Commit 3e61696b authored by Alan Cox's avatar Alan Cox Committed by Linus Torvalds
Browse files

isicom: redo locking to use tty port locks 



This helps set the basis for moving block_til_ready into common code. We also
introduce a tty_port_hangup helper as this will also be generally needed.

Signed-off-by: default avatarAlan Cox <alan@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 5d951fb4

drivers/char/isicom.c

+15 −20
Original line number Diff line number Diff line
@@ -841,7 +841,6 @@ static int isicom_carrier_raised(struct tty_port *port) 
static int block_til_ready(struct tty_struct *tty, struct file *filp,

	struct isi_port *ip)

{

	struct isi_board *card = ip->card;

	struct tty_port *port = &ip->port;

	int do_clocal = 0, retval;

	unsigned long flags;
@@ -876,11 +875,11 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp, 
	retval = 0;

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



	spin_lock_irqsave(&card->card_lock, flags);

	spin_lock_irqsave(&port->lock, flags);

	if (!tty_hung_up_p(filp))

		port->count--;

	port->blocked_open++;

	spin_unlock_irqrestore(&card->card_lock, flags);

	spin_unlock_irqrestore(&port->lock, flags);



	while (1) {

		tty_port_raise_dtr_rts(port);
@@ -905,14 +904,13 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp, 
	}

	set_current_state(TASK_RUNNING);

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

	spin_lock_irqsave(&card->card_lock, flags);

	spin_lock_irqsave(&port->lock, flags);

	if (!tty_hung_up_p(filp))

		port->count++;

	port->blocked_open--;

	spin_unlock_irqrestore(&card->card_lock, flags);

	if (retval)

		return retval;

	if (retval == 0)

		port->flags |= ASYNC_NORMAL_ACTIVE;

	spin_unlock_irqrestore(&port->lock, flags);

	return 0;

}
@@ -1034,9 +1032,9 @@ static void isicom_close(struct tty_struct *tty, struct file *filp) 


	pr_dbg("Close start!!!.\n");



	spin_lock_irqsave(&card->card_lock, flags);

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

	if (tty_hung_up_p(filp)) {

		spin_unlock_irqrestore(&card->card_lock, flags);

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

		return;

	}
@@ -1054,12 +1052,12 @@ static void isicom_close(struct tty_struct *tty, struct file *filp) 
	}



	if (port->port.count) {

		spin_unlock_irqrestore(&card->card_lock, flags);

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

		return;

	}

	port->port.flags |= ASYNC_CLOSING;

	tty->closing = 1;

	spin_unlock_irqrestore(&card->card_lock, flags);

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



	if (port->port.closing_wait != ASYNC_CLOSING_WAIT_NONE)

		tty_wait_until_sent(tty, port->port.closing_wait);
@@ -1076,22 +1074,22 @@ static void isicom_close(struct tty_struct *tty, struct file *filp) 
	isicom_flush_buffer(tty);

	tty_ldisc_flush(tty);



	spin_lock_irqsave(&card->card_lock, flags);

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

	tty->closing = 0;



	if (port->port.blocked_open) {

		spin_unlock_irqrestore(&card->card_lock, flags);

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

		if (port->port.close_delay) {

			pr_dbg("scheduling until time out.\n");

			msleep_interruptible(

				jiffies_to_msecs(port->port.close_delay));

		}

		spin_lock_irqsave(&card->card_lock, flags);

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

		wake_up_interruptible(&port->port.open_wait);

	}

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

	wake_up_interruptible(&port->port.close_wait);

	spin_unlock_irqrestore(&card->card_lock, flags);

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

}



/* write et all */
@@ -1430,10 +1428,7 @@ static void isicom_hangup(struct tty_struct *tty) 
	isicom_shutdown_port(port);

	spin_unlock_irqrestore(&port->card->card_lock, flags);



	port->port.count = 0;

	port->port.flags &= ~ASYNC_NORMAL_ACTIVE;

	tty_port_tty_set(&port->port, NULL);

	wake_up_interruptible(&port->port.open_wait);

	tty_port_hangup(&port->port);

}

drivers/char/synclinkmp.c

+14 −6
Original line number Diff line number Diff line
@@ -3331,6 +3331,17 @@ static int carrier_raised(struct tty_port *port) 
	return (info->serial_signals & SerialSignal_DCD) ? 1 : 0;

}



static void raise_dtr_rts(struct tty_port *port)

{

	SLMP_INFO *info = container_of(port, SLMP_INFO, port);

	unsigned long flags;



	spin_lock_irqsave(&info->lock,flags);

	info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;

 	set_signals(info);

	spin_unlock_irqrestore(&info->lock,flags);

}



/* Block the current process until the specified port is ready to open.

 */

static int block_til_ready(struct tty_struct *tty, struct file *filp,
@@ -3381,12 +3392,8 @@ static int block_til_ready(struct tty_struct *tty, struct file *filp, 
	port->blocked_open++;



	while (1) {

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

			spin_lock_irqsave(&info->lock,flags);

			info->serial_signals |= SerialSignal_RTS + SerialSignal_DTR;

		 	set_signals(info);

			spin_unlock_irqrestore(&info->lock,flags);

		}

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

			tty_port_raise_dtr_rts(port);



		set_current_state(TASK_INTERRUPTIBLE);
@@ -3793,6 +3800,7 @@ static void add_device(SLMP_INFO *info) 


static const struct tty_port_operations port_ops = {

	.carrier_raised = carrier_raised,

	.raise_dtr_rts = raise_dtr_rts,

};



/* Allocate and initialize a device instance structure

drivers/char/tty_port.c

+24 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 
#include <linux/tty.h>

#include <linux/tty_driver.h>

#include <linux/tty_flip.h>

#include <linux/serial.h>

#include <linux/timer.h>

#include <linux/string.h>

#include <linux/slab.h>
@@ -95,6 +96,29 @@ void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty) 
}

EXPORT_SYMBOL(tty_port_tty_set);



/**

 *	tty_port_hangup		-	hangup helper

 *	@port: tty port

 *

 *	Perform port level tty hangup flag and count changes. Drop the tty

 *	reference.

 */



void tty_port_hangup(struct tty_port *port)

{

	unsigned long flags;



	spin_lock_irqsave(&port->lock, flags);

	port->count = 0;

	port->flags &= ~ASYNC_NORMAL_ACTIVE;

	if (port->tty)

		tty_kref_put(port->tty);

	port->tty = NULL;

	spin_unlock_irqrestore(&port->lock, flags);

	wake_up_interruptible(&port->open_wait);

}

EXPORT_SYMBOL(tty_port_hangup);



/**

 *	tty_port_carrier_raised	-	carrier raised check

 *	@port: tty port

include/linux/tty.h

+1 −0
Original line number Diff line number Diff line
@@ -438,6 +438,7 @@ extern struct tty_struct *tty_port_tty_get(struct tty_port *port); 
extern void tty_port_tty_set(struct tty_port *port, struct tty_struct *tty);

extern int tty_port_carrier_raised(struct tty_port *port);

extern void tty_port_raise_dtr_rts(struct tty_port *port);

extern void tty_port_hangup(struct tty_port *port);



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

extern int tty_unregister_ldisc(int disc);

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