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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.c26
1 files changed, 15 insertions, 11 deletions
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c
index 794b5ffe439..080ade223d5 100644
--- a/drivers/usb/serial/usb-serial.c
+++ b/drivers/usb/serial/usb-serial.c
@@ -269,15 +269,19 @@ static void serial_close(struct tty_struct *tty, struct file *filp)
return;
}
- --port->port.count;
- if (port->port.count == 0)
+ if (port->port.count == 1)
/* only call the device specific close if this
- * port is being closed by the last owner */
+ * 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
+ */
port->serial->type->close(tty, port, filp);
- if (port->port.count == (port->console? 1 : 0)) {
+ 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);
@@ -285,13 +289,14 @@ static void serial_close(struct tty_struct *tty, struct file *filp)
}
}
- if (port->port.count == 0) {
+ if (port->port.count == 1) {
mutex_lock(&port->serial->disc_mutex);
if (!port->serial->disconnected)
usb_autopm_put_interface(port->serial->interface);
mutex_unlock(&port->serial->disc_mutex);
module_put(port->serial->type->driver.owner);
}
+ --port->port.count;
mutex_unlock(&port->mutex);
usb_serial_put(port->serial);
@@ -334,6 +339,10 @@ static int serial_chars_in_buffer(struct tty_struct *tty)
dbg("%s = port %d", __func__, port->number);
WARN_ON(!port->port.count);
+ /* if the device was unplugged then any remaining characters
+ fell out of the connector ;) */
+ if (port->serial->disconnected)
+ return 0;
/* pass on to the driver specific version of this function */
return port->serial->type->chars_in_buffer(tty);
}
@@ -373,9 +382,7 @@ static int serial_ioctl(struct tty_struct *tty, struct file *file,
/* pass on to the driver specific version of this function
if it is available */
if (port->serial->type->ioctl) {
- lock_kernel();
retval = port->serial->type->ioctl(tty, file, cmd, arg);
- unlock_kernel();
} else
retval = -ENOIOCTLCMD;
return retval;
@@ -404,11 +411,8 @@ static int serial_break(struct tty_struct *tty, int break_state)
WARN_ON(!port->port.count);
/* pass on to the driver specific version of this function
if it is available */
- if (port->serial->type->break_ctl) {
- lock_kernel();
+ if (port->serial->type->break_ctl)
port->serial->type->break_ctl(tty, break_state);
- unlock_kernel();
- }
return 0;
}