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, 58 insertions, 44 deletions

diff --git a/drivers/usb/serial/whiteheat.c b/drivers/usb/serial/whiteheat.c
index 665aa77a917b..b07d6a5cac31 100644
--- a/drivers/usb/serial/whiteheat.c
+++ b/drivers/usb/serial/whiteheat.c
@@ -142,18 +142,18 @@ static int  whiteheat_firmware_attach	(struct usb_serial *serial);
 /* function prototypes for the Connect Tech WhiteHEAT serial converter */
 static int  whiteheat_attach            (struct usb_serial *serial);
 static void whiteheat_shutdown          (struct usb_serial *serial);
-static int  whiteheat_open              (struct usb_serial_port *port, struct file *filp);
-static void whiteheat_close             (struct usb_serial_port *port, struct file *filp);
-static int  whiteheat_write             (struct usb_serial_port *port, const unsigned char *buf, int count);
-static int  whiteheat_write_room        (struct usb_serial_port *port);
-static int  whiteheat_ioctl             (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg);
-static void whiteheat_set_termios       (struct usb_serial_port *port, struct ktermios * old);
-static int  whiteheat_tiocmget          (struct usb_serial_port *port, struct file *file);
-static int  whiteheat_tiocmset          (struct usb_serial_port *port, struct file *file, unsigned int set, unsigned int clear);
-static void whiteheat_break_ctl         (struct usb_serial_port *port, int break_state);
-static int  whiteheat_chars_in_buffer   (struct usb_serial_port *port);
-static void whiteheat_throttle          (struct usb_serial_port *port);
-static void whiteheat_unthrottle        (struct usb_serial_port *port);
+static int  whiteheat_open              (struct tty_struct *tty, struct usb_serial_port *port, struct file *filp);
+static void whiteheat_close             (struct tty_struct *tty, struct usb_serial_port *port, struct file *filp);
+static int  whiteheat_write             (struct tty_struct *tty, struct usb_serial_port *port, const unsigned char *buf, int count);
+static int  whiteheat_write_room        (struct tty_struct *tty);
+static int  whiteheat_ioctl             (struct tty_struct *tty, struct file * file, unsigned int cmd, unsigned long arg);
+static void whiteheat_set_termios       (struct tty_struct *tty, struct usb_serial_port *port, struct ktermios * old);
+static int  whiteheat_tiocmget          (struct tty_struct *tty, struct file *file);
+static int  whiteheat_tiocmset          (struct tty_struct *tty, struct file *file, unsigned int set, unsigned int clear);
+static void whiteheat_break_ctl         (struct tty_struct *tty, int break_state);
+static int  whiteheat_chars_in_buffer   (struct tty_struct *tty);
+static void whiteheat_throttle          (struct tty_struct *tty);
+static void whiteheat_unthrottle        (struct tty_struct *tty);
 static void whiteheat_read_callback     (struct urb *urb);
 static void whiteheat_write_callback    (struct urb *urb);
 
@@ -246,7 +246,7 @@ static void rx_data_softint(struct work_struct *work);
 static int firm_send_command(struct usb_serial_port *port, __u8 command, __u8 *data, __u8 datasize);
 static int firm_open(struct usb_serial_port *port);
 static int firm_close(struct usb_serial_port *port);
-static int firm_setup_port(struct usb_serial_port *port);
+static int firm_setup_port(struct tty_struct *tty);
 static int firm_set_rts(struct usb_serial_port *port, __u8 onoff);
 static int firm_set_dtr(struct usb_serial_port *port, __u8 onoff);
 static int firm_set_break(struct usb_serial_port *port, __u8 onoff);
@@ -613,7 +613,8 @@ static void whiteheat_shutdown (struct usb_serial *serial)
 }
 
 
-static int whiteheat_open (struct usb_serial_port *port, struct file *filp)
+static int whiteheat_open (struct tty_struct *tty,
+                        struct usb_serial_port *port, struct file *filp)
 {
         int             retval = 0;
         struct ktermios old_term;
@@ -624,7 +625,8 @@ static int whiteheat_open (struct usb_serial_port *port, struct file *filp)
         if (retval)
                 goto exit;
 
-        port->tty->low_latency = 1;
+        if (tty)
+                tty->low_latency = 1;
 
