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Commit 7ca0ff9a authored by Alan Cox's avatar Alan Cox Committed by Live-CD User
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tty: Add a full port_close function 



Now we are extracting out methods for shutdown and the like we can add a
proper tty_port_close method that knows all the innards of the tty closing
process and hides the lot from the caller.

At some point in the future this will be paired with a similar open()
helper and the drivers can stick to hardware management.

Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
Cc: stable <stable@kernel.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 24d481ec

drivers/char/tty_port.c

+27 −2
Original line number Diff line number Diff line
@@ -96,6 +96,14 @@ void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty) 
}

EXPORT_SYMBOL(tty_port_tty_set);



static void tty_port_shutdown(struct tty_port *port)

{

	if (port->ops->shutdown &&

		test_and_clear_bit(ASYNC_INITIALIZED, &port->flags))

			port->ops->shutdown(port);



}



/**

 *	tty_port_hangup		-	hangup helper

 *	@port: tty port
@@ -116,6 +124,7 @@ void tty_port_hangup(struct tty_port *port) 
	port->tty = NULL;

	spin_unlock_irqrestore(&port->lock, flags);

	wake_up_interruptible(&port->open_wait);

	tty_port_shutdown(port);

}

EXPORT_SYMBOL(tty_port_hangup);
@@ -296,15 +305,17 @@ int tty_port_close_start(struct tty_port *port, struct tty_struct *tty, struct f 


	if (port->count) {

		spin_unlock_irqrestore(&port->lock, flags);

		if (port->ops->drop)

			port->ops->drop(port);

		return 0;

	}

	port->flags |= ASYNC_CLOSING;

	set_bit(ASYNC_CLOSING, &port->flags);

	tty->closing = 1;

	spin_unlock_irqrestore(&port->lock, flags);

	/* Don't block on a stalled port, just pull the chain */

	if (tty->flow_stopped)

		tty_driver_flush_buffer(tty);

	if (port->flags & ASYNC_INITIALIZED &&

	if (test_bit(ASYNCB_INITIALIZED, &port->flags) &&

			port->closing_wait != ASYNC_CLOSING_WAIT_NONE)

		tty_wait_until_sent(tty, port->closing_wait);

	if (port->drain_delay) {
@@ -318,6 +329,9 @@ int tty_port_close_start(struct tty_port *port, struct tty_struct *tty, struct f 
			timeout = 2 * HZ;

		schedule_timeout_interruptible(timeout);

	}

	/* Don't call port->drop for the last reference. Callers will want

	   to drop the last active reference in ->shutdown() or the tty

	   shutdown path */

	return 1;

}

EXPORT_SYMBOL(tty_port_close_start);
@@ -348,3 +362,14 @@ void tty_port_close_end(struct tty_port *port, struct tty_struct *tty) 
	spin_unlock_irqrestore(&port->lock, flags);

}

EXPORT_SYMBOL(tty_port_close_end);



void tty_port_close(struct tty_port *port, struct tty_struct *tty,

							struct file *filp)

{

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

		return;

	tty_port_shutdown(port);

	tty_port_close_end(port, tty);

	tty_port_tty_set(port, NULL);

}

EXPORT_SYMBOL(tty_port_close);

include/linux/tty.h

+7 −1
Original line number Diff line number Diff line
@@ -187,7 +187,12 @@ struct tty_port; 
struct tty_port_operations {

	/* Return 1 if the carrier is raised */

	int (*carrier_raised)(struct tty_port *port);

	/* Control the DTR line */

	void (*dtr_rts)(struct tty_port *port, int raise);

	/* Called when the last close completes or a hangup finishes

	   IFF the port was initialized. Do not use to free resources */

	void (*shutdown)(struct tty_port *port);

	void (*drop)(struct tty_port *port);

};

	

struct tty_port {
@@ -459,7 +464,8 @@ extern int tty_port_block_til_ready(struct tty_port *port, 
extern int tty_port_close_start(struct tty_port *port,

				struct tty_struct *tty, struct file *filp);

extern void tty_port_close_end(struct tty_port *port, struct tty_struct *tty);



extern void tty_port_close(struct tty_port *port,

				struct tty_struct *tty, struct file *filp);

extern int tty_register_ldisc(int disc, struct tty_ldisc_ops *new_ldisc);

extern int tty_unregister_ldisc(int disc);

extern int tty_set_ldisc(struct tty_struct *tty, int ldisc);