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, 37 insertions, 32 deletions

diff --git a/drivers/usb/serial/spcp8x5.c b/drivers/usb/serial/spcp8x5.c
index 55b2570b8b8b..58495f5cca1f 100644
--- a/drivers/usb/serial/spcp8x5.c
+++ b/drivers/usb/serial/spcp8x5.c
@@ -448,7 +448,8 @@ static void spcp8x5_set_workMode(struct usb_device *dev, u16 value,
 
 /* close the serial port. We should wait for data sending to device 1st and
  * then kill all urb. */
-static void spcp8x5_close(struct usb_serial_port *port, struct file *filp)
+static void spcp8x5_close(struct tty_struct *tty,
+                        struct usb_serial_port *port, struct file *filp)
 {
         struct spcp8x5_private *priv = usb_get_serial_port_data(port);
         unsigned long flags;
@@ -464,7 +465,7 @@ static void spcp8x5_close(struct usb_serial_port *port, struct file *filp)
         spin_lock_irqsave(&priv->lock, flags);
         timeout = SPCP8x5_CLOSING_WAIT;
         init_waitqueue_entry(&wait, current);
-        add_wait_queue(&port->tty->write_wait, &wait);
+        add_wait_queue(&tty->write_wait, &wait);
         for (;;) {
                 set_current_state(TASK_INTERRUPTIBLE);
                 if (ringbuf_avail_data(priv->buf) == 0 ||
@@ -475,7 +476,7 @@ static void spcp8x5_close(struct usb_serial_port *port, struct file *filp)
                 spin_lock_irqsave(&priv->lock, flags);
         }
         set_current_state(TASK_RUNNING);
-        remove_wait_queue(&port->tty->write_wait, &wait);
+        remove_wait_queue(&tty->write_wait, &wait);
 
         /* clear out any remaining data in the buffer */
         clear_ringbuf(priv->buf);
@@ -486,7 +487,7 @@ static void spcp8x5_close(struct usb_serial_port *port, struct file *filp)
          * flow control for data rates of 1200 bps or more, for lower rates we
          * should really know how much data is in the buffer to compute a delay
          * that is not unnecessarily long) */
-        bps = tty_get_baud_rate(port->tty);
+        bps = tty_get_baud_rate(tty);
         if (bps > 1200)
                 timeout = max((HZ*2560) / bps, HZ/10);
         else
@@ -495,8 +496,8 @@ static void spcp8x5_close(struct usb_serial_port *port, struct file *filp)
         schedule_timeout(timeout);
 
         /* clear control lines */
-        if (port->tty) {
-                c_cflag = port->tty->termios->c_cflag;
+        if (tty) {
+                c_cflag = tty->termios->c_cflag;
                 if (c_cflag & HUPCL) {
                         spin_lock_irqsave(&priv->lock, flags);
                         priv->line_control = 0;
@@ -518,14 +519,14 @@ static void spcp8x5_close(struct usb_serial_port *port, struct file *filp)
 }
 
 /* set the serial param for transfer. we should check if we really need to
- * transfer. then if be set flow contorl we should do this too. */
-static void spcp8x5_set_termios(struct usb_serial_port *port,
-                                struct ktermios *old_termios)
+ * transfer. if we set flow control we should do this too. */
+static void spcp8x5_set_termios(struct tty_struct *tty,
+                struct usb_serial_port *port, struct ktermios *old_termios)
 {
         struct usb_serial *serial = port->serial;
         struct spcp8x5_private *priv = usb_get_serial_port_data(port);
         unsigned long flags;
-        unsigned int cflag = port->tty->termios->c_cflag;
+        unsigned int cflag = tty->termios->c_cflag;
         unsigned int old_cflag = old_termios->c_cflag;
         unsigned short uartdata;
         unsigned char buf[2] = {0, 0};
@@ -533,21 +534,19 @@ static void spcp8x5_set_termios(struct usb_serial_port *port,
         int i;
         u8 control;
 
-        if ((!port->tty) || (!port->tty->termios))
-                return;
-
         /* for the 1st time call this function */
         spin_lock_irqsave(&priv->lock, flags);
         if (!priv->termios_initialized) {
-                *(port->tty->termios) = tty_std_termios;
-                port->tty->termios->c_cflag = B115200 | CS8 | CREAD |
-                                              HUPCL | CLOCAL;
+                *(tty->termios) = tty_std_termios;
+                tty->termios->c_cflag = B115200 | CS8 | CREAD | HUPCL | CLOCAL;
+                tty->termios->c_ispeed = 115200;
+                tty->termios->c_ospeed = 115200;
                 priv->termios_initialized = 1;
         }
         spin_unlock_irqrestore(&priv->lock, flags);
 
         /* check that they really want us to change something */
-        if (!tty_termios_hw_change(port->tty->termios, old_termios))
+        if (!tty_termios_hw_change(tty->termios, old_termios))
                 return;
 
         /* set DTR/RTS active */
@@ -567,7 +566,7 @@ static void spcp8x5_set_termios(struct usb_serial_port *port,
         }
 
         /* Set Baud Rate */
-        baud = tty_get_baud_rate(port->tty);;
+        baud = tty_get_baud_rate(tty);;
         switch (baud) {
         case 300:       buf[0] = 0x00;  break;
         case 600:       buf[0] = 0x01;  break;
@@ -643,7 +642,8 @@ static void spcp8x5_set_termios(struct usb_serial_port *port,
 
