diff options
Diffstat (limited to 'drivers/usb/serial/usb-serial.c')
| -rw-r--r-- | drivers/usb/serial/usb-serial.c | 104 |
1 files changed, 68 insertions, 36 deletions
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c index 2a70563bbee1..0a566eea49c0 100644 --- a/drivers/usb/serial/usb-serial.c +++ b/drivers/usb/serial/usb-serial.c @@ -137,22 +137,10 @@ static void destroy_serial(struct kref *kref) dbg("%s - %s", __func__, serial->type->description); - serial->type->shutdown(serial); - /* return the minor range that this device had */ if (serial->minor != SERIAL_TTY_NO_MINOR) return_serial(serial); - for (i = 0; i < serial->num_ports; ++i) - serial->port[i]->port.count = 0; - - /* the ports are cleaned up and released in port_release() */ - for (i = 0; i < serial->num_ports; ++i) - if (serial->port[i]->dev.parent != NULL) { - device_unregister(&serial->port[i]->dev); - serial->port[i] = NULL; - } - /* 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 */ @@ -187,7 +175,7 @@ static int serial_open (struct tty_struct *tty, struct file *filp) struct usb_serial *serial; struct usb_serial_port *port; unsigned int portNumber; - int retval; + int retval = 0; dbg("%s", __func__); @@ -198,21 +186,24 @@ static int serial_open (struct tty_struct *tty, struct file *filp) return -ENODEV; } + mutex_lock(&serial->disc_mutex); portNumber = tty->index - serial->minor; port = serial->port[portNumber]; - if (!port) { - retval = -ENODEV; - goto bailout_kref_put; - } - - if (port->serial->disconnected) { + if (!port || serial->disconnected) retval = -ENODEV; - goto bailout_kref_put; - } + 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); + if (retval) + goto bailout_serial_put; if (mutex_lock_interruptible(&port->mutex)) { retval = -ERESTARTSYS; - goto bailout_kref_put; + goto bailout_port_put; } ++port->port.count; @@ -232,14 +223,20 @@ static int serial_open (struct tty_struct *tty, struct file *filp) goto bailout_mutex_unlock; } - retval = usb_autopm_get_interface(serial->interface); + 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; + mutex_unlock(&serial->disc_mutex); } mutex_unlock(&port->mutex); @@ -248,13 +245,16 @@ static int serial_open (struct tty_struct *tty, struct file *filp) 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_kref_put: +bailout_port_put: + put_device(&port->dev); +bailout_serial_put: usb_serial_put(serial); return retval; } @@ -262,6 +262,9 @@ bailout_kref_put: static void serial_close(struct tty_struct *tty, struct file *filp) { struct usb_serial_port *port = tty->driver_data; + struct usb_serial *serial; + struct module *owner; + int count; if (!port) return; @@ -269,6 +272,8 @@ static void serial_close(struct tty_struct *tty, struct file *filp) dbg("%s - port %d", __func__, port->number); mutex_lock(&port->mutex); + serial = port->serial; + owner = serial->type->driver.owner; if (port->port.count == 0) { mutex_unlock(&port->mutex); @@ -281,7 +286,7 @@ static void serial_close(struct tty_struct *tty, struct file *filp) * this before we drop the port count. The call is protected * by the port mutex */ - port->serial->type->close(tty, port, filp); + serial->type->close(tty, port, filp); if (port->port.count == (port->console ? 2 : 1)) { struct tty_struct *tty = tty_port_tty_get(&port->port); @@ -295,17 +300,23 @@ static void serial_close(struct tty_struct *tty, struct file *filp) } } - if (port->port.count == 1) { - mutex_lock(&port->serial->disc_mutex); - if (!port->serial->disconnected) - usb_autopm_put_interface(port->serial->interface); - mutex_unlock(&port->serial->disc_mutex); - module_put(port->serial->type->driver.owner); - } --port->port.count; - + count = port->port.count; mutex_unlock(&port->mutex); - usb_serial_put(port->serial); + put_device(&port->dev); + + /* Mustn't dereference port any more */ + if (count == 0) { + 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 */ + if (count == 0) + module_put(owner); } static int serial_write(struct tty_struct *tty, const unsigned char *buf, @@ -549,7 +560,13 @@ static void kill_traffic(struct usb_serial_port *port) static void port_free(struct usb_serial_port *port) { + /* + * Stop all the traffic before cancelling the work, so that + * nobody will restart it by calling usb_serial_port_softint. + */ kill_traffic(port); + cancel_work_sync(&port->work); + usb_free_urb(port->read_urb); usb_free_urb(port->write_urb); usb_free_urb(port->interrupt_in_urb); @@ -558,7 +575,6 @@ static void port_free(struct usb_serial_port *port) kfree(port->bulk_out_buffer); kfree(port->interrupt_in_buffer); kfree(port->interrupt_out_buffer); - flush_scheduled_work(); /* port->work */ kfree(port); } @@ -1043,6 +1059,12 @@ void usb_serial_disconnect(struct usb_interface *interface) usb_set_intfdata(interface, NULL); /* must set a flag, to signal subdrivers */ serial->disconnected = 1; + mutex_unlock(&serial->disc_mutex); + + /* Unfortunately, many of the sub-drivers expect the port structures + * to exist when their shutdown method is called, so we have to go + * through this awkward two-step unregistration procedure. + */ for (i = 0; i < serial->num_ports; ++i) { port = serial->port[i]; if (port) { @@ -1052,11 +1074,21 @@ void usb_serial_disconnect(struct usb_interface *interface) tty_kref_put(tty); } kill_traffic(port); + cancel_work_sync(&port->work); + device_del(&port->dev); + } + } + serial->type->shutdown(serial); + for (i = 0; i < serial->num_ports; ++i) { + port = serial->port[i]; + if (port) { + put_device(&port->dev); + serial->port[i] = NULL; } } + /* let the last holder of this object * cause it to be cleaned up */ - mutex_unlock(&serial->disc_mutex); usb_serial_put(serial); dev_info(dev, "device disconnected\n"); } |