tty: usb-serial krefs
Use kref in the USB serial drivers so that we don't free tty structures
from under the URB receive handlers as has historically been the case if
you were unlucky. This also gives us a framework for general tty drivers to
use tty_port objects and refcount.
Contains two err->dev_err changes merged together to fix clashes in the
-next tree.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 4f7f9e3..e7d4246 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -214,7 +214,7 @@
/* set up our port structure making the tty driver
* remember our port object, and us it */
tty->driver_data = port;
- port->port.tty = tty;
+ tty_port_tty_set(&port->port, tty);
if (port->port.count == 1) {
@@ -246,7 +246,7 @@
bailout_mutex_unlock:
port->port.count = 0;
tty->driver_data = NULL;
- port->port.tty = NULL;
+ tty_port_tty_set(&port->port, NULL);
mutex_unlock(&port->mutex);
bailout_kref_put:
usb_serial_put(serial);
@@ -276,10 +276,11 @@
port->serial->type->close(tty, port, filp);
if (port->port.count == (port->console? 1 : 0)) {
- if (port->port.tty) {
- if (port->port.tty->driver_data)
- port->port.tty->driver_data = NULL;
- port->port.tty = NULL;
+ struct tty_struct *tty = tty_port_tty_get(&port->port);
+ if (tty) {
+ if (tty->driver_data)
+ tty->driver_data = NULL;
+ tty_port_tty_set(&port->port, NULL);
}
}
@@ -508,11 +509,12 @@
if (!port)
return;
- tty = port->port.tty;
+ tty = tty_port_tty_get(&port->port);
if (!tty)
return;
tty_wakeup(tty);
+ tty_kref_put(tty);
}
static void port_release(struct device *dev)
@@ -819,6 +821,7 @@
port = kzalloc(sizeof(struct usb_serial_port), GFP_KERNEL);
if (!port)
goto probe_error;
+ tty_port_init(&port->port);
port->serial = serial;
spin_lock_init(&port->lock);
mutex_init(&port->mutex);
@@ -1040,8 +1043,11 @@
for (i = 0; i < serial->num_ports; ++i) {
port = serial->port[i];
if (port) {
- if (port->port.tty)
- tty_hangup(port->port.tty);
+ struct tty_struct *tty = tty_port_tty_get(&port->port);
+ if (tty) {
+ tty_hangup(tty);
+ tty_kref_put(tty);
+ }
kill_traffic(port);
}
}