 /* open the serial port. do some usb system call. set termios and get the line
  * status of the device. then submit the read urb */
-static int spcp8x5_open(struct usb_serial_port *port, struct file *filp)
+static int spcp8x5_open(struct tty_struct *tty,
+                        struct usb_serial_port *port, struct file *filp)
 {
         struct ktermios tmp_termios;
         struct usb_serial *serial = port->serial;
@@ -665,7 +665,7 @@ static int spcp8x5_open(struct usb_serial_port *port, struct file *filp)
                 return ret;
 
         spin_lock_irqsave(&priv->lock, flags);
-        if (port->tty->termios->c_cflag & CBAUD)
+        if (tty && (tty->termios->c_cflag & CBAUD))
                 priv->line_control = MCR_DTR | MCR_RTS;
         else
                 priv->line_control = 0;
@@ -674,8 +674,8 @@ static int spcp8x5_open(struct usb_serial_port *port, struct file *filp)
         spcp8x5_set_ctrlLine(serial->dev, priv->line_control , priv->type);
 
         /* Setup termios */
-        if (port->tty)
-                spcp8x5_set_termios(port, &tmp_termios);
+        if (tty)
+                spcp8x5_set_termios(tty, port, &tmp_termios);
 
         spcp8x5_get_msr(serial->dev, &status, priv->type);
 
@@ -690,7 +690,7 @@ static int spcp8x5_open(struct usb_serial_port *port, struct file *filp)
         port->read_urb->dev = serial->dev;
         ret = usb_submit_urb(port->read_urb, GFP_KERNEL);
         if (ret) {
-                spcp8x5_close(port, NULL);
+                spcp8x5_close(tty, port, NULL);
                 return -EPROTO;
         }
         return 0;
@@ -717,7 +717,7 @@ static void spcp8x5_read_bulk_callback(struct urb *urb)
 
         /* check the urb status */
         if (urb->status) {
-                if (!port->open_count)
+                if (!port->port.count)
                         return;
                 if (urb->status == -EPROTO) {
                         /* spcp8x5 mysteriously fails with -EPROTO */
@@ -755,7 +755,7 @@ static void spcp8x5_read_bulk_callback(struct urb *urb)
                 tty_flag = TTY_FRAME;
         dev_dbg(&port->dev, "tty_flag = %d\n", tty_flag);
 
-        tty = port->tty;
+        tty = port->port.tty;
         if (tty && urb->actual_length) {
                 tty_buffer_request_room(tty, urb->actual_length + 1);
                 /* overrun is special, not associated with a char */
@@ -767,7 +767,7 @@ static void spcp8x5_read_bulk_callback(struct urb *urb)
         }
 
         /* Schedule the next read _if_ we are still open */
-        if (port->open_count) {
+        if (port->port.count) {
                 urb->dev = port->serial->dev;
                 result = usb_submit_urb(urb , GFP_ATOMIC);
                 if (result)
@@ -866,7 +866,7 @@ static void spcp8x5_write_bulk_callback(struct urb *urb)
 }
 
 /* write data to ring buffer. and then start the write transfer */
-static int spcp8x5_write(struct usb_serial_port *port,
+static int spcp8x5_write(struct tty_struct *tty, struct usb_serial_port *port,
                          const unsigned char *buf, int count)
 {
         struct spcp8x5_private *priv = usb_get_serial_port_data(port);
@@ -925,9 +925,10 @@ static int spcp8x5_wait_modem_info(struct usb_serial_port *port,
         return 0;
 }
 
-static int spcp8x5_ioctl(struct usb_serial_port *port, struct file *file,
+static int spcp8x5_ioctl(struct tty_struct *tty, struct file *file,
                          unsigned int cmd, unsigned long arg)
 {
+        struct usb_serial_port *port = tty->driver_data;
         dbg("%s (%d) cmd = 0x%04x", __func__, port->number, cmd);
 
         switch (cmd) {
@@ -943,9 +944,10 @@ static int spcp8x5_ioctl(struct usb_serial_port *port, struct file *file,
         return -ENOIOCTLCMD;
 }
 
-static int spcp8x5_tiocmset(struct usb_serial_port *port, struct file *file,
+static int spcp8x5_tiocmset(struct tty_struct *tty, struct file *file,
                             unsigned int set, unsigned int clear)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct spcp8x5_private *priv = usb_get_serial_port_data(port);
         unsigned long flags;
         u8 control;
@@ -965,8 +967,9 @@ static int spcp8x5_tiocmset(struct usb_serial_port *port, struct file *file,
         return spcp8x5_set_ctrlLine(port->serial->dev, control , priv->type);
 }
 
-static int spcp8x5_tiocmget(struct usb_serial_port *port, struct file *file)
+static int spcp8x5_tiocmget(struct tty_struct *tty, struct file *file)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct spcp8x5_private *priv = usb_get_serial_port_data(port);
         unsigned long flags;
         unsigned int mcr;
@@ -989,8 +992,9 @@ static int spcp8x5_tiocmget(struct usb_serial_port *port, struct file *file)
 }
 
 /* get the avail space room in ring buffer */
-static int spcp8x5_write_room(struct usb_serial_port *port)
+static int spcp8x5_write_room(struct tty_struct *tty)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct spcp8x5_private *priv = usb_get_serial_port_data(port);
         int room = 0;
         unsigned long flags;
@@ -1003,8 +1007,9 @@ static int spcp8x5_write_room(struct usb_serial_port *port)
 }
 
 /* get the number of avail data in write ring buffer */
-static int spcp8x5_chars_in_buffer(struct usb_serial_port *port)
+static int spcp8x5_chars_in_buffer(struct tty_struct *tty)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct spcp8x5_private *priv = usb_get_serial_port_data(port);
         int chars = 0;
         unsigned long flags;