usb_serial: API all change

USB serial likes to use port->tty back pointers for the real work it does and
to do so without any actual locking. Unfortunately when you consider hangup
events, hangup/parallel reopen or even worse hangup followed by parallel close
events the tty->port and port->tty pointers are not guaranteed to be the same
as port->tty is the active tty while tty->port is the port the tty may or
may not still be attached to.

So rework the entire API to pass the tty struct. For console cases we need
to pass both for now. This shows up multiple drivers that immediately crash
with USB console some of which have been fixed in the process.

Longer term we need a proper tty as console abstraction

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 56 insertions, 71 deletions

diff --git a/drivers/usb/serial/digi_acceleport.c b/drivers/usb/serial/digi_acceleport.c
index 28bc6fc..dc92dbf 100644
--- a/drivers/usb/serial/digi_acceleport.c
+++ b/drivers/usb/serial/digi_acceleport.c
@@ -15,7 +15,7 @@
 *  Al Borchers (borchers@steinerpoint.com)
 * 
 * (12/03/2001) gkh
-*	switched to using port->open_count instead of private version.
+*	switched to using port->port.count instead of private version.
 *	Removed port->active
 *
 * (04/08/2001) gb
@@ -441,22 +441,23 @@ static int digi_set_modem_signals(struct usb_serial_port *port,
 	unsigned int modem_signals, int interruptible);
 static int digi_transmit_idle(struct usb_serial_port *port,
 	unsigned long timeout);
-static void digi_rx_throttle (struct usb_serial_port *port);
-static void digi_rx_unthrottle (struct usb_serial_port *port);
-static void digi_set_termios(struct usb_serial_port *port,
-	struct ktermios *old_termios);
-static void digi_break_ctl(struct usb_serial_port *port, int break_state);
-static int digi_ioctl(struct usb_serial_port *port, struct file *file,
-	unsigned int cmd, unsigned long arg);
-static int digi_tiocmget(struct usb_serial_port *port, struct file *file);
-static int digi_tiocmset(struct usb_serial_port *port, struct file *file,
+static void digi_rx_throttle (struct tty_struct *tty);
+static void digi_rx_unthrottle (struct tty_struct *tty);
+static void digi_set_termios(struct tty_struct *tty,
+		struct usb_serial_port *port, struct ktermios *old_termios);
+static void digi_break_ctl(struct tty_struct *tty, int break_state);
+static int digi_tiocmget(struct tty_struct *tty, struct file *file);
+static int digi_tiocmset(struct tty_struct *tty, struct file *file,
 	unsigned int set, unsigned int clear);
-static int digi_write(struct usb_serial_port *port, const unsigned char *buf, int count);
+static int digi_write(struct tty_struct *tty, struct usb_serial_port *port,
+	const unsigned char *buf, int count);
 static void digi_write_bulk_callback(struct urb *urb);
-static int digi_write_room(struct usb_serial_port *port);
-static int digi_chars_in_buffer(struct usb_serial_port *port);
-static int digi_open(struct usb_serial_port *port, struct file *filp);
-static void digi_close(struct usb_serial_port *port, struct file *filp);
+static int digi_write_room(struct tty_struct *tty);
+static int digi_chars_in_buffer(struct tty_struct *tty);
+static int digi_open(struct tty_struct *tty, struct usb_serial_port *port,
+	struct file *filp);
+static void digi_close(struct tty_struct *tty, struct usb_serial_port *port,
+	struct file *filp);
 static int digi_startup_device(struct usb_serial *serial);
 static int digi_startup(struct usb_serial *serial);
 static void digi_shutdown(struct usb_serial *serial);
@@ -516,7 +517,6 @@ static struct usb_serial_driver digi_acceleport_2_device = {
 	.chars_in_buffer =		digi_chars_in_buffer,
 	.throttle =			digi_rx_throttle,
 	.unthrottle =			digi_rx_unthrottle,
-	.ioctl =			digi_ioctl,
 	.set_termios =			digi_set_termios,
 	.break_ctl =			digi_break_ctl,
 	.tiocmget =			digi_tiocmget,
@@ -543,7 +543,6 @@ static struct usb_serial_driver digi_acceleport_4_device = {
 	.chars_in_buffer =		digi_chars_in_buffer,
 	.throttle =			digi_rx_throttle,
 	.unthrottle =			digi_rx_unthrottle,
-	.ioctl =			digi_ioctl,
 	.set_termios =			digi_set_termios,
 	.break_ctl =			digi_break_ctl,
 	.tiocmget =			digi_tiocmget,
@@ -604,7 +603,7 @@ static void digi_wakeup_write_lock(struct work_struct *work)
 
 static void digi_wakeup_write(struct usb_serial_port *port)
 {
-	tty_wakeup(port->tty);
+	tty_wakeup(port->port.tty);
 }
 
 
@@ -856,9 +855,10 @@ static int digi_transmit_idle(struct usb_serial_port *port,
 }
 
