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Commit 6a5c821c authored by Johan Hovold's avatar Johan Hovold Committed by Greg Kroah-Hartman
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USB: serial: use urb poison to reliably kill traffic 



Use usb_poison_urb to reliably kill all urbs on disconnect and suspend.

This way there will be no question that the urbs cannot be resubmitted
by buggy subdrivers.

Signed-off-by: default avatarJohan Hovold <jhovold@gmail.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 68a2bed1

drivers/usb/serial/usb-serial.c

+37 −18
Original line number Diff line number Diff line
@@ -542,27 +542,30 @@ static void usb_serial_port_work(struct work_struct *work) 
	tty_kref_put(tty);

}



static void kill_traffic(struct usb_serial_port *port)

static void usb_serial_port_poison_urbs(struct usb_serial_port *port)

{

	int i;



	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)

		usb_kill_urb(port->read_urbs[i]);

		usb_poison_urb(port->read_urbs[i]);

	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)

		usb_kill_urb(port->write_urbs[i]);

	/*

	 * This is tricky.

	 * Some drivers submit the read_urb in the

	 * handler for the write_urb or vice versa

	 * this order determines the order in which

	 * usb_kill_urb() must be used to reliably

	 * kill the URBs. As it is unknown here,

	 * both orders must be used in turn.

	 * The call below is not redundant.

	 */

	usb_kill_urb(port->read_urb);

	usb_kill_urb(port->interrupt_in_urb);

	usb_kill_urb(port->interrupt_out_urb);

		usb_poison_urb(port->write_urbs[i]);



	usb_poison_urb(port->interrupt_in_urb);

	usb_poison_urb(port->interrupt_out_urb);

}



static void usb_serial_port_unpoison_urbs(struct usb_serial_port *port)

{

	int i;



	for (i = 0; i < ARRAY_SIZE(port->read_urbs); ++i)

		usb_unpoison_urb(port->read_urbs[i]);

	for (i = 0; i < ARRAY_SIZE(port->write_urbs); ++i)

		usb_unpoison_urb(port->write_urbs[i]);



	usb_unpoison_urb(port->interrupt_in_urb);

	usb_unpoison_urb(port->interrupt_out_urb);

}



static void usb_serial_port_release(struct device *dev)
@@ -1082,7 +1085,7 @@ static void usb_serial_disconnect(struct usb_interface *interface) 
				tty_vhangup(tty);

				tty_kref_put(tty);

			}

			kill_traffic(port);

			usb_serial_port_poison_urbs(port);

			cancel_work_sync(&port->work);

			if (device_is_registered(&port->dev))

				device_del(&port->dev);
@@ -1120,7 +1123,7 @@ int usb_serial_suspend(struct usb_interface *intf, pm_message_t message) 
	for (i = 0; i < serial->num_ports; ++i) {

		port = serial->port[i];

		if (port)

			kill_traffic(port);

			usb_serial_port_poison_urbs(port);

	}



err_out:
@@ -1128,11 +1131,25 @@ int usb_serial_suspend(struct usb_interface *intf, pm_message_t message) 
}

EXPORT_SYMBOL(usb_serial_suspend);



static void usb_serial_unpoison_port_urbs(struct usb_serial *serial)

{

	struct usb_serial_port *port;

	int i;



	for (i = 0; i < serial->num_ports; ++i) {

		port = serial->port[i];

		if (port)

			usb_serial_port_unpoison_urbs(port);

	}

}



int usb_serial_resume(struct usb_interface *intf)

{

	struct usb_serial *serial = usb_get_intfdata(intf);

	int rv;



	usb_serial_unpoison_port_urbs(serial);



	serial->suspending = 0;

	if (serial->type->resume)

		rv = serial->type->resume(serial);
@@ -1148,6 +1165,8 @@ static int usb_serial_reset_resume(struct usb_interface *intf) 
	struct usb_serial *serial = usb_get_intfdata(intf);

	int rv;



	usb_serial_unpoison_port_urbs(serial);



	serial->suspending = 0;

	if (serial->type->reset_resume)

		rv = serial->type->reset_resume(serial);