         /* send an open port command */
         retval = firm_open(port);
@@ -640,9 +642,11 @@ static int whiteheat_open (struct usb_serial_port *port, struct file *filp)
                 goto exit;
         }
 
-        old_term.c_cflag = ~port->tty->termios->c_cflag;
-        old_term.c_iflag = ~port->tty->termios->c_iflag;
-        whiteheat_set_termios(port, &old_term);
+        if (tty) {
+                old_term.c_cflag = ~tty->termios->c_cflag;
+                old_term.c_iflag = ~tty->termios->c_iflag;
+                whiteheat_set_termios(tty, port, &old_term);
+        }
 
         /* Work around HCD bugs */
         usb_clear_halt(port->serial->dev, port->read_urb->pipe);
@@ -663,7 +667,8 @@ exit:
 }
 
 
-static void whiteheat_close(struct usb_serial_port *port, struct file * filp)
+static void whiteheat_close(struct tty_struct *tty,
+                        struct usb_serial_port *port, struct file * filp)
 {
         struct whiteheat_private *info = usb_get_serial_port_data(port);
         struct whiteheat_urb_wrap *wrap;
@@ -681,7 +686,7 @@ static void whiteheat_close(struct usb_serial_port *port, struct file * filp)
         }
         mutex_unlock(&port->serial->disc_mutex);
 
-        port->tty->closing = 1;
+        tty->closing = 1;
 
 /*
  * Not currently in use; tty_wait_until_sent() calls
@@ -689,12 +694,12 @@ static void whiteheat_close(struct usb_serial_port *port, struct file * filp)
  * acquisition. This should be fixed at some point. Greg's been
  * notified.
         if ((filp->f_flags & (O_NDELAY | O_NONBLOCK)) == 0) {
-                tty_wait_until_sent(port->tty, CLOSING_DELAY);
+                tty_wait_until_sent(tty, CLOSING_DELAY);
         }
 */
 
-        tty_driver_flush_buffer(port->tty);
-        tty_ldisc_flush(port->tty);
+        tty_driver_flush_buffer(tty);
+        tty_ldisc_flush(tty);
 
         firm_report_tx_done(port);
 
@@ -728,11 +733,12 @@ static void whiteheat_close(struct usb_serial_port *port, struct file * filp)
 
         stop_command_port(port->serial);
 
-        port->tty->closing = 0;
+        tty->closing = 0;
 }
 
 
-static int whiteheat_write(struct usb_serial_port *port, const unsigned char *buf, int count)
+static int whiteheat_write(struct tty_struct *tty,
+        struct usb_serial_port *port, const unsigned char *buf, int count)
 {
         struct usb_serial *serial = port->serial;
         struct whiteheat_private *info = usb_get_serial_port_data(port);
@@ -791,8 +797,9 @@ static int whiteheat_write(struct usb_serial_port *port, const unsigned char *bu
 }
 
 
-static int whiteheat_write_room(struct usb_serial_port *port)
+static int whiteheat_write_room(struct tty_struct *tty)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct whiteheat_private *info = usb_get_serial_port_data(port);
         struct list_head *tmp;
         int room = 0;
@@ -811,8 +818,9 @@ static int whiteheat_write_room(struct usb_serial_port *port)
 }
 
 
-static int whiteheat_tiocmget (struct usb_serial_port *port, struct file *file)
+static int whiteheat_tiocmget (struct tty_struct *tty, struct file *file)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct whiteheat_private *info = usb_get_serial_port_data(port);
         unsigned int modem_signals = 0;
 
@@ -828,9 +836,10 @@ static int whiteheat_tiocmget (struct usb_serial_port *port, struct file *file)
 }
 
 
-static int whiteheat_tiocmset (struct usb_serial_port *port, struct file *file,
+static int whiteheat_tiocmset (struct tty_struct *tty, struct file *file,
                                unsigned int set, unsigned int clear)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct whiteheat_private *info = usb_get_serial_port_data(port);
 
         dbg("%s - port %d", __func__, port->number);
@@ -851,8 +860,9 @@ static int whiteheat_tiocmset (struct usb_serial_port *port, struct file *file,
 }
 
 
-static int whiteheat_ioctl (struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg)
+static int whiteheat_ioctl (struct tty_struct *tty, struct file * file, unsigned int cmd, unsigned long arg)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct serial_struct serstruct;
         void __user *user_arg = (void __user *)arg;
 
