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Commit c706ebdf authored by Alan Stern's avatar Alan Stern Committed by Greg Kroah-Hartman
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USB: usb-serial: call port_probe and port_remove at the right times 



This patch (as1253) prevents the usb-serial core from calling a
driver's port_probe and port_remove methods more than once per port.
It also removes some unnecessary try_module_get() calls and adds a
missing port_remove method call in a failure path.

Signed-off-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent c6994e6f

drivers/usb/serial/bus.c

+11 −16
Original line number Diff line number Diff line
@@ -59,23 +59,22 @@ static int usb_serial_device_probe(struct device *dev) 
		retval = -ENODEV;

		goto exit;

	}

	if (port->dev_state != PORT_REGISTERING)

		goto exit;



	driver = port->serial->type;

	if (driver->port_probe) {

		if (!try_module_get(driver->driver.owner)) {

			dev_err(dev, "module get failed, exiting\n");

			retval = -EIO;

			goto exit;

		}

		retval = driver->port_probe(port);

		module_put(driver->driver.owner);

		if (retval)

			goto exit;

	}



	retval = device_create_file(dev, &dev_attr_port_number);

	if (retval)

	if (retval) {

		if (driver->port_remove)

			retval = driver->port_remove(port);

		goto exit;

	}



	minor = port->number;

	tty_register_device(usb_serial_tty_driver, minor, dev);
@@ -98,19 +97,15 @@ static int usb_serial_device_remove(struct device *dev) 
	if (!port)

		return -ENODEV;



	if (port->dev_state != PORT_UNREGISTERING)

		return retval;



	device_remove_file(&port->dev, &dev_attr_port_number);



	driver = port->serial->type;

	if (driver->port_remove) {

		if (!try_module_get(driver->driver.owner)) {

			dev_err(dev, "module get failed, exiting\n");

			retval = -EIO;

			goto exit;

		}

	if (driver->port_remove)

		retval = driver->port_remove(port);

		module_put(driver->driver.owner);

	}

exit:



	minor = port->number;

	tty_unregister_device(usb_serial_tty_driver, minor);

	dev_info(dev, "%s converter now disconnected from ttyUSB%d\n",

drivers/usb/serial/usb-serial.c

+22 −2
Original line number Diff line number Diff line
@@ -1046,10 +1046,15 @@ int usb_serial_probe(struct usb_interface *interface, 


		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);

		if (retval)

		if (retval) {

			dev_err(&port->dev, "Error registering port device, "

				"continuing\n");

			port->dev_state = PORT_UNREGISTERED;

		} else {

			port->dev_state = PORT_REGISTERED;

		}

	}



	usb_serial_console_init(debug, minor);
@@ -1130,7 +1135,22 @@ void usb_serial_disconnect(struct usb_interface *interface) 
			}

			kill_traffic(port);

			cancel_work_sync(&port->work);

			if (port->dev_state == PORT_REGISTERED) {



				/* Make sure the port is bound so that the

				 * driver's port_remove method is called.

				 */

				if (!port->dev.driver) {

					int rc;



					port->dev.driver =

							&serial->type->driver;

					rc = device_bind_driver(&port->dev);

				}

				port->dev_state = PORT_UNREGISTERING;

				device_del(&port->dev);

				port->dev_state = PORT_UNREGISTERED;

			}

		}

	}

	serial->type->shutdown(serial);

include/linux/usb/serial.h

+8 −0
Original line number Diff line number Diff line
@@ -27,6 +27,13 @@ 
/* parity check flag */

#define RELEVANT_IFLAG(iflag)	(iflag & (IGNBRK|BRKINT|IGNPAR|PARMRK|INPCK))



enum port_dev_state {

	PORT_UNREGISTERED,

	PORT_REGISTERING,

	PORT_REGISTERED,

	PORT_UNREGISTERING,

};



/**

 * usb_serial_port: structure for the specific ports of a device.

 * @serial: pointer back to the struct usb_serial owner of this port.
@@ -102,6 +109,7 @@ struct usb_serial_port { 
	char			console;

	unsigned long		sysrq; /* sysrq timeout */

	struct device		dev;

	enum port_dev_state	dev_state;

};

#define to_usb_serial_port(d) container_of(d, struct usb_serial_port, dev)