diff options
Diffstat (limited to 'drivers/usb/serial/usb-serial.c')
-rw-r--r-- | drivers/usb/serial/usb-serial.c | 406 |
1 files changed, 185 insertions, 221 deletions
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c index 99188c92068b..aa6b2ae951ae 100644 --- a/drivers/usb/serial/usb-serial.c +++ b/drivers/usb/serial/usb-serial.c @@ -35,6 +35,7 @@ #include <linux/serial.h> #include <linux/usb.h> #include <linux/usb/serial.h> +#include <linux/kfifo.h> #include "pl2303.h" /* @@ -43,8 +44,6 @@ #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 +67,11 @@ 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 +79,15 @@ 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 +136,10 @@ 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) @@ -145,244 +158,222 @@ 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_cleanup(). + */ +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; - ++port->port.count; + mutex_unlock(&serial->disc_mutex); + + /* 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 + * serial_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. - * - * 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; - mutex_lock(&port->mutex); - serial = port->serial; - owner = serial->type->driver.owner; + /* 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); if (drv->close) drv->close(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_cleanup - 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 asynchronously after the last tty kref is dropped, + * and the tty layer has already done the tty_shutdown(tty); + */ +static void serial_cleanup(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); + + 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 +518,7 @@ 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 +588,6 @@ 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 +607,12 @@ 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. @@ -636,6 +624,8 @@ static void port_free(struct usb_serial_port *port) usb_free_urb(port->write_urb); usb_free_urb(port->interrupt_in_urb); usb_free_urb(port->interrupt_out_urb); + if (!IS_ERR(port->write_fifo) && port->write_fifo) + kfifo_free(port->write_fifo); kfree(port->bulk_in_buffer); kfree(port->bulk_out_buffer); kfree(port->interrupt_in_buffer); @@ -935,6 +925,11 @@ 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 */ @@ -970,6 +965,10 @@ int usb_serial_probe(struct usb_interface *interface, dev_err(&interface->dev, "No free urbs available\n"); goto probe_error; } + port->write_fifo = kfifo_alloc(PAGE_SIZE, GFP_KERNEL, + &port->lock); + if (IS_ERR(port->write_fifo)) + goto probe_error; buffer_size = le16_to_cpu(endpoint->wMaxPacketSize); port->bulk_out_size = buffer_size; port->bulk_out_endpointAddress = endpoint->bEndpointAddress; @@ -1077,15 +1076,10 @@ 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 +1097,7 @@ 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 +1123,7 @@ 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 +1148,7 @@ 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"); } @@ -1204,15 +1162,19 @@ int usb_serial_suspend(struct usb_interface *intf, pm_message_t message) serial->suspending = 1; + if (serial->type->suspend) { + r = serial->type->suspend(serial, message); + if (r < 0) + goto err_out; + } + for (i = 0; i < serial->num_ports; ++i) { port = serial->port[i]; if (port) kill_traffic(port); } - if (serial->type->suspend) - r = serial->type->suspend(serial, message); - +err_out: return r; } EXPORT_SYMBOL(usb_serial_suspend); @@ -1246,6 +1208,8 @@ static const struct tty_operations serial_ops = { .chars_in_buffer = serial_chars_in_buffer, .tiocmget = serial_tiocmget, .tiocmset = serial_tiocmset, + .cleanup = serial_cleanup, + .install = serial_install, .proc_fops = &serial_proc_fops, }; |