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, 49 insertions, 72 deletions

diff --git a/drivers/usb/serial/mct_u232.c b/drivers/usb/serial/mct_u232.c
index 5fc2cef30e39..7bce4302a5f9 100644
--- a/drivers/usb/serial/mct_u232.c
+++ b/drivers/usb/serial/mct_u232.c
@@ -92,26 +92,25 @@ static int debug;
  */
 static int  mct_u232_startup             (struct usb_serial *serial);
 static void mct_u232_shutdown            (struct usb_serial *serial);
-static int  mct_u232_open                (struct usb_serial_port *port,
+static int  mct_u232_open                (struct tty_struct *tty,
+                                          struct usb_serial_port *port,
                                           struct file *filp);
-static void mct_u232_close               (struct usb_serial_port *port,
+static void mct_u232_close               (struct tty_struct *tty,
+                                          struct usb_serial_port *port,
                                           struct file *filp);
 static void mct_u232_read_int_callback   (struct urb *urb);
-static void mct_u232_set_termios         (struct usb_serial_port *port,
+static void mct_u232_set_termios         (struct tty_struct *tty,
+                                          struct usb_serial_port *port,
                                           struct ktermios * old);
-static int  mct_u232_ioctl               (struct usb_serial_port *port,
-                                          struct file * file,
-                                          unsigned int cmd,
-                                          unsigned long arg);
-static void mct_u232_break_ctl           (struct usb_serial_port *port,
+static void mct_u232_break_ctl           (struct tty_struct *tty,
                                           int break_state );
-static int  mct_u232_tiocmget            (struct usb_serial_port *port,
+static int  mct_u232_tiocmget            (struct tty_struct *tty,
                                           struct file *file);
-static int  mct_u232_tiocmset            (struct usb_serial_port *port,
+static int  mct_u232_tiocmset            (struct tty_struct *tty,
                                           struct file *file, unsigned int set,
                                           unsigned int clear);
-static void mct_u232_throttle            (struct usb_serial_port *port);
-static void mct_u232_unthrottle          (struct usb_serial_port *port);
+static void mct_u232_throttle            (struct tty_struct *tty);
+static void mct_u232_unthrottle          (struct tty_struct *tty);
 
 
 /*
@@ -149,7 +148,6 @@ static struct usb_serial_driver mct_u232_device = {
         .throttle =          mct_u232_throttle,
         .unthrottle =        mct_u232_unthrottle,
         .read_int_callback = mct_u232_read_int_callback,
-        .ioctl =             mct_u232_ioctl,
         .set_termios =       mct_u232_set_termios,
         .break_ctl =         mct_u232_break_ctl,
         .tiocmget =          mct_u232_tiocmget,
@@ -224,8 +222,8 @@ static int mct_u232_calculate_baud_rate(struct usb_serial *serial, speed_t value
         }
 }
 
-static int mct_u232_set_baud_rate(struct usb_serial *serial, struct usb_serial_port *port,
-                                  speed_t value)
+static int mct_u232_set_baud_rate(struct tty_struct *tty,
+        struct usb_serial *serial, struct usb_serial_port *port, speed_t value)
 {
         __le32 divisor;
         int rc;
@@ -243,7 +241,7 @@ static int mct_u232_set_baud_rate(struct usb_serial *serial, struct usb_serial_p
         if (rc < 0)     /*FIXME: What value speed results */
                 err("Set BAUD RATE %d failed (error = %d)", value, rc);
         else
-                tty_encode_baud_rate(port->tty, speed, speed);
+                tty_encode_baud_rate(tty, speed, speed);
         dbg("set_baud_rate: value: 0x%x, divisor: 0x%x", value, divisor);
 
         /* Mimic the MCT-supplied Windows driver (version 1.21P.0104), which
@@ -272,7 +270,7 @@ static int mct_u232_set_baud_rate(struct usb_serial *serial, struct usb_serial_p
                 err("Sending USB device request code %d failed (error = %d)", 
                     MCT_U232_SET_UNKNOWN1_REQUEST, rc);
 
-        if (port && C_CRTSCTS(port->tty)) {
+        if (port && C_CRTSCTS(tty)) {
            cts_enable_byte = 1;
         }
 
