1 files changed, 173 insertions, 212 deletions

diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 99188c92068b..9d7ca4868d37 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -43,8 +43,6 @@
 #define DRIVER_AUTHOR "Greg Kroah-Hartman, greg@kroah.com, http://www.kroah.com/linux/"
 #define DRIVER_DESC "USB Serial Driver core"
 
-static void port_free(struct usb_serial_port *port);
-
 /* Driver structure we register with the USB core */
 static struct usb_driver usb_serial_driver = {
         .name =         "usbserial",
@@ -68,6 +66,11 @@ static struct usb_serial *serial_table[SERIAL_TTY_MINORS];
 static DEFINE_MUTEX(table_lock);
 static LIST_HEAD(usb_serial_driver_list);
 
+/*
+ * Look up the serial structure.  If it is found and it hasn't been
+ * disconnected, return with its disc_mutex held and its refcount
+ * incremented.  Otherwise return NULL.
+ */
 struct usb_serial *usb_serial_get_by_index(unsigned index)
 {
         struct usb_serial *serial;
@@ -75,8 +78,15 @@ struct usb_serial *usb_serial_get_by_index(unsigned index)
         mutex_lock(&table_lock);
         serial = serial_table[index];
 
-        if (serial)
-                kref_get(&serial->kref);
+        if (serial) {
+                mutex_lock(&serial->disc_mutex);
+                if (serial->disconnected) {
+                        mutex_unlock(&serial->disc_mutex);
+                        serial = NULL;
+                } else {
+                        kref_get(&serial->kref);
+                }
+        }
         mutex_unlock(&table_lock);
         return serial;
 }
@@ -125,8 +135,10 @@ static void return_serial(struct usb_serial *serial)
 
         dbg("%s", __func__);
 
+        mutex_lock(&table_lock);
         for (i = 0; i < serial->num_ports; ++i)
                 serial_table[serial->minor + i] = NULL;
+        mutex_unlock(&table_lock);
 }
 
 static void destroy_serial(struct kref *kref)
@@ -145,161 +157,157 @@ static void destroy_serial(struct kref *kref)
 
         serial->type->release(serial);
 
-        for (i = 0; i < serial->num_ports; ++i) {
+        /* Now that nothing is using the ports, they can be freed */
+        for (i = 0; i < serial->num_port_pointers; ++i) {
                 port = serial->port[i];
-                if (port)
+                if (port) {
+                        port->serial = NULL;
                         put_device(&port->dev);
-        }
-
-        /* If this is a "fake" port, we have to clean it up here, as it will
-         * not get cleaned up in port_release() as it was never registered with
-         * the driver core */
-        if (serial->num_ports < serial->num_port_pointers) {
-                for (i = serial->num_ports;
-                                        i < serial->num_port_pointers; ++i) {
-                        port = serial->port[i];
-                        if (port)
-                                port_free(port);
                 }
         }
 
         usb_put_dev(serial->dev);
-
-        /* free up any memory that we allocated */
         kfree(serial);
 }
 
 void usb_serial_put(struct usb_serial *serial)
 {
-        mutex_lock(&table_lock);
         kref_put(&serial->kref, destroy_serial);
-        mutex_unlock(&table_lock);
 }
 
 /*****************************************************************************
  * Driver tty interface functions
  *****************************************************************************/
-static int serial_open (struct tty_struct *tty, struct file *filp)
+
+/**
+ * serial_install - install tty
+ * @driver: the driver (USB in our case)
+ * @tty: the tty being created
+ *
+ * Create the termios objects for this tty.  We use the default
+ * USB serial settings but permit them to be overridden by
+ * serial->type->init_termios.
+ *
+ * This is the first place a new tty gets used.  Hence this is where we
+ * acquire references to the usb_serial structure and the driver module,
+ * where we store a pointer to the port, and where we do an autoresume.
+ * All these actions are reversed in serial_release().
+ */
+static int serial_install(struct tty_driver *driver, struct tty_struct *tty)
 {
+        int idx = tty->index;
         struct usb_serial *serial;
         struct usb_serial_port *port;
-        unsigned int portNumber;
-        int retval = 0;
-        int first = 0;
+        int retval = -ENODEV;
 
         dbg("%s", __func__);
 