 
-static void digi_rx_throttle(struct usb_serial_port *port)
+static void digi_rx_throttle(struct tty_struct *tty)
 {
 	unsigned long flags;
+	struct usb_serial_port *port = tty->driver_data;
 	struct digi_port *priv = usb_get_serial_port_data(port);
 
 
@@ -872,10 +872,11 @@ static void digi_rx_throttle(struct usb_serial_port *port)
 }
 
 
-static void digi_rx_unthrottle(struct usb_serial_port *port)
+static void digi_rx_unthrottle(struct tty_struct *tty)
 {
 	int ret = 0;
 	unsigned long flags;
+	struct usb_serial_port *port = tty->driver_data;
 	struct digi_port *priv = usb_get_serial_port_data(port);
 
 	dbg("digi_rx_unthrottle: TOP: port=%d", priv->dp_port_num);
@@ -900,12 +901,10 @@ static void digi_rx_unthrottle(struct usb_serial_port *port)
 }
 
 
-static void digi_set_termios(struct usb_serial_port *port,
-					struct ktermios *old_termios)
+static void digi_set_termios(struct tty_struct *tty, 
+		struct usb_serial_port *port, struct ktermios *old_termios)
 {
-
 	struct digi_port *priv = usb_get_serial_port_data(port);
-	struct tty_struct *tty = port->tty;
 	unsigned int iflag = tty->termios->c_iflag;
 	unsigned int cflag = tty->termios->c_cflag;
 	unsigned int old_iflag = old_termios->c_iflag;
@@ -1088,8 +1087,9 @@ static void digi_set_termios(struct usb_serial_port *port,
 }
 
 
-static void digi_break_ctl(struct usb_serial_port *port, int break_state)
+static void digi_break_ctl(struct tty_struct *tty, int break_state)
 {
+	struct usb_serial_port *port = tty->driver_data;
 	unsigned char buf[4];
 
 	buf[0] = DIGI_CMD_BREAK_CONTROL;
@@ -1100,8 +1100,9 @@ static void digi_break_ctl(struct usb_serial_port *port, int break_state)
 }
 
 
-static int digi_tiocmget(struct usb_serial_port *port, struct file *file)
+static int digi_tiocmget(struct tty_struct *tty, struct file *file)
 {
+	struct usb_serial_port *port = tty->driver_data;
 	struct digi_port *priv = usb_get_serial_port_data(port);
 	unsigned int val;
 	unsigned long flags;
@@ -1115,9 +1116,10 @@ static int digi_tiocmget(struct usb_serial_port *port, struct file *file)
 }
 
 
-static int digi_tiocmset(struct usb_serial_port *port, struct file *file,
+static int digi_tiocmset(struct tty_struct *tty, struct file *file,
 	unsigned int set, unsigned int clear)
 {
+	struct usb_serial_port *port = tty->driver_data;
 	struct digi_port *priv = usb_get_serial_port_data(port);
 	unsigned int val;
 	unsigned long flags;
@@ -1131,27 +1133,8 @@ static int digi_tiocmset(struct usb_serial_port *port, struct file *file,
 }
 
 
-static int digi_ioctl(struct usb_serial_port *port, struct file *file,
-	unsigned int cmd, unsigned long arg)
-{
-	struct digi_port *priv = usb_get_serial_port_data(port);
-	dbg("digi_ioctl: TOP: port=%d, cmd=0x%x", priv->dp_port_num, cmd);
-
-	switch (cmd) {
-	case TIOCMIWAIT:
-		/* wait for any of the 4 modem inputs (DCD,RI,DSR,CTS)*/
-		/* TODO */
-		return 0;
-	case TIOCGICOUNT:
-		/* return count of modemline transitions */
-		/* TODO */
-		return 0;
-	}
-	return -ENOIOCTLCMD;
-
-}
-
-static int digi_write(struct usb_serial_port *port, const unsigned char *buf, int count)
+static int digi_write(struct tty_struct *tty, struct usb_serial_port *port,
+					const unsigned char *buf, int count)
 {
 
 	int ret,data_len,new_len;
@@ -1261,7 +1244,7 @@ static void digi_write_bulk_callback(struct urb *urb)
 	/* try to send any buffered data on this port, if it is open */
 	spin_lock(&priv->dp_port_lock);
 	priv->dp_write_urb_in_use = 0;
-	if (port->open_count && port->write_urb->status != -EINPROGRESS
+	if (port->port.count && port->write_urb->status != -EINPROGRESS
 	    && priv->dp_out_buf_len > 0) {
 		*((unsigned char *)(port->write_urb->transfer_buffer))
 			= (unsigned char)DIGI_CMD_SEND_DATA;
@@ -1288,11 +1271,11 @@ static void digi_write_bulk_callback(struct urb *urb)
 			__func__, ret, priv->dp_port_num);
 }
 
-static int digi_write_room(struct usb_serial_port *port)
+static int digi_write_room(struct tty_struct *tty)
 {
-
-	int room;
+	struct usb_serial_port *port = tty->driver_data;
 	struct digi_port *priv = usb_get_serial_port_data(port);
+	int room;
 	unsigned long flags = 0;
 
 	spin_lock_irqsave(&priv->dp_port_lock, flags);
@@ -1308,12 +1291,11 @@ static int digi_write_room(struct usb_serial_port *port)
 
