tty: Bring the usb tty port structure into more use

This allows us to clean stuff up, but is probably also going to cause
some app breakage with buggy apps as we now implement proper POSIX behaviour
for USB ports matching all the other ports. This does also mean other apps
that break on USB will now work properly.

Signed-off-by: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 23 insertions, 58 deletions

diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c
index e568710b263..669f9384853 100644
--- a/drivers/usb/serial/cypress_m8.c
+++ b/drivers/usb/serial/cypress_m8.c
@@ -174,8 +174,8 @@ static int  cypress_ca42v2_startup(struct usb_serial *serial);
 static void cypress_shutdown(struct usb_serial *serial);
 static int  cypress_open(struct tty_struct *tty,
 			struct usb_serial_port *port, struct file *filp);
-static void cypress_close(struct tty_struct *tty,
-			struct usb_serial_port *port, struct file *filp);
+static void cypress_close(struct usb_serial_port *port);
+static void cypress_dtr_rts(struct usb_serial_port *port, int on);
 static int  cypress_write(struct tty_struct *tty, struct usb_serial_port *port,
 			const unsigned char *buf, int count);
 static void cypress_send(struct usb_serial_port *port);
@@ -218,6 +218,7 @@ static struct usb_serial_driver cypress_earthmate_device = {
 	.shutdown =			cypress_shutdown,
 	.open =				cypress_open,
 	.close =			cypress_close,
+	.dtr_rts =			cypress_dtr_rts,
 	.write =			cypress_write,
 	.write_room =			cypress_write_room,
 	.ioctl =			cypress_ioctl,
@@ -244,6 +245,7 @@ static struct usb_serial_driver cypress_hidcom_device = {
 	.shutdown =			cypress_shutdown,
 	.open =				cypress_open,
 	.close =			cypress_close,
+	.dtr_rts =			cypress_dtr_rts,
 	.write =			cypress_write,
 	.write_room =			cypress_write_room,
 	.ioctl =			cypress_ioctl,
@@ -270,6 +272,7 @@ static struct usb_serial_driver cypress_ca42v2_device = {
 	.shutdown =			cypress_shutdown,
 	.open =				cypress_open,
 	.close =			cypress_close,
+	.dtr_rts =			cypress_dtr_rts,
 	.write =			cypress_write,
 	.write_room =			cypress_write_room,
 	.ioctl =			cypress_ioctl,
@@ -656,11 +659,7 @@ static int cypress_open(struct tty_struct *tty,
 	priv->rx_flags = 0;
 	spin_unlock_irqrestore(&priv->lock, flags);
 
-	/* raise both lines and set termios */
-	spin_lock_irqsave(&priv->lock, flags);
-	priv->line_control = CONTROL_DTR | CONTROL_RTS;
-	priv->cmd_ctrl = 1;
-	spin_unlock_irqrestore(&priv->lock, flags);
+	/* Set termios */
 	result = cypress_write(tty, port, NULL, 0);
 
 	if (result) {
@@ -694,76 +693,42 @@ static int cypress_open(struct tty_struct *tty,
 							__func__, result);
 		cypress_set_dead(port);
 	}
-
+	port->port.drain_delay = 256;
 	return result;
 } /* cypress_open */
 
+static void cypress_dtr_rts(struct usb_serial_port *port, int on)
+{
+	struct cypress_private *priv = usb_get_serial_port_data(port);
+	/* drop dtr and rts */
+	priv = usb_get_serial_port_data(port);
+	spin_lock_irq(&priv->lock);
+	if (on == 0)
+		priv->line_control = 0;
+	else 
+		priv->line_control = CONTROL_DTR | CONTROL_RTS;
+	priv->cmd_ctrl = 1;
+	spin_unlock_irq(&priv->lock);
+	cypress_write(NULL, port, NULL, 0);
+}
 
-static void cypress_close(struct tty_struct *tty,
-			struct usb_serial_port *port, struct file *filp)
+static void cypress_close(struct usb_serial_port *port)
 {
 	struct cypress_private *priv = usb_get_serial_port_data(port);
-	unsigned int c_cflag;
-	int bps;
-	long timeout;
-	wait_queue_t wait;
 
 	dbg("%s - port %d", __func__, port->number);
 
-	/* wait for data to drain from buffer */
-	spin_lock_irq(&priv->lock);
-	timeout = CYPRESS_CLOSING_WAIT;
-	init_waitqueue_entry(&wait, current);
-	add_wait_queue(&tty->write_wait, &wait);
-	for (;;) {
-		set_current_state(TASK_INTERRUPTIBLE);
-		if (cypress_buf_data_avail(priv->buf) == 0
-		|| timeout == 0 || signal_pending(current)
-		/* without mutex, allowed due to harmless failure mode */
-		|| port->serial->disconnected)
-			break;
-		spin_unlock_irq(&priv->lock);
-		timeout = schedule_timeout(timeout);
-		spin_lock_irq(&priv->lock);
-	}
-	set_current_state(TASK_RUNNING);
-	remove_wait_queue(&tty->write_wait, &wait);
-	/* clear out any remaining data in the buffer */
-	cypress_buf_clear(priv->buf);
-	spin_unlock_irq(&priv->lock);
-
 	/* writing is potentially harmful, lock must be taken */
 	mutex_lock(&port->serial->disc_mutex);
 	if (port->serial->disconnected) {
 		mutex_unlock(&port->serial->disc_mutex);
 		return;
 	}
-	/* wait for characters to drain from device */
-	if (tty) {
-		bps = tty_get_baud_rate(tty);
-		if (bps > 1200)
-			timeout = max((HZ * 2560) / bps, HZ / 10);
-		else
-			timeout = 2 * HZ;
-		schedule_timeout_interruptible(timeout);
-	}
-
+	cypress_buf_clear(priv->buf);
 	dbg("%s - stopping urbs", __func__);
 	usb_kill_urb(port->interrupt_in_urb);
 	usb_kill_urb(port->interrupt_out_urb);
 
-	if (tty) {
-		c_cflag = tty->termios->c_cflag;
-		if (c_cflag & HUPCL) {
-			/* drop dtr and rts */
-			priv = usb_get_serial_port_data(port);
-			spin_lock_irq(&priv->lock);
-			priv->line_control = 0;
-			priv->cmd_ctrl = 1;
-			spin_unlock_irq(&priv->lock);
-			cypress_write(tty, port, NULL, 0);
-		}
-	}
 
 	if (stats)
 		dev_info(&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n",