-        /* get the serial object associated with this tty pointer */
-        serial = usb_serial_get_by_index(tty->index);
-        if (!serial) {
-                tty->driver_data = NULL;
-                return -ENODEV;
-        }
+        serial = usb_serial_get_by_index(idx);
+        if (!serial)
+                return retval;
 
-        mutex_lock(&serial->disc_mutex);
-        portNumber = tty->index - serial->minor;
-        port = serial->port[portNumber];
-        if (!port || serial->disconnected)
-                retval = -ENODEV;
-        else
-                get_device(&port->dev);
-        /*
-         * Note: Our locking order requirement does not allow port->mutex
-         * to be acquired while serial->disc_mutex is held.
-         */
-        mutex_unlock(&serial->disc_mutex);
+        port = serial->port[idx - serial->minor];
+        if (!port)
+                goto error_no_port;
+        if (!try_module_get(serial->type->driver.owner))
+                goto error_module_get;
+
+        /* perform the standard setup */
+        retval = tty_init_termios(tty);
         if (retval)
-                goto bailout_serial_put;
+                goto error_init_termios;
 
-        if (mutex_lock_interruptible(&port->mutex)) {
-                retval = -ERESTARTSYS;
-                goto bailout_port_put;
-        }
+        retval = usb_autopm_get_interface(serial->interface);
+        if (retval)
+                goto error_get_interface;
+
+        mutex_unlock(&serial->disc_mutex);
 
-        ++port->port.count;
+        /* allow the driver to update the settings */
+        if (serial->type->init_termios)
+                serial->type->init_termios(tty);
 
-        /* set up our port structure making the tty driver
-         * remember our port object, and us it */
         tty->driver_data = port;
-        tty_port_tty_set(&port->port, tty);
 
-        /* If the console is attached, the device is already open */
-        if (port->port.count == 1 && !port->console) {
-                first = 1;
-                /* lock this module before we call it
-                 * this may fail, which means we must bail out,
-                 * safe because we are called with BKL held */
-                if (!try_module_get(serial->type->driver.owner)) {
-                        retval = -ENODEV;
-                        goto bailout_mutex_unlock;
-                }
+        /* Final install (we use the default method) */
+        tty_driver_kref_get(driver);
+        tty->count++;
+        driver->ttys[idx] = tty;
+        return retval;
 