 }
 
-static int digi_chars_in_buffer(struct usb_serial_port *port)
+static int digi_chars_in_buffer(struct tty_struct *tty)
 {
-
+	struct usb_serial_port *port = tty->driver_data;
 	struct digi_port *priv = usb_get_serial_port_data(port);
 
-
 	if (port->write_urb->status == -EINPROGRESS
 	    || priv->dp_write_urb_in_use) {
 		dbg("digi_chars_in_buffer: port=%d, chars=%d",
@@ -1329,7 +1311,8 @@ static int digi_chars_in_buffer(struct usb_serial_port *port)
 }
 
 
-static int digi_open(struct usb_serial_port *port, struct file *filp)
+static int digi_open(struct tty_struct *tty, struct usb_serial_port *port,
+				struct file *filp)
 {
 	int ret;
 	unsigned char buf[32];
@@ -1338,7 +1321,7 @@ static int digi_open(struct usb_serial_port *port, struct file *filp)
 	unsigned long flags = 0;
 
 	dbg("digi_open: TOP: port=%d, open_count=%d",
-		priv->dp_port_num, port->open_count);
+		priv->dp_port_num, port->port.count);
 
 	/* be sure the device is started up */
 	if (digi_startup_device(port->serial) != 0)
@@ -1380,9 +1363,11 @@ static int digi_open(struct usb_serial_port *port, struct file *filp)
 		dbg("digi_open: write oob failed, ret=%d", ret);
 
 	/* set termios settings */
-	not_termios.c_cflag = ~port->tty->termios->c_cflag;
-	not_termios.c_iflag = ~port->tty->termios->c_iflag;
-	digi_set_termios(port, &not_termios);
+	if (tty) {
+		not_termios.c_cflag = ~tty->termios->c_cflag;
+		not_termios.c_iflag = ~tty->termios->c_iflag;
+		digi_set_termios(tty, port, &not_termios);
+	}
 
 	/* set DTR and RTS */
 	digi_set_modem_signals(port, TIOCM_DTR|TIOCM_RTS, 1);
@@ -1391,16 +1376,16 @@ static int digi_open(struct usb_serial_port *port, struct file *filp)
 }
 
 
-static void digi_close(struct usb_serial_port *port, struct file *filp)
+static void digi_close(struct tty_struct *tty, struct usb_serial_port *port,
+				struct file *filp)
 {
 	DEFINE_WAIT(wait);
 	int ret;
 	unsigned char buf[32];
-	struct tty_struct *tty = port->tty;
 	struct digi_port *priv = usb_get_serial_port_data(port);
 
 	dbg("digi_close: TOP: port=%d, open_count=%d",
-		priv->dp_port_num, port->open_count);
+		priv->dp_port_num, port->port.count);
 
 	mutex_lock(&port->serial->disc_mutex);
 	/* if disconnected, just clear flags */
@@ -1663,7 +1648,7 @@ static int digi_read_inb_callback(struct urb *urb)
 {
 
 	struct usb_serial_port *port = urb->context;
-	struct tty_struct *tty = port->tty;
+	struct tty_struct *tty = port->port.tty;
 	struct digi_port *priv = usb_get_serial_port_data(port);
 	int opcode = ((unsigned char *)urb->transfer_buffer)[0];
 	int len = ((unsigned char *)urb->transfer_buffer)[1];
@@ -1675,7 +1660,7 @@ static int digi_read_inb_callback(struct urb *urb)
 
 	/* do not process callbacks on closed ports */
 	/* but do continue the read chain */
-	if (port->open_count == 0)
+	if (port->port.count == 0)
 		return 0;
 
 	/* short/multiple packet check */
@@ -1785,17 +1770,17 @@ static int digi_read_oob_callback(struct urb *urb)
 			if (val & DIGI_READ_INPUT_SIGNALS_CTS) {
 				priv->dp_modem_signals |= TIOCM_CTS;
 				/* port must be open to use tty struct */
-				if (port->open_count
-					&& port->tty->termios->c_cflag & CRTSCTS) {
-					port->tty->hw_stopped = 0;
+				if (port->port.count
+					&& port->port.tty->termios->c_cflag & CRTSCTS) {
+					port->port.tty->hw_stopped = 0;
 					digi_wakeup_write(port);
 				}
 			} else {
 				priv->dp_modem_signals &= ~TIOCM_CTS;
 				/* port must be open to use tty struct */
-				if (port->open_count
-					&& port->tty->termios->c_cflag & CRTSCTS) {
-					port->tty->hw_stopped = 1;
+				if (port->port.count
+					&& port->port.tty->termios->c_cflag & CRTSCTS) {
+					port->port.tty->hw_stopped = 1;
 				}
 			}
 			if (val & DIGI_READ_INPUT_SIGNALS_DSR)