@@ -896,20 +906,21 @@ static int whiteheat_ioctl (struct usb_serial_port *port, struct file * file, un
 }
 
 
-static void whiteheat_set_termios(struct usb_serial_port *port, struct ktermios *old_termios)
+static void whiteheat_set_termios(struct tty_struct *tty, struct usb_serial_port *port, struct ktermios *old_termios)
 {
-        dbg("%s -port %d", __func__, port->number);
-        firm_setup_port(port);
+        firm_setup_port(tty);
 }
 
 
-static void whiteheat_break_ctl(struct usb_serial_port *port, int break_state) {
+static void whiteheat_break_ctl(struct tty_struct *tty, int break_state) {
+        struct usb_serial_port *port = tty->driver_data;
         firm_set_break(port, break_state);
 }
 
 
-static int whiteheat_chars_in_buffer(struct usb_serial_port *port)
+static int whiteheat_chars_in_buffer(struct tty_struct *tty)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct whiteheat_private *info = usb_get_serial_port_data(port);
         struct list_head *tmp;
         struct whiteheat_urb_wrap *wrap;
@@ -930,8 +941,9 @@ static int whiteheat_chars_in_buffer(struct usb_serial_port *port)
 }
 
 
-static void whiteheat_throttle (struct usb_serial_port *port)
+static void whiteheat_throttle (struct tty_struct *tty)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct whiteheat_private *info = usb_get_serial_port_data(port);
         unsigned long flags;
 
@@ -945,8 +957,9 @@ static void whiteheat_throttle (struct usb_serial_port *port)
 }
 
 
-static void whiteheat_unthrottle (struct usb_serial_port *port)
+static void whiteheat_unthrottle (struct tty_struct *tty)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct whiteheat_private *info = usb_get_serial_port_data(port);
         int actually_throttled;
         unsigned long flags;
@@ -1184,9 +1197,10 @@ static int firm_close(struct usb_serial_port *port) {
 }
 
 
-static int firm_setup_port(struct usb_serial_port *port) {
+static int firm_setup_port(struct tty_struct *tty) {
+        struct usb_serial_port *port = tty->driver_data;
         struct whiteheat_port_settings port_settings;
-        unsigned int cflag = port->tty->termios->c_cflag;
+        unsigned int cflag = tty->termios->c_cflag;
 
         port_settings.port = port->number + 1;
 
@@ -1235,22 +1249,22 @@ static int firm_setup_port(struct usb_serial_port *port) {
             (port_settings.hflow & WHITEHEAT_HFLOW_DTR) ? "DTR" : "");
         
         /* determine software flow control */
-        if (I_IXOFF(port->tty))
+        if (I_IXOFF(tty))
                 port_settings.sflow = WHITEHEAT_SFLOW_RXTX;
         else
                 port_settings.sflow = WHITEHEAT_SFLOW_NONE;
         dbg("%s - software flow control = %c", __func__, port_settings.sflow);
         
-        port_settings.xon = START_CHAR(port->tty);
-        port_settings.xoff = STOP_CHAR(port->tty);
+        port_settings.xon = START_CHAR(tty);
+        port_settings.xoff = STOP_CHAR(tty);
         dbg("%s - XON = %2x, XOFF = %2x", __func__, port_settings.xon, port_settings.xoff);
 
         /* get the baud rate wanted */
-        port_settings.baud = tty_get_baud_rate(port->tty);
+        port_settings.baud = tty_get_baud_rate(tty);
         dbg("%s - baud rate = %d", __func__, port_settings.baud);
 
         /* fixme: should set validated settings */
-        tty_encode_baud_rate(port->tty, port_settings.baud, port_settings.baud);
+        tty_encode_baud_rate(tty, port_settings.baud, port_settings.baud);
         /* handle any settings that aren't specified in the tty structure */
         port_settings.lloop = 0;
         
@@ -1426,7 +1440,7 @@ static void rx_data_softint(struct work_struct *work)
         struct whiteheat_private *info =
                 container_of(work, struct whiteheat_private, rx_work);
         struct usb_serial_port *port = info->port;
-        struct tty_struct *tty = port->tty;
+        struct tty_struct *tty = port->port.tty;
         struct whiteheat_urb_wrap *wrap;
         struct urb *urb;
         unsigned long flags;