+ error_get_interface:
+ error_init_termios:
+        module_put(serial->type->driver.owner);
+ error_module_get:
+ error_no_port:
+        usb_serial_put(serial);
+        mutex_unlock(&serial->disc_mutex);
+        return retval;
+}
+
+static int serial_open(struct tty_struct *tty, struct file *filp)
+{
+        struct usb_serial_port *port = tty->driver_data;
+        struct usb_serial *serial = port->serial;
+        int retval;
+
+        dbg("%s - port %d", __func__, port->number);
+
+        spin_lock_irq(&port->port.lock);
+        if (!tty_hung_up_p(filp))
+                ++port->port.count;
+        spin_unlock_irq(&port->port.lock);
+        tty_port_tty_set(&port->port, tty);
+
+        /* Do the device-specific open only if the hardware isn't
+         * already initialized.
+         */
+        if (!test_bit(ASYNCB_INITIALIZED, &port->port.flags)) {
+                if (mutex_lock_interruptible(&port->mutex))
+                        return -ERESTARTSYS;
                 mutex_lock(&serial->disc_mutex);
                 if (serial->disconnected)
                         retval = -ENODEV;
                 else
-                        retval = usb_autopm_get_interface(serial->interface);
-                if (retval)
-                        goto bailout_module_put;
-
-                /* only call the device specific open if this
-                 * is the first time the port is opened */
-                retval = serial->type->open(tty, port, filp);
-                if (retval)
-                        goto bailout_interface_put;
+                        retval = port->serial->type->open(tty, port);
                 mutex_unlock(&serial->disc_mutex);
+                mutex_unlock(&port->mutex);
+                if (retval)
+                        return retval;
                 set_bit(ASYNCB_INITIALIZED, &port->port.flags);
         }
-        mutex_unlock(&port->mutex);
+
         /* Now do the correct tty layer semantics */
         retval = tty_port_block_til_ready(&port->port, tty, filp);
-        if (retval == 0) {
-                if (!first)
-                        usb_serial_put(serial);
-                return 0;
-        }
-        mutex_lock(&port->mutex);
-        if (first == 0)
-                goto bailout_mutex_unlock;
-        /* Undo the initial port actions */
-        mutex_lock(&serial->disc_mutex);
-bailout_interface_put:
-        usb_autopm_put_interface(serial->interface);
-bailout_module_put:
-        mutex_unlock(&serial->disc_mutex);
-        module_put(serial->type->driver.owner);
-bailout_mutex_unlock:
-        port->port.count = 0;
-        tty->driver_data = NULL;
-        tty_port_tty_set(&port->port, NULL);
-        mutex_unlock(&port->mutex);
-bailout_port_put:
-        put_device(&port->dev);
-bailout_serial_put:
-        usb_serial_put(serial);
         return retval;
 }
 
 /**
- *      serial_do_down          -       shut down hardware
- *      @port: port to shut down
- *
- *      Shut down a USB port unless it is the console. We never shut down the
- *      console hardware as it will always be in use.
+ * serial_down - shut down hardware
+ * @port: port to shut down
  *
- *      Don't free any resources at this point
+ * Shut down a USB serial port unless it is the console.  We never
+ * shut down the console hardware as it will always be in use.
  */
-static void serial_do_down(struct usb_serial_port *port)
+static void serial_down(struct usb_serial_port *port)
 {
         struct usb_serial_driver *drv = port->serial->type;
         struct usb_serial *serial;
         struct module *owner;
 
-        /* The console is magical, do not hang up the console hardware
-           or there will be tears */
+        /*
+         * The console is magical.  Do not hang up the console hardware
+         * or there will be tears.
+         */
         if (port->console)
                 return;
 
+        /* Don't call the close method if the hardware hasn't been
+         * initialized.
+         */
+        if (!test_and_clear_bit(ASYNCB_INITIALIZED, &port->port.flags))
+                return;
+
         mutex_lock(&port->mutex);
         serial = port->serial;
         owner = serial->type->driver.owner;
@@ -310,79 +318,69 @@ static void serial_do_down(struct usb_serial_port *port)
         mutex_unlock(&port->mutex);
 }
 
-/**
- *      serial_do_free          -       free resources post close/hangup
- *      @port: port to free up
- *
- *      Do the resource freeing and refcount dropping for the port. We must
- *      be careful about ordering and we must avoid freeing up the console.
- */
-
-static void serial_do_free(struct usb_serial_port *port)
+static void serial_hangup(struct tty_struct *tty)
 {
-        struct usb_serial *serial;
-        struct module *owner;
+        struct usb_serial_port *port = tty->driver_data;
 
-        /* The console is magical, do not hang up the console hardware
-           or there will be tears */
-        if (port->console)
-                return;
+        dbg("%s - port %d", __func__, port->number);
 
-        serial = port->serial;
-        owner = serial->type->driver.owner;
-        put_device(&port->dev);
-        /* Mustn't dereference port any more */
-        mutex_lock(&serial->disc_mutex);
-        if (!serial->disconnected)
-                usb_autopm_put_interface(serial->interface);
-        mutex_unlock(&serial->disc_mutex);
-        usb_serial_put(serial);
-        /* Mustn't dereference serial any more */
-        module_put(owner);
+        serial_down(port);
+        tty_port_hangup(&port->port);
 }
 
 static void serial_close(struct tty_struct *tty, struct file *filp)
 {
         struct usb_serial_port *port = tty->driver_data;
 
