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, 43 insertions, 31 deletions

diff --git a/drivers/usb/serial/kl5kusb105.c b/drivers/usb/serial/kl5kusb105.c
index 79787eda9524..4a38ec8f5fe3 100644
--- a/drivers/usb/serial/kl5kusb105.c
+++ b/drivers/usb/serial/kl5kusb105.c
@@ -74,29 +74,33 @@ static int debug;
  */
 static int  klsi_105_startup             (struct usb_serial *serial);
 static void klsi_105_shutdown            (struct usb_serial *serial);
-static int  klsi_105_open                (struct usb_serial_port *port,
+static int  klsi_105_open                (struct tty_struct *tty,
+                                          struct usb_serial_port *port,
                                           struct file *filp);
-static void klsi_105_close               (struct usb_serial_port *port,
+static void klsi_105_close               (struct tty_struct *tty,
+                                          struct usb_serial_port *port,
                                           struct file *filp);
-static int  klsi_105_write               (struct usb_serial_port *port,
+static int  klsi_105_write               (struct tty_struct *tty,
+                                          struct usb_serial_port *port,
                                           const unsigned char *buf,
                                           int count);
 static void klsi_105_write_bulk_callback (struct urb *urb);
-static int  klsi_105_chars_in_buffer     (struct usb_serial_port *port);
-static int  klsi_105_write_room          (struct usb_serial_port *port);
+static int  klsi_105_chars_in_buffer     (struct tty_struct *tty);
+static int  klsi_105_write_room          (struct tty_struct *tty);
 
 static void klsi_105_read_bulk_callback  (struct urb *urb);
-static void klsi_105_set_termios         (struct usb_serial_port *port,
+static void klsi_105_set_termios         (struct tty_struct *tty,
+                                          struct usb_serial_port *port,
                                           struct ktermios *old);
-static void klsi_105_throttle            (struct usb_serial_port *port);
-static void klsi_105_unthrottle          (struct usb_serial_port *port);
+static void klsi_105_throttle            (struct tty_struct *tty);
+static void klsi_105_unthrottle          (struct tty_struct *tty);
 /*
-static void klsi_105_break_ctl           (struct usb_serial_port *port,
+static void klsi_105_break_ctl           (struct tty_struct *tty,
                                           int break_state );
  */
-static int  klsi_105_tiocmget            (struct usb_serial_port *port,
+static int  klsi_105_tiocmget            (struct tty_struct *tty,
                                           struct file *file);
-static int  klsi_105_tiocmset            (struct usb_serial_port *port,
+static int  klsi_105_tiocmset            (struct tty_struct *tty,
                                           struct file *file, unsigned int set,
                                           unsigned int clear);
 
@@ -361,7 +365,8 @@ static void klsi_105_shutdown (struct usb_serial *serial)
         }
 } /* klsi_105_shutdown */
 
-static int  klsi_105_open (struct usb_serial_port *port, struct file *filp)
+static int  klsi_105_open(struct tty_struct *tty,
+                        struct usb_serial_port *port, struct file *filp)
 {
         struct klsi_105_private *priv = usb_get_serial_port_data(port);
         int retval = 0;
@@ -375,7 +380,7 @@ static int  klsi_105_open (struct usb_serial_port *port, struct file *filp)
 
         /* force low_latency on so that our tty_push actually forces
          * the data through
-         * port->tty->low_latency = 1; */
+         * tty->low_latency = 1; */
 
         /* Do a defined restart:
          * Set up sane default baud rate and send the 'READ_ON'
@@ -393,12 +398,12 @@ static int  klsi_105_open (struct usb_serial_port *port, struct file *filp)
         
         /* set up termios structure */
         spin_lock_irqsave (&priv->lock, flags);
-        priv->termios.c_iflag = port->tty->termios->c_iflag;
-        priv->termios.c_oflag = port->tty->termios->c_oflag;
-        priv->termios.c_cflag = port->tty->termios->c_cflag;
-        priv->termios.c_lflag = port->tty->termios->c_lflag;
+        priv->termios.c_iflag = tty->termios->c_iflag;
+        priv->termios.c_oflag = tty->termios->c_oflag;
+        priv->termios.c_cflag = tty->termios->c_cflag;
+        priv->termios.c_lflag = tty->termios->c_lflag;
         for (i=0; i<NCCS; i++)
-                priv->termios.c_cc[i] = port->tty->termios->c_cc[i];
+                priv->termios.c_cc[i] = tty->termios->c_cc[i];
         priv->cfg.pktlen   = cfg.pktlen;
         priv->cfg.baudrate = cfg.baudrate;
         priv->cfg.databits = cfg.databits;
@@ -452,7 +457,8 @@ exit:
 } /* klsi_105_open */
 
