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Commit 510a3049 authored by Alan Cox's avatar Alan Cox Committed by Linus Torvalds
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tty: relock generic_serial 



Switch generic_serial to do port count locking via the tty_port structure
ready for moving to a common port wait routine. Keep the old driver lock for
internal calling so we don't risk messing up the drivers below until we
are ready.

Still needs kref conversions

Signed-off-by: default avatarAlan Cox <alan@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3e61696b

drivers/char/generic_serial.c

+24 −13
Original line number Diff line number Diff line
@@ -377,6 +377,7 @@ static void gs_shutdown_port (struct gs_port *port) 
void gs_hangup(struct tty_struct *tty)

{

	struct gs_port *port;

	unsigned long flags;



	func_enter ();
@@ -386,9 +387,11 @@ void gs_hangup(struct tty_struct *tty) 
		return;



	gs_shutdown_port (port);

	spin_lock_irqsave(&port->port.lock, flags);

	port->port.flags &= ~(ASYNC_NORMAL_ACTIVE|GS_ACTIVE);

	port->port.tty = NULL;

	port->port.count = 0;

	spin_unlock_irqrestore(&port->port.lock, flags);



	wake_up_interruptible(&port->port.open_wait);

	func_exit ();
@@ -454,12 +457,12 @@ int gs_block_til_ready(void *port_, struct file * filp) 
	add_wait_queue(&port->open_wait, &wait);



	gs_dprintk (GS_DEBUG_BTR, "after add waitq.\n"); 

	spin_lock_irqsave(&gp->driver_lock, flags);

	spin_lock_irqsave(&port->lock, flags);

	if (!tty_hung_up_p(filp)) {

		port->count--;

	}

	spin_unlock_irqrestore(&gp->driver_lock, flags);

	port->blocked_open++;

	spin_unlock_irqrestore(&port->lock, flags);

	while (1) {

		CD = tty_port_carrier_raised(port);

		gs_dprintk (GS_DEBUG_BTR, "CD is now %d.\n", CD);
@@ -487,16 +490,17 @@ int gs_block_til_ready(void *port_, struct file * filp) 
		    port->blocked_open);

	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--;

	if (retval)

		return retval;



	if (retval == 0)

        	port->flags |= ASYNC_NORMAL_ACTIVE;

	spin_unlock_irqrestore(&port->lock, flags);

	func_exit ();

	return 0;

	return retval;

}
@@ -517,10 +521,10 @@ void gs_close(struct tty_struct * tty, struct file * filp) 
		port->port.tty = tty;

	}



	spin_lock_irqsave(&port->driver_lock, flags);

	spin_lock_irqsave(&port->port.lock, flags);



	if (tty_hung_up_p(filp)) {

		spin_unlock_irqrestore(&port->driver_lock, flags);

		spin_unlock_irqrestore(&port->port.lock, flags);

		if (port->rd->hungup)

			port->rd->hungup (port);

		func_exit ();
@@ -539,7 +543,7 @@ void gs_close(struct tty_struct * tty, struct file * filp) 


	if (port->port.count) {

		gs_dprintk(GS_DEBUG_CLOSE, "gs_close port %p: count: %d\n", port, port->port.count);

		spin_unlock_irqrestore(&port->driver_lock, flags);

		spin_unlock_irqrestore(&port->port.lock, flags);

		func_exit ();

		return;

	}
@@ -560,8 +564,10 @@ void gs_close(struct tty_struct * tty, struct file * filp) 
	 * line status register.

	 */



	spin_lock_irqsave(&port->driver_lock, flags);

	port->rd->disable_rx_interrupts (port);

	spin_unlock_irqrestore(&port->driver_lock, flags);

	spin_unlock_irqrestore(&port->port.lock, flags);



	/* close has no way of returning "EINTR", so discard return value */

	if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)
@@ -574,20 +580,25 @@ void gs_close(struct tty_struct * tty, struct file * filp) 
	tty_ldisc_flush(tty);

	tty->closing = 0;



	spin_lock_irqsave(&port->driver_lock, flags);

	port->event = 0;

	port->rd->close (port);

	port->rd->shutdown_port (port);

	spin_unlock_irqrestore(&port->driver_lock, flags);



	spin_lock_irqsave(&port->port.lock, flags);

	port->port.tty = NULL;



	if (port->port.blocked_open) {

		if (port->close_delay) {

			spin_unlock_irqrestore(&port->driver_lock, flags);

			spin_unlock_irqrestore(&port->port.lock, flags);

			msleep_interruptible(jiffies_to_msecs(port->close_delay));

			spin_lock_irqsave(&port->driver_lock, flags);

			spin_lock_irqsave(&port->port.lock, flags);

		}

		wake_up_interruptible(&port->port.open_wait);

	}

	port->port.flags &= ~(ASYNC_NORMAL_ACTIVE|ASYNC_CLOSING | ASYNC_INITIALIZED);

	spin_unlock_irqrestore(&port->port.lock, flags);

	wake_up_interruptible(&port->port.close_wait);



	func_exit ();