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, 44 insertions, 36 deletions

diff --git a/drivers/usb/serial/kobil_sct.c b/drivers/usb/serial/kobil_sct.c
index 693f00da7c03..40c67f0096b1 100644
--- a/drivers/usb/serial/kobil_sct.c
+++ b/drivers/usb/serial/kobil_sct.c
@@ -70,19 +70,22 @@ static int debug;
 /* Function prototypes */
 static int  kobil_startup (struct usb_serial *serial);
 static void kobil_shutdown (struct usb_serial *serial);
-static int  kobil_open (struct usb_serial_port *port, struct file *filp);
-static void kobil_close (struct usb_serial_port *port, struct file *filp);
-static int  kobil_write (struct usb_serial_port *port, 
+static int  kobil_open (struct tty_struct *tty,
+                        struct usb_serial_port *port, struct file *filp);
+static void kobil_close (struct tty_struct *tty, struct usb_serial_port *port,
+                        struct file *filp);
+static int  kobil_write (struct tty_struct *tty, struct usb_serial_port *port, 
                          const unsigned char *buf, int count);
-static int  kobil_write_room(struct usb_serial_port *port);
-static int  kobil_ioctl(struct usb_serial_port *port, struct file *file,
+static int  kobil_write_room(struct tty_struct *tty);
+static int  kobil_ioctl(struct tty_struct *tty, struct file *file,
                         unsigned int cmd, unsigned long arg);
-static int  kobil_tiocmget(struct usb_serial_port *port, struct file *file);
-static int  kobil_tiocmset(struct usb_serial_port *port, struct file *file,
+static int  kobil_tiocmget(struct tty_struct *tty, struct file *file);
+static int  kobil_tiocmset(struct tty_struct *tty, struct file *file,
                            unsigned int set, unsigned int clear);
 static void kobil_read_int_callback( struct urb *urb );
 static void kobil_write_callback( struct urb *purb );
-static void kobil_set_termios(struct usb_serial_port *port, struct ktermios *old);
+static void kobil_set_termios(struct tty_struct *tty, 
+                        struct usb_serial_port *port, struct ktermios *old);
 
 
 static struct usb_device_id id_table [] = {
@@ -201,8 +204,8 @@ static void kobil_shutdown (struct usb_serial *serial)
         dbg("%s - port %d", __func__, serial->port[0]->number);
 
         for (i=0; i < serial->num_ports; ++i) {
-                while (serial->port[i]->open_count > 0) {
-                        kobil_close (serial->port[i], NULL);
+                while (serial->port[i]->port.count > 0) {
+                        kobil_close (NULL, serial->port[i], NULL);
                 }
                 kfree(usb_get_serial_port_data(serial->port[i]));
                 usb_set_serial_port_data(serial->port[i], NULL);
@@ -210,7 +213,8 @@ static void kobil_shutdown (struct usb_serial *serial)
 }
 
 
-static int kobil_open (struct usb_serial_port *port, struct file *filp)
+static int kobil_open(struct tty_struct *tty,
+                        struct usb_serial_port *port, struct file *filp)
 {
         int result = 0;
         struct kobil_private *priv;
@@ -229,14 +233,15 @@ static int kobil_open (struct usb_serial_port *port, struct file *filp)
          * the data through, otherwise it is scheduled, and with high
          * data rates (like with OHCI) data can get lost.
          */
-        port->tty->low_latency = 1;
-
-        // without this, every push_tty_char is echoed :-(  
-        port->tty->termios->c_lflag = 0;
-        port->tty->termios->c_lflag &= ~(ISIG | ICANON | ECHO | IEXTEN | XCASE);
-        port->tty->termios->c_iflag = IGNBRK | IGNPAR | IXOFF;
-        port->tty->termios->c_oflag &= ~ONLCR; // do NOT translate CR to CR-NL (0x0A -> 0x0A 0x0D)
-        
+        if (tty) {
+                tty->low_latency = 1;
+
+                /* Default to echo off and other sane device settings */
+                tty->termios->c_lflag = 0;
+                tty->termios->c_lflag &= ~(ISIG | ICANON | ECHO | IEXTEN | XCASE);
+                tty->termios->c_iflag = IGNBRK | IGNPAR | IXOFF;
+                tty->termios->c_oflag &= ~ONLCR; // do NOT translate CR to CR-NL (0x0A -> 0x0A 0x0D)
+        }       
         // allocate memory for transfer buffer
         transfer_buffer = kzalloc(transfer_buffer_length, GFP_KERNEL);
         if (! transfer_buffer) {
@@ -330,7 +335,8 @@ static int kobil_open (struct usb_serial_port *port, struct file *filp)
 }
 
 
-static void kobil_close (struct usb_serial_port *port, struct file *filp)
+static void kobil_close(struct tty_struct *tty,
+                        struct usb_serial_port *port, struct file *filp)
 {
         dbg("%s - port %d", __func__, port->number);
 
@@ -360,7 +366,7 @@ static void kobil_read_int_callback(struct urb *urb)
                 return;
         }
 
-        tty = port->tty;
+        tty = port->port.tty;
         if (urb->actual_length) {
 
                 // BEGIN DEBUG
@@ -395,7 +401,7 @@ static void kobil_write_callback( struct urb *purb )
 }
 