 
-static void klsi_105_close (struct usb_serial_port *port, struct file *filp)
+static void klsi_105_close(struct tty_struct *tty,
+                        struct usb_serial_port *port, struct file *filp)
 {
         struct klsi_105_private *priv = usb_get_serial_port_data(port);
         int rc;
@@ -493,8 +499,8 @@ static void klsi_105_close (struct usb_serial_port *port, struct file *filp)
 #define KLSI_105_DATA_OFFSET    2   /* in the bulk urb data block */
 
 
-static int klsi_105_write (struct usb_serial_port *port,
-                           const unsigned char *buf, int count)
+static int klsi_105_write(struct tty_struct *tty,
+        struct usb_serial_port *port, const unsigned char *buf, int count)
 {
         struct klsi_105_private *priv = usb_get_serial_port_data(port);
         int result, size;
@@ -584,8 +590,9 @@ static void klsi_105_write_bulk_callback ( struct urb *urb)
 
 
 /* return number of characters currently in the writing process */
-static int klsi_105_chars_in_buffer (struct usb_serial_port *port)
+static int klsi_105_chars_in_buffer (struct tty_struct *tty)
 {
+        struct usb_serial_port *port = tty->driver_data;
         int chars = 0;
         int i;
         unsigned long flags;
@@ -605,8 +612,9 @@ static int klsi_105_chars_in_buffer (struct usb_serial_port *port)
         return (chars);
 }
 
-static int klsi_105_write_room (struct usb_serial_port *port)
+static int klsi_105_write_room (struct tty_struct *tty)
 {
+        struct usb_serial_port *port = tty->driver_data;
         unsigned long flags;
         int i;
         int room = 0;
@@ -660,7 +668,7 @@ static void klsi_105_read_bulk_callback (struct urb *urb)
         } else {
                 int bytes_sent = ((__u8 *) data)[0] +
                                  ((unsigned int) ((__u8 *) data)[1] << 8);
-                tty = port->tty;
+                tty = port->port.tty;
                 /* we should immediately resubmit the URB, before attempting
                  * to pass the data on to the tty layer. But that needs locking
                  * against re-entry an then mixed-up data because of
@@ -699,11 +707,11 @@ static void klsi_105_read_bulk_callback (struct urb *urb)
 } /* klsi_105_read_bulk_callback */
 
 
-static void klsi_105_set_termios (struct usb_serial_port *port,
+static void klsi_105_set_termios (struct tty_struct *tty,
+                                  struct usb_serial_port *port,
                                   struct ktermios *old_termios)
 {
         struct klsi_105_private *priv = usb_get_serial_port_data(port);
-        struct tty_struct *tty = port->tty;
         unsigned int iflag = tty->termios->c_iflag;
         unsigned int old_iflag = old_termios->c_iflag;
         unsigned int cflag = tty->termios->c_cflag;
@@ -863,8 +871,9 @@ static void klsi_105_set_termios (struct usb_serial_port *port,
 
 
 #if 0
-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 = (struct mct_u232_private *)port->private;
         unsigned char lcr = priv->last_lcr;
@@ -878,8 +887,9 @@ static void mct_u232_break_ctl( struct usb_serial_port *port, int break_state )
 } /* mct_u232_break_ctl */
 #endif
 
-static int klsi_105_tiocmget (struct usb_serial_port *port, struct file *file)
+static int klsi_105_tiocmget (struct tty_struct *tty, struct file *file)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct klsi_105_private *priv = usb_get_serial_port_data(port);
         unsigned long flags;
         int rc;
@@ -900,7 +910,7 @@ static int klsi_105_tiocmget (struct usb_serial_port *port, struct file *file)
         return (int)line_state;
 }
 
-static int klsi_105_tiocmset (struct usb_serial_port *port, struct file *file,
+static int klsi_105_tiocmset (struct tty_struct *tty, struct file *file,
                               unsigned int set, unsigned int clear)
 {
         int retval = -EINVAL;
@@ -929,14 +939,16 @@ static int klsi_105_tiocmset (struct usb_serial_port *port, struct file *file,
         return retval;
 }
 
-static void klsi_105_throttle (struct usb_serial_port *port)
+static void klsi_105_throttle (struct tty_struct *tty)
 {
+        struct usb_serial_port *port = tty->driver_data;
         dbg("%s - port %d", __func__, port->number);
         usb_kill_urb(port->read_urb);
 }
 
-static void klsi_105_unthrottle (struct usb_serial_port *port)
+static void klsi_105_unthrottle (struct tty_struct *tty)
 {
+        struct usb_serial_port *port = tty->driver_data;
         int result;
 
         dbg("%s - port %d", __func__, port->number);