
 }
 EXPORT_SYMBOL_GPL(uart_handle_dcd_change);
 
@@ -2758,7 +2779,9 @@ void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
 
 	uport->icount.cts++;
 
-	if (tty_port_cts_enabled(port)) {
+	/* skip below code if the hw flow control is supported */
+	if (tty_port_cts_enabled(port) &&
+	    !(uport->flags & UPF_HARD_FLOW)) {
 		if (tty->hw_stopped) {
 			if (status) {
 				tty->hw_stopped = 0;
@@ -2790,10 +2813,10 @@ EXPORT_SYMBOL_GPL(uart_handle_cts_change);
 void uart_insert_char(struct uart_port *port, unsigned int status,
 		 unsigned int overrun, unsigned int ch, unsigned int flag)
 {
-	struct tty_struct *tty = port->state->port.tty;
+	struct tty_port *tport = &port->state->port;
 
 	if ((status & port->ignore_status_mask & ~overrun) == 0)
-		if (tty_insert_flip_char(tty, ch, flag) == 0)
+		if (tty_insert_flip_char(tport, ch, flag) == 0)
 			++port->icount.buf_overrun;
 
 	/*
@@ -2801,7 +2824,7 @@ void uart_insert_char(struct uart_port *port, unsigned int status,
 	 * it doesn't affect the current character.
 	 */
 	if (status & ~port->ignore_status_mask & overrun)
-		if (tty_insert_flip_char(tty, 0, TTY_OVERRUN) == 0)
+		if (tty_insert_flip_char(tport, 0, TTY_OVERRUN) == 0)
 			++port->icount.buf_overrun;
 }
 EXPORT_SYMBOL_GPL(uart_insert_char);