@@ -411,7 +409,8 @@ static void mct_u232_shutdown (struct usb_serial *serial)
         }
 } /* mct_u232_shutdown */
 
-static int  mct_u232_open (struct usb_serial_port *port, struct file *filp)
+static int  mct_u232_open (struct tty_struct *tty,
+                        struct usb_serial_port *port, struct file *filp)
 {
         struct usb_serial *serial = port->serial;
         struct mct_u232_private *priv = usb_get_serial_port_data(port);
@@ -437,7 +436,7 @@ static int  mct_u232_open (struct usb_serial_port *port, struct file *filp)
          * either.
          */
         spin_lock_irqsave(&priv->lock, flags);
-        if (port->tty->termios->c_cflag & CBAUD)
+        if (tty && (tty->termios->c_cflag & CBAUD))
                 priv->control_state = TIOCM_DTR | TIOCM_RTS;
         else
                 priv->control_state = 0;
@@ -481,15 +480,16 @@ error:
 } /* mct_u232_open */
 
 
-static void mct_u232_close (struct usb_serial_port *port, struct file *filp)
+static void mct_u232_close(struct tty_struct *tty,
+                        struct usb_serial_port *port, struct file *filp)
 {
         unsigned int c_cflag;
         unsigned int control_state;
         struct mct_u232_private *priv = usb_get_serial_port_data(port);
         dbg("%s port %d", __func__, port->number);
 
-        if (port->tty) {
-                c_cflag = port->tty->termios->c_cflag;
+        if (tty) {
+                c_cflag = tty->termios->c_cflag;
                 mutex_lock(&port->serial->disc_mutex);
                 if (c_cflag & HUPCL && !port->serial->disconnected) {
                         /* drop DTR and RTS */
@@ -553,7 +553,7 @@ static void mct_u232_read_int_callback (struct urb *urb)
          */
         if (urb->transfer_buffer_length > 2) {
                 int i;
-                tty = port->tty;
+                tty = port->port.tty;
                 if (urb->actual_length) {
                         for (i = 0; i < urb->actual_length ; ++i) {
                                 tty_insert_flip_char(tty, data[i], 0);
@@ -583,7 +583,7 @@ static void mct_u232_read_int_callback (struct urb *urb)
          * to look in to this before committing any code.
          */
         if (priv->last_lsr & MCT_U232_LSR_ERR) {
-                tty = port->tty;
+                tty = port->port.tty;
                 /* Overrun Error */
                 if (priv->last_lsr & MCT_U232_LSR_OE) {
                 }
@@ -606,12 +606,13 @@ exit:
                      __func__, retval);
 } /* mct_u232_read_int_callback */
 
-static void mct_u232_set_termios (struct usb_serial_port *port,
+static void mct_u232_set_termios (struct tty_struct *tty,
+                                  struct usb_serial_port *port,
                                   struct ktermios *old_termios)
 {
         struct usb_serial *serial = port->serial;
         struct mct_u232_private *priv = usb_get_serial_port_data(port);
-        struct ktermios *termios = port->tty->termios;
+        struct ktermios *termios = tty->termios;
         unsigned int cflag = termios->c_cflag;
         unsigned int old_cflag = old_termios->c_cflag;
         unsigned long flags;
@@ -638,7 +639,7 @@ static void mct_u232_set_termios (struct usb_serial_port *port,
                 mct_u232_set_modem_ctrl(serial, control_state);
         }
 
-        mct_u232_set_baud_rate(serial, port, tty_get_baud_rate(port->tty));
+        mct_u232_set_baud_rate(tty, serial, port, tty_get_baud_rate(tty));
 
         if ((cflag & CBAUD) == B0 ) {
                 dbg("%s: baud is B0", __func__);
@@ -689,8 +690,9 @@ static void mct_u232_set_termios (struct usb_serial_port *port,
         spin_unlock_irqrestore(&priv->lock, flags);
 } /* mct_u232_set_termios */
 
