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Commit 61cd8a21 authored by Alan Cox's avatar Alan Cox Committed by Greg Kroah-Hartman
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serial: Change the wait for carrier locking 



We want to push the lock/unlock into the helper functions so that we
can prepare to move to using the tty_port helper. The expansion initially
comes out a bit ugly but its worth the temporary expansion IMHO just so
we can produce a nice testable series of changes.

Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 8ce73264

drivers/serial/serial_core.c

+35 −9
Original line number Diff line number Diff line
@@ -1272,6 +1272,7 @@ static void uart_close(struct tty_struct *tty, struct file *filp) 
	struct uart_state *state = tty->driver_data;

	struct tty_port *port;

	struct uart_port *uport;

	unsigned long flags;



	BUG_ON(!kernel_locked());
@@ -1284,9 +1285,12 @@ static void uart_close(struct tty_struct *tty, struct file *filp) 
	pr_debug("uart_close(%d) called\n", uport->line);



	mutex_lock(&port->mutex);

	spin_lock_irqsave(&port->lock, flags);



	if (tty_hung_up_p(filp))

	if (tty_hung_up_p(filp)) {

		spin_unlock_irqrestore(&port->lock, flags);

		goto done;

	}



	if ((tty->count == 1) && (port->count != 1)) {

		/*
@@ -1305,8 +1309,10 @@ static void uart_close(struct tty_struct *tty, struct file *filp) 
		       tty->name, port->count);

		port->count = 0;

	}

	if (port->count)

	if (port->count) {

		spin_unlock_irqrestore(&port->lock, flags);

		goto done;

	}



	/*

	 * Now we wait for the transmit buffer to clear; and we notify
@@ -1314,6 +1320,7 @@ static void uart_close(struct tty_struct *tty, struct file *filp) 
	 * setting tty->closing.

	 */

	tty->closing = 1;

	spin_unlock_irqrestore(&port->lock, flags);



	if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)

		tty_wait_until_sent(tty, msecs_to_jiffies(port->closing_wait));
@@ -1340,20 +1347,26 @@ static void uart_close(struct tty_struct *tty, struct file *filp) 


	tty_ldisc_flush(tty);



	tty->closing = 0;

	tty_port_tty_set(port, NULL);

	spin_lock_irqsave(&port->lock, flags);

	tty->closing = 0;



	if (port->blocked_open) {

		spin_unlock_irqrestore(&port->lock, flags);

		if (port->close_delay)

			msleep_interruptible(port->close_delay);

		spin_lock_irqsave(&port->lock, flags);

	} else if (!uart_console(uport)) {

		spin_unlock_irqrestore(&port->lock, flags);

		uart_change_pm(state, 3);

		spin_lock_irqsave(&port->lock, flags);

	}



	/*

	 * Wake up anyone trying to open this port.

	 */

	clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);

	spin_unlock_irqrestore(&port->lock, flags);

	wake_up_interruptible(&port->open_wait);



done:
@@ -1429,6 +1442,7 @@ static void uart_hangup(struct tty_struct *tty) 
{

	struct uart_state *state = tty->driver_data;

	struct tty_port *port = &state->port;

	unsigned long flags;



	BUG_ON(!kernel_locked());

	pr_debug("uart_hangup(%d)\n", state->uart_port->line);
@@ -1437,8 +1451,10 @@ static void uart_hangup(struct tty_struct *tty) 
	if (port->flags & ASYNC_NORMAL_ACTIVE) {

		uart_flush_buffer(tty);

		uart_shutdown(tty, state);

		spin_lock_irqsave(&port->lock, flags);

		port->count = 0;

		clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);

		spin_unlock_irqrestore(&port->lock, flags);

		tty_port_tty_set(port, NULL);

		wake_up_interruptible(&port->open_wait);

		wake_up_interruptible(&port->delta_msr_wait);
@@ -1496,9 +1512,13 @@ uart_block_til_ready(struct file *filp, struct uart_state *state) 
	struct uart_port *uport = state->uart_port;

	struct tty_port *port = &state->port;

	unsigned int mctrl;

	unsigned long flags;



	port->blocked_open++;

	spin_lock_irqsave(&port->lock, flags);

	if (!tty_hung_up_p(filp))

		port->count--;

	port->blocked_open++;

	spin_unlock_irqrestore(&port->lock, flags);



	add_wait_queue(&port->open_wait, &wait);

	while (1) {
@@ -1535,23 +1555,26 @@ uart_block_til_ready(struct file *filp, struct uart_state *state) 
		 * not set RTS here - we want to make sure we catch

		 * the data from the modem.

		 */

		if (port->tty->termios->c_cflag & CBAUD)

		if (port->tty->termios->c_cflag & CBAUD) {

			mutex_lock(&port->mutex);

			uart_set_mctrl(uport, TIOCM_DTR);

			mutex_unlock(&port->mutex);

		}



		/*

		 * and wait for the carrier to indicate that the

		 * modem is ready for us.

		 */

		mutex_lock(&port->mutex);

		spin_lock_irq(&uport->lock);

		uport->ops->enable_ms(uport);

		mctrl = uport->ops->get_mctrl(uport);

		spin_unlock_irq(&uport->lock);

		mutex_unlock(&port->mutex);

		if (mctrl & TIOCM_CAR)

			break;



		mutex_unlock(&port->mutex);

		schedule();

		mutex_lock(&port->mutex);



		if (signal_pending(current))

			break;
@@ -1559,8 +1582,11 @@ uart_block_til_ready(struct file *filp, struct uart_state *state) 
	set_current_state(TASK_RUNNING);

	remove_wait_queue(&port->open_wait, &wait);



	spin_lock_irqsave(&port->lock, flags);

	if (!tty_hung_up_p(filp))

		port->count++;

	port->blocked_open--;

	spin_unlock_irqrestore(&port->lock, flags);



	if (signal_pending(current))

		return -ERESTARTSYS;
@@ -1677,9 +1703,9 @@ static int uart_open(struct tty_struct *tty, struct file *filp) 
	/*

	 * If we succeeded, wait until the port is ready.

	 */

	mutex_unlock(&port->mutex);

	if (retval == 0)

		retval = uart_block_til_ready(filp, state);

	mutex_unlock(&port->mutex);



	/*

	 * If this is the first open to succeed, adjust things to suit.