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Commit 6ed1dbae authored by Alan Cox's avatar Alan Cox Committed by Linus Torvalds
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tty: Make epca use the port helpers 



Now the locking is straight and the port kref usage is straight we can
replace lots of chunks of code with the standard port helpers

Signed-off-by: default avatarAlan Cox <alan@redhat.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 3969ffba

drivers/char/epca.c

+24 −148
Original line number Diff line number Diff line
@@ -432,58 +432,15 @@ static void pc_close(struct tty_struct *tty, struct file *filp) 
		return;

	port = &ch->port;



	spin_lock_irqsave(&port->lock, flags);

	if (tty_hung_up_p(filp)) {

		spin_unlock_irqrestore(&port->lock, flags);

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

		return;

	}

	if (port->count-- > 1)  {

		/* Begin channel is open more than once */

		/*

		 * Return without doing anything. Someone might still

		 * be using the channel.

		 */

		spin_unlock_irqrestore(&port->lock, flags);

		return;

	}

	/* Port open only once go ahead with shutdown & reset */

	WARN_ON(port->count < 0);



	/*

	 * Let the rest of the driver know the channel is being closed.

	 * This becomes important if an open is attempted before close

	 * is finished.

	 */

	port->flags |= ASYNC_CLOSING;

	tty->closing = 1;



	spin_unlock_irqrestore(&port->lock, flags);



	if (port->flags & ASYNC_INITIALIZED)  {

		/* Setup an event to indicate when the

		   transmit buffer empties */

		setup_empty_event(tty, ch);

		/* 30 seconds timeout */

		tty_wait_until_sent(tty, 3000);

	}

	pc_flush_buffer(tty);

	tty_ldisc_flush(tty);

	shutdown(ch, tty);



	spin_lock_irqsave(&port->lock, flags);

	tty->closing = 0;

	ch->event = 0;

	tty_port_close_end(port, tty);

	ch->event = 0;	/* FIXME: review ch->event locking */

	tty_port_tty_set(port, NULL);

	spin_unlock_irqrestore(&port->lock, flags);



	if (port->blocked_open) {

		if (ch->close_delay)

			msleep_interruptible(jiffies_to_msecs(ch->close_delay));

		wake_up_interruptible(&port->open_wait);

	}

	port->flags &= ~(ASYNC_NORMAL_ACTIVE | ASYNC_INITIALIZED |

							ASYNC_CLOSING);

	wake_up_interruptible(&port->close_wait);

}



static void shutdown(struct channel *ch, struct tty_struct *tty)
@@ -527,7 +484,6 @@ static void shutdown(struct channel *ch, struct tty_struct *tty) 
static void pc_hangup(struct tty_struct *tty)

{

	struct channel *ch;

	struct tty_port *port;



	/*

	 * verifyChannel returns the channel from the tty struct if it is
@@ -536,19 +492,13 @@ static void pc_hangup(struct tty_struct *tty) 
	ch = verifyChannel(tty);

	if (ch != NULL) {

		unsigned long flags;

		port = &ch->port;



		pc_flush_buffer(tty);

		tty_ldisc_flush(tty);

		shutdown(ch, tty);



		spin_lock_irqsave(&port->lock, flags);

		port->tty = NULL;

		ch->event = 0;	/* FIXME: review locking of ch->event */

		port->count = 0;

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

		spin_unlock_irqrestore(&port->lock, flags);

		wake_up_interruptible(&port->open_wait);

		tty_port_hangup(&ch->port);

	}

}
@@ -792,96 +742,16 @@ static void pc_flush_chars(struct tty_struct *tty) 
	}

}



static int block_til_ready(struct tty_struct *tty,

				struct file *filp, struct channel *ch)

static int epca_carrier_raised(struct tty_port *port)

{

	DECLARE_WAITQUEUE(wait, current);

	int retval, do_clocal = 0;

	unsigned long flags;

	struct tty_port *port = &ch->port;



	if (tty_hung_up_p(filp)) {

		if (port->flags & ASYNC_HUP_NOTIFY)

			retval = -EAGAIN;

		else

			retval = -ERESTARTSYS;

		return retval;

	}



	/*

	 * If the device is in the middle of being closed, then block until

	 * it's done, and then try again.

	 */

	if (port->flags & ASYNC_CLOSING) {

		interruptible_sleep_on(&port->close_wait);



		if (port->flags & ASYNC_HUP_NOTIFY)

			return -EAGAIN;

		else

			return -ERESTARTSYS;

	}



	if (filp->f_flags & O_NONBLOCK)  {

		/*

		 * If non-blocking mode is set, then make the check up front

		 * and then exit.

