Commit 761ed4a9 authored by Rob Herring's avatar Rob Herring Committed by Greg Kroah-Hartman
Browse files

tty: serial_core: convert uart_close to use tty_port_close 



tty_port_close handles much of the common parts of tty close. Convert
uart_close to use it and move the serial_core specific parts into
tty_port.shutdown function. This will be needed to use tty_port functions
directly from in kernel clients.

This change causes ops->stop_rx() to be called after uart_wait_until_sent()
is called which I think should be fine. Otherwise, the sequence of the
close should be the same.

Cc: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: default avatarRob Herring <robh@kernel.org>
Acked-by: default avatarAlan Cox <alan@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent b3b57646

drivers/tty/serial/serial_core.c

+19 −37
Original line number Diff line number Diff line
@@ -1461,7 +1461,6 @@ 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;



	if (!state) {

		struct uart_driver *drv = tty->driver->driver_state;
@@ -1477,56 +1476,36 @@ static void uart_close(struct tty_struct *tty, struct file *filp) 
	port = &state->port;

	pr_debug("uart_close(%d) called\n", tty->index);



	if (tty_port_close_start(port, tty, filp) == 0)

		return;

	tty_port_close(tty->port, tty, filp);

}



	mutex_lock(&port->mutex);

	uport = uart_port_check(state);

static void uart_tty_port_shutdown(struct tty_port *port)

{

	struct uart_state *state = container_of(port, struct uart_state, port);

	struct uart_port *uport = uart_port_check(state);



	spin_lock_irq(&uport->lock);

	/*

	 * At this point, we stop accepting input.  To do this, we

	 * disable the receive line status interrupts.

	 */

	if (tty_port_initialized(port) &&

	    !WARN(!uport, "detached port still initialized!\n")) {

		spin_lock_irq(&uport->lock);

		uport->ops->stop_rx(uport);

		spin_unlock_irq(&uport->lock);

		/*

		 * Before we drop DTR, make sure the UART transmitter

		 * has completely drained; this is especially

		 * important if there is a transmit FIFO!

		 */

		uart_wait_until_sent(tty, uport->timeout);

	}

	WARN(!uport, "detached port still initialized!\n");



	uart_shutdown(tty, state);

	tty_port_tty_set(port, NULL);

	uport->ops->stop_rx(uport);



	spin_lock_irq(&port->lock);

	spin_unlock_irq(&uport->lock);



	if (port->blocked_open) {

		spin_unlock_irq(&port->lock);

		if (port->close_delay)

			msleep_interruptible(jiffies_to_msecs(port->close_delay));

		spin_lock_irq(&port->lock);

	} else if (uport && !uart_console(uport)) {

		spin_unlock_irq(&port->lock);

		uart_change_pm(state, UART_PM_STATE_OFF);

		spin_lock_irq(&port->lock);

	}

	spin_unlock_irq(&port->lock);

	tty_port_set_active(port, 0);

	uart_port_shutdown(port);



	/*

	 * Wake up anyone trying to open this port.

	 * It's possible for shutdown to be called after suspend if we get

	 * a DCD drop (hangup) at just the right time.  Clear suspended bit so

	 * we don't try to resume a port that has been shutdown.

	 */

	wake_up_interruptible(&port->open_wait);

	tty_port_set_suspended(port, 0);



	mutex_unlock(&port->mutex);

	uart_change_pm(state, UART_PM_STATE_OFF);



	tty_ldisc_flush(tty);

	tty->closing = 0;

}



static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
@@ -2446,6 +2425,7 @@ static const struct tty_port_operations uart_port_ops = { 
	.carrier_raised = uart_carrier_raised,

	.dtr_rts	= uart_dtr_rts,

	.activate	= uart_port_activate,

	.shutdown	= uart_tty_port_shutdown,

};



/**
@@ -2762,6 +2742,8 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport) 
	uport->cons = drv->cons;

	uport->minor = drv->tty_driver->minor_start + uport->line;



	port->console = uart_console(uport);



	/*

	 * If this port is a console, then the spinlock is already

	 * initialised.

CRA Git | Maintained and supported by SUSTech CRA and CCSE