-static void mct_u232_break_ctl( struct usb_serial_port *port, int break_state )
+static void mct_u232_break_ctl(struct tty_struct *tty, int break_state)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct usb_serial *serial = port->serial;
         struct mct_u232_private *priv = usb_get_serial_port_data(port);
         unsigned char lcr;
@@ -709,8 +711,9 @@ static void mct_u232_break_ctl( struct usb_serial_port *port, int break_state )
 } /* mct_u232_break_ctl */
 
 
-static int mct_u232_tiocmget (struct usb_serial_port *port, struct file *file)
+static int mct_u232_tiocmget(struct tty_struct *tty, struct file *file)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct mct_u232_private *priv = usb_get_serial_port_data(port);
         unsigned int control_state;
         unsigned long flags;
@@ -724,9 +727,10 @@ static int mct_u232_tiocmget (struct usb_serial_port *port, struct file *file)
         return control_state;
 }
 
-static int mct_u232_tiocmset (struct usb_serial_port *port, struct file *file,
+static int mct_u232_tiocmset(struct tty_struct *tty, struct file *file,
                               unsigned int set, unsigned int clear)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct usb_serial *serial = port->serial;
         struct mct_u232_private *priv = usb_get_serial_port_data(port);
         unsigned int control_state;
@@ -751,73 +755,46 @@ static int mct_u232_tiocmset (struct usb_serial_port *port, struct file *file,
         return mct_u232_set_modem_ctrl(serial, control_state);
 }
 
-static int mct_u232_ioctl (struct usb_serial_port *port, struct file * file,
-                           unsigned int cmd, unsigned long arg)
-{
-        dbg("%scmd=0x%x", __func__, cmd);
-
-        /* Based on code from acm.c and others */
-        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;
-
-        default:
-                dbg("%s: arg not supported - 0x%04x", __func__,cmd);
-                return(-ENOIOCTLCMD);
-                break;
-        }
-        return 0;
-} /* mct_u232_ioctl */
-
-static void mct_u232_throttle (struct usb_serial_port *port)
+static void mct_u232_throttle(struct tty_struct *tty)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct mct_u232_private *priv = usb_get_serial_port_data(port);
         unsigned long flags;
         unsigned int control_state;
-        struct tty_struct *tty;
 
-        tty = port->tty;
         dbg("%s - port %d", __func__, port->number);
 
         spin_lock_irqsave(&priv->lock, flags);
         priv->rx_flags |= THROTTLED;
         if (C_CRTSCTS(tty)) {
-          priv->control_state &= ~TIOCM_RTS;
-          control_state = priv->control_state;
-          spin_unlock_irqrestore(&priv->lock, flags);
-          (void) mct_u232_set_modem_ctrl(port->serial, control_state);
+                priv->control_state &= ~TIOCM_RTS;
+                control_state = priv->control_state;
+                spin_unlock_irqrestore(&priv->lock, flags);
+                (void) mct_u232_set_modem_ctrl(port->serial, control_state);
         } else {
-          spin_unlock_irqrestore(&priv->lock, flags);
+                spin_unlock_irqrestore(&priv->lock, flags);
         }
 }
 
 
-static void mct_u232_unthrottle (struct usb_serial_port *port)
+static void mct_u232_unthrottle(struct tty_struct *tty)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct mct_u232_private *priv = usb_get_serial_port_data(port);
         unsigned long flags;
         unsigned int control_state;
-        struct tty_struct *tty;
 
         dbg("%s - port %d", __func__, port->number);
 
-        tty = port->tty;
         spin_lock_irqsave(&priv->lock, flags);
         if ((priv->rx_flags & THROTTLED) && C_CRTSCTS(tty)) {
-          priv->rx_flags &= ~THROTTLED;
-          priv->control_state |= TIOCM_RTS;
-          control_state = priv->control_state;
-          spin_unlock_irqrestore(&priv->lock, flags);
-          (void) mct_u232_set_modem_ctrl(port->serial, control_state);
+                priv->rx_flags &= ~THROTTLED;
+                priv->control_state |= TIOCM_RTS;
+                control_state = priv->control_state;
+                spin_unlock_irqrestore(&priv->lock, flags);
+                (void) mct_u232_set_modem_ctrl(port->serial, control_state);
         } else {
-          spin_unlock_irqrestore(&priv->lock, flags);
+                spin_unlock_irqrestore(&priv->lock, flags);
         }
 }