-        if (!port)
-                return;
-
         dbg("%s - port %d", __func__, port->number);
 
-        /* FIXME:
-           This leaves a very narrow race. Really we should do the
-           serial_do_free() on tty->shutdown(), but tty->shutdown can
-           be called from IRQ context and serial_do_free can sleep.
-
-           The right fix is probably to make the tty free (which is rare)
-           and thus tty->shutdown() occur via a work queue and simplify all
-           the drivers that use it.
-        */
-        if (tty_hung_up_p(filp)) {
-                /* serial_hangup already called serial_down at this point.
-                   Another user may have already reopened the port but
-                   serial_do_free is refcounted */
-                serial_do_free(port);
+        if (tty_hung_up_p(filp))
                 return;
-        }
-
         if (tty_port_close_start(&port->port, tty, filp) == 0)
                 return;
-
-        serial_do_down(port);           
+        serial_down(port);
         tty_port_close_end(&port->port, tty);
         tty_port_tty_set(&port->port, NULL);
-        serial_do_free(port);
 }
 
-static void serial_hangup(struct tty_struct *tty)
+/**
+ * serial_release - free resources post close/hangup
+ * @port: port to free up
+ *
+ * Do the resource freeing and refcount dropping for the port.
+ * Avoid freeing the console.
+ *
+ * Called when the last tty kref is dropped.
+ */
+static void serial_release(struct tty_struct *tty)
 {
         struct usb_serial_port *port = tty->driver_data;
-        serial_do_down(port);
-        tty_port_hangup(&port->port);
-        /* We must not free port yet - the USB serial layer depends on it's
-           continued existence */
+        struct usb_serial *serial;
+        struct module *owner;
+
+        /* The console is magical.  Do not hang up the console hardware
+         * or there will be tears.
+         */
+        if (port->console)
+                return;
+
+        dbg("%s - port %d", __func__, port->number);
+
+        /* Standard shutdown processing */
+        tty_shutdown(tty);
+
+        tty->driver_data = NULL;
+
+        serial = port->serial;
+        owner = serial->type->driver.owner;
+
+        mutex_lock(&serial->disc_mutex);
+        if (!serial->disconnected)
+                usb_autopm_put_interface(serial->interface);
+        mutex_unlock(&serial->disc_mutex);
+
+        usb_serial_put(serial);
+        module_put(owner);
 }
 
 static int serial_write(struct tty_struct *tty, const unsigned char *buf,
@@ -527,6 +525,7 @@ static int serial_proc_show(struct seq_file *m, void *v)
 
                 seq_putc(m, '\n');
                 usb_serial_put(serial);
+                mutex_unlock(&serial->disc_mutex);
         }
         return 0;
 }
@@ -596,14 +595,6 @@ static void usb_serial_port_work(struct work_struct *work)
         tty_kref_put(tty);
 }
 
-static void port_release(struct device *dev)
-{
-        struct usb_serial_port *port = to_usb_serial_port(dev);
-
-        dbg ("%s - %s", __func__, dev_name(dev));
-        port_free(port);
-}
-
 static void kill_traffic(struct usb_serial_port *port)
 {
         usb_kill_urb(port->read_urb);
@@ -623,8 +614,12 @@ static void kill_traffic(struct usb_serial_port *port)
         usb_kill_urb(port->interrupt_out_urb);
 }
 
