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path: root/drivers/usb/serial/usb-serial.c
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Diffstat (limited to 'drivers/usb/serial/usb-serial.c')
-rw-r--r--drivers/usb/serial/usb-serial.c144
1 files changed, 100 insertions, 44 deletions
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index f331e2bde88..1967a7edc10 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -238,9 +238,11 @@ static int serial_open (struct tty_struct *tty, struct file *filp)
goto bailout_interface_put;
mutex_unlock(&serial->disc_mutex);
}
-
mutex_unlock(&port->mutex);
- return 0;
+ /* Now do the correct tty layer semantics */
+ retval = tty_port_block_til_ready(&port->port, tty, filp);
+ if (retval == 0)
+ return 0;
bailout_interface_put:
usb_autopm_put_interface(serial->interface);
@@ -259,64 +261,89 @@ bailout_serial_put:
return retval;
}
-static void serial_close(struct tty_struct *tty, struct file *filp)
+/**
+ * serial_do_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
+ */
+static void serial_do_down(struct usb_serial_port *port)
{
- struct usb_serial_port *port = tty->driver_data;
+ struct usb_serial_driver *drv = port->serial->type;
struct usb_serial *serial;
struct module *owner;
- int count;
- if (!port)
+ /* 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);
-
mutex_lock(&port->mutex);
serial = port->serial;
owner = serial->type->driver.owner;
- if (port->port.count == 0) {
- mutex_unlock(&port->mutex);
- return;
- }
-
- if (port->port.count == 1)
- /* only call the device specific close if this
- * port is being closed by the last owner. Ensure we do
- * this before we drop the port count. The call is protected
- * by the port mutex
- */
- serial->type->close(tty, port, filp);
-
- if (port->port.count == (port->console ? 2 : 1)) {
- struct tty_struct *tty = tty_port_tty_get(&port->port);
- if (tty) {
- /* We must do this before we drop the port count to
- zero. */
- if (tty->driver_data)
- tty->driver_data = NULL;
- tty_port_tty_set(&port->port, NULL);
- tty_kref_put(tty);
- }
- }
+ if (drv->close)
+ drv->close(port);
- --port->port.count;
- count = port->port.count;
mutex_unlock(&port->mutex);
- put_device(&port->dev);
+}
+
+/**
+ * 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)
+{
+ 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;
+
+ serial = port->serial;
+ owner = serial->type->driver.owner;
+ 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);
- }
+ 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);
+ module_put(owner);
+}
+
+static void serial_close(struct tty_struct *tty, struct file *filp)
+{
+ struct usb_serial_port *port = tty->driver_data;
+
+ dbg("%s - port %d", __func__, port->number);
+
+
+ if (tty_port_close_start(&port->port, tty, filp) == 0)
+ return;
+
+ serial_do_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)
+{
+ struct usb_serial_port *port = tty->driver_data;
+ serial_do_down(port);
+ tty_port_hangup(&port->port);
+ serial_do_free(port);
}
static int serial_write(struct tty_struct *tty, const unsigned char *buf,
@@ -648,6 +675,29 @@ static struct usb_serial_driver *search_serial_device(
return NULL;
}
+static int serial_carrier_raised(struct tty_port *port)
+{
+ struct usb_serial_port *p = container_of(port, struct usb_serial_port, port);
+ struct usb_serial_driver *drv = p->serial->type;
+ if (drv->carrier_raised)
+ return drv->carrier_raised(p);
+ /* No carrier control - don't block */
+ return 1;
+}
+
+static void serial_dtr_rts(struct tty_port *port, int on)
+{
+ struct usb_serial_port *p = container_of(port, struct usb_serial_port, port);
+ struct usb_serial_driver *drv = p->serial->type;
+ if (drv->dtr_rts)
+ drv->dtr_rts(p, on);
+}
+
+static const struct tty_port_operations serial_port_ops = {
+ .carrier_raised = serial_carrier_raised,
+ .dtr_rts = serial_dtr_rts,
+};
+
int usb_serial_probe(struct usb_interface *interface,
const struct usb_device_id *id)
{
@@ -841,6 +891,7 @@ int usb_serial_probe(struct usb_interface *interface,
if (!port)
goto probe_error;
tty_port_init(&port->port);
+ port->port.ops = &serial_port_ops;
port->serial = serial;
spin_lock_init(&port->lock);
mutex_init(&port->mutex);
@@ -1071,6 +1122,9 @@ 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_kref_put(tty);
}
@@ -1135,6 +1189,7 @@ static const struct tty_operations serial_ops = {
.open = serial_open,
.close = serial_close,
.write = serial_write,
+ .hangup = serial_hangup,
.write_room = serial_write_room,
.ioctl = serial_ioctl,
.set_termios = serial_set_termios,
@@ -1147,6 +1202,7 @@ static const struct tty_operations serial_ops = {
.proc_fops = &serial_proc_fops,
};
+
struct tty_driver *usb_serial_tty_driver;
static int __init usb_serial_init(void)