		 */

		port->flags |= ASYNC_NORMAL_ACTIVE;

	struct channel *ch = container_of(port, struct channel, port);

	if (ch->imodem & ch->dcd)

		return 1;

	return 0;

}

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

		do_clocal = 1;

	/* Block waiting for the carrier detect and the line to become free */



	retval = 0;

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



	spin_lock_irqsave(&port->lock, flags);

	/* We dec count so that pc_close will know when to free things */

	if (!tty_hung_up_p(filp))

		port->count--;

	port->blocked_open++;

	while (1) {

		set_current_state(TASK_INTERRUPTIBLE);

		if (tty_hung_up_p(filp) ||

				!(port->flags & ASYNC_INITIALIZED)) {

			if (port->flags & ASYNC_HUP_NOTIFY)

				retval = -EAGAIN;

			else

				retval = -ERESTARTSYS;

			break;

		}

		if (!(port->flags & ASYNC_CLOSING) &&

			  (do_clocal || (ch->imodem & ch->dcd)))

			break;

		if (signal_pending(current)) {

			retval = -ERESTARTSYS;

			break;

		}

		spin_unlock_irqrestore(&port->lock, flags);

		/*

		 * Allow someone else to be scheduled. We will occasionally go

		 * through this loop until one of the above conditions change.

		 * The below schedule call will allow other processes to enter

		 * and prevent this loop from hogging the cpu.

		 */

		schedule();

		spin_lock_irqsave(&port->lock, flags);

	}



	__set_current_state(TASK_RUNNING);

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

	if (!tty_hung_up_p(filp))

		port->count++;

	port->blocked_open--;



	spin_unlock_irqrestore(&port->lock, flags);



	if (retval)

		return retval;



	port->flags |= ASYNC_NORMAL_ACTIVE;

	return 0;

static void epca_raise_dtr_rts(struct tty_port *port0

{

}



static int pc_open(struct tty_struct *tty, struct file *filp)
@@ -978,7 +848,7 @@ static int pc_open(struct tty_struct *tty, struct file *filp) 
	port->flags |= ASYNC_INITIALIZED;

	spin_unlock_irqrestore(&port->lock, flags);



	retval = block_til_ready(tty, filp, ch);

	retval = tty_port_block_til_ready(port, tty, filp);

	if (retval)

		return retval;

	/*
@@ -1058,6 +928,11 @@ static const struct tty_operations pc_ops = { 
	.break_ctl = pc_send_break

};



static const struct tty_port_operations epca_port_ops = {

	.carrier_raised = epca_carrier_raised,

	.raise_dtr_rts = epca_raise_dtr_rts,

};



static int info_open(struct tty_struct *tty, struct file *filp)

{

	return 0;
@@ -1393,6 +1268,7 @@ static void post_fep_init(unsigned int crd) 
		u16 tseg, rseg;



		tty_port_init(&ch->port);

		ch->port.ops - &epca_port_ops;

		ch->brdchan = bc;

		ch->mailbox = gd;

		INIT_WORK(&ch->tqueue, do_softint);
@@ -1526,7 +1402,7 @@ static void post_fep_init(unsigned int crd) 
		ch->fepstartca = 0;

		ch->fepstopca = 0;



		ch->close_delay = 50;

		ch->port.close_delay = 50;



		spin_unlock_irqrestore(&epca_lock, flags);

	}
@@ -1647,7 +1523,7 @@ static void doevent(int crd) 
		if (event & MODEMCHG_IND) {

			/* A modem signal change has been indicated */

			ch->imodem = mstat;

			if (ch->port.flags & ASYNC_CHECK_CD) {

			if (test_bit(ASYNC_CHECK_CD, &ch->port.flags)) {

				/* We are now receiving dcd */

				if (mstat & ch->dcd)

					wake_up_interruptible(&ch->port.open_wait);
@@ -1894,9 +1770,9 @@ static void epcaparam(struct tty_struct *tty, struct channel *ch) 
		 * that the driver will wait on carrier detect.

		 */

		if (ts->c_cflag & CLOCAL)

			ch->port.flags &= ~ASYNC_CHECK_CD;

			clear_bit(ASYNC_CHECK_CD, &ch->port.flags);

		else

			ch->port.flags |= ASYNC_CHECK_CD;

			set_bit(ASYNC_CHECK_CD, &ch->port.flags);

		mval = ch->m_dtr | ch->m_rts;

	} /* End CBAUD not detected */

	iflag = termios2digi_i(ch, ts->c_iflag);
@@ -2373,7 +2249,7 @@ static void do_softint(struct work_struct *work) 
			if (test_and_clear_bit(EPCA_EVENT_HANGUP, &ch->event)) {

				tty_hangup(tty);

				wake_up_interruptible(&ch->port.open_wait);

				ch->port.flags &= ~ASYNC_NORMAL_ACTIVE;

				clear_bit(ASYNC_NORMAL_ACTIVE, &ch->port.flags);

			}

		}

		tty_kref_put(tty);

drivers/char/tty_port.c

+2 −1
Original line number Diff line number Diff line
@@ -286,7 +286,8 @@ int tty_port_close_start(struct tty_port *port, struct tty_struct *tty, struct f 
	port->flags |= ASYNC_CLOSING;

	tty->closing = 1;

	spin_unlock_irqrestore(&port->lock, flags);

	if (port->closing_wait != ASYNC_CLOSING_WAIT_NONE)

	if (port->flags & ASYNC_INITIALIZED &&

			port->closing_wait != ASYNC_CLOSING_WAIT_NONE)

		tty_wait_until_sent(tty, port->closing_wait);

	return 1;

}