 
-static int kobil_write (struct usb_serial_port *port, 
+static int kobil_write (struct tty_struct *tty, struct usb_serial_port *port, 
                         const unsigned char *buf, int count)
 {
         int length = 0;
@@ -417,12 +423,9 @@ static int kobil_write (struct usb_serial_port *port,
 
         // Copy data to buffer
         memcpy (priv->buf + priv->filled, buf, count);
-
         usb_serial_debug_data(debug, &port->dev, __func__, count, priv->buf + priv->filled);
-
         priv->filled = priv->filled + count;
 
-
         // only send complete block. TWIN, KAAN SIM and adapter K use the same protocol.
         if ( ((priv->device_type != KOBIL_ADAPTER_B_PRODUCT_ID) && (priv->filled > 2) && (priv->filled >= (priv->buf[1] + 3))) || 
              ((priv->device_type == KOBIL_ADAPTER_B_PRODUCT_ID) && (priv->filled > 3) && (priv->filled >= (priv->buf[2] + 4))) ) {
@@ -478,15 +481,17 @@ static int kobil_write (struct usb_serial_port *port,
 }
 
 
-static int kobil_write_room (struct usb_serial_port *port)
+static int kobil_write_room (struct tty_struct *tty)
 {
         //dbg("%s - port %d", __func__, port->number);
+        /* FIXME */
         return 8;
 }
 
 
-static int kobil_tiocmget(struct usb_serial_port *port, struct file *file)
+static int kobil_tiocmget(struct tty_struct *tty, struct file *file)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct kobil_private * priv;
         int result;
         unsigned char *transfer_buffer;
@@ -524,9 +529,10 @@ static int kobil_tiocmget(struct usb_serial_port *port, struct file *file)
         return result;
 }
 
-static int  kobil_tiocmset(struct usb_serial_port *port, struct file *file,
+static int kobil_tiocmset(struct tty_struct *tty, struct file *file,
                            unsigned int set, unsigned int clear)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct kobil_private * priv;
         int result;
         int dtr = 0;
@@ -590,12 +596,13 @@ static int  kobil_tiocmset(struct usb_serial_port *port, struct file *file,
         return (result < 0) ? result : 0;
 }
 
-static void kobil_set_termios(struct usb_serial_port *port, struct ktermios *old)
+static void kobil_set_termios(struct tty_struct *tty,
+                        struct usb_serial_port *port, struct ktermios *old)
 {
         struct kobil_private * priv;
         int result;
         unsigned short urb_val = 0;
-        int c_cflag = port->tty->termios->c_cflag;
+        int c_cflag = tty->termios->c_cflag;
         speed_t speed;
         void * settings;
 
@@ -604,7 +611,7 @@ static void kobil_set_termios(struct usb_serial_port *port, struct ktermios *old
                 // This device doesn't support ioctl calls
                 return;
 
-        switch (speed = tty_get_baud_rate(port->tty)) {
+        switch (speed = tty_get_baud_rate(tty)) {
                 case 1200:
                         urb_val = SUSBCR_SBR_1200;
                         break;
@@ -634,8 +641,8 @@ static void kobil_set_termios(struct usb_serial_port *port, struct ktermios *old
                 urb_val |= SUSBCR_SPASB_NoParity;
                 strcat(settings, "No Parity");
         }
-        port->tty->termios->c_cflag &= ~CMSPAR;
-        tty_encode_baud_rate(port->tty, speed, speed);
+        tty->termios->c_cflag &= ~CMSPAR;
+        tty_encode_baud_rate(tty, speed, speed);
 
         result = usb_control_msg( port->serial->dev,
                                   usb_rcvctrlpipe(port->serial->dev, 0 ),
@@ -650,8 +657,9 @@ static void kobil_set_termios(struct usb_serial_port *port, struct ktermios *old
         kfree(settings);
 }
 
-static int kobil_ioctl(struct usb_serial_port *port, struct file * file, unsigned int cmd, unsigned long arg)
+static int kobil_ioctl(struct tty_struct *tty, struct file * file, unsigned int cmd, unsigned long arg)
 {
+        struct usb_serial_port *port = tty->driver_data;
         struct kobil_private * priv = usb_get_serial_port_data(port);
         unsigned char *transfer_buffer;
         int transfer_buffer_length = 8;
@@ -662,7 +670,7 @@ static int kobil_ioctl(struct usb_serial_port *port, struct file * file, unsigne
                 return 0;
 
         switch (cmd) {
-        case TCFLSH:   // 0x540B
+        case TCFLSH:
                 transfer_buffer = kmalloc(transfer_buffer_length, GFP_KERNEL);
                 if (! transfer_buffer)
                         return -ENOBUFS;
@@ -680,7 +688,7 @@ static int kobil_ioctl(struct usb_serial_port *port, struct file * file, unsigne
                 
                 dbg("%s - port %d Send reset_all_queues (FLUSH) URB returns: %i", __func__, port->number, result);
                 kfree(transfer_buffer);
-                return (result < 0) ? -EFAULT : 0;
+                return (result < 0) ? -EIO: 0;
         default:
                 return -ENOIOCTLCMD;
         }