-static void port_free(struct usb_serial_port *port)
+static void port_release(struct device *dev)
 {
+        struct usb_serial_port *port = to_usb_serial_port(dev);
+
+        dbg ("%s - %s", __func__, dev_name(dev));
+
         /*
          * Stop all the traffic before cancelling the work, so that
          * nobody will restart it by calling usb_serial_port_softint.
@@ -935,6 +930,11 @@ int usb_serial_probe(struct usb_interface *interface,
                 mutex_init(&port->mutex);
                 INIT_WORK(&port->work, usb_serial_port_work);
                 serial->port[i] = port;
+                port->dev.parent = &interface->dev;
+                port->dev.driver = NULL;
+                port->dev.bus = &usb_serial_bus_type;
+                port->dev.release = &port_release;
+                device_initialize(&port->dev);
         }
 
         /* set up the endpoint information */
@@ -1077,15 +1077,10 @@ int usb_serial_probe(struct usb_interface *interface,
         /* register all of the individual ports with the driver core */
         for (i = 0; i < num_ports; ++i) {
                 port = serial->port[i];
-                port->dev.parent = &interface->dev;
-                port->dev.driver = NULL;
-                port->dev.bus = &usb_serial_bus_type;
-                port->dev.release = &port_release;
-
                 dev_set_name(&port->dev, "ttyUSB%d", port->number);
                 dbg ("%s - registering %s", __func__, dev_name(&port->dev));
                 port->dev_state = PORT_REGISTERING;
-                retval = device_register(&port->dev);
+                retval = device_add(&port->dev);
                 if (retval) {
                         dev_err(&port->dev, "Error registering port device, "
                                 "continuing\n");
@@ -1103,39 +1098,7 @@ exit:
         return 0;
 
 probe_error:
-        for (i = 0; i < num_bulk_in; ++i) {
-                port = serial->port[i];
-                if (!port)
-                        continue;
-                usb_free_urb(port->read_urb);
-                kfree(port->bulk_in_buffer);
-        }
-        for (i = 0; i < num_bulk_out; ++i) {
-                port = serial->port[i];
-                if (!port)
-                        continue;
-                usb_free_urb(port->write_urb);
-                kfree(port->bulk_out_buffer);
-        }
-        for (i = 0; i < num_interrupt_in; ++i) {
-                port = serial->port[i];
-                if (!port)
-                        continue;
-                usb_free_urb(port->interrupt_in_urb);
-                kfree(port->interrupt_in_buffer);
-        }
-        for (i = 0; i < num_interrupt_out; ++i) {
-                port = serial->port[i];
-                if (!port)
-                        continue;
-                usb_free_urb(port->interrupt_out_urb);
-                kfree(port->interrupt_out_buffer);
-        }
-
-        /* free up any memory that we allocated */
-        for (i = 0; i < serial->num_port_pointers; ++i)
-                kfree(serial->port[i]);
-        kfree(serial);
+        usb_serial_put(serial);
         return -EIO;
 }
 EXPORT_SYMBOL_GPL(usb_serial_probe);
@@ -1161,10 +1124,7 @@ void usb_serial_disconnect(struct usb_interface *interface)
                 if (port) {
                         struct tty_struct *tty = tty_port_tty_get(&port->port);
                         if (tty) {
-                                /* The hangup will occur asynchronously but
-                                   the object refcounts will sort out all the
-                                   cleanup */
-                                tty_hangup(tty);
+                                tty_vhangup(tty);
                                 tty_kref_put(tty);
                         }
                         kill_traffic(port);
@@ -1189,8 +1149,7 @@ void usb_serial_disconnect(struct usb_interface *interface)
         }
         serial->type->disconnect(serial);
 
-        /* let the last holder of this object
-         * cause it to be cleaned up */
+        /* let the last holder of this object cause it to be cleaned up */
         usb_serial_put(serial);
         dev_info(dev, "device disconnected\n");
 }
@@ -1246,6 +1205,8 @@ static const struct tty_operations serial_ops = {
         .chars_in_buffer =      serial_chars_in_buffer,
         .tiocmget =             serial_tiocmget,
         .tiocmset =             serial_tiocmset,
+        .shutdown =             serial_release,
+        .install =              serial_install,
         .proc_fops =            &serial_proc_fops,
 };