diff options
Diffstat (limited to 'drivers/usb/serial/usb-serial.c')
| -rw-r--r-- | drivers/usb/serial/usb-serial.c | 129 |
1 files changed, 23 insertions, 106 deletions
diff --git a/drivers/usb/serial/usb-serial.c b/drivers/usb/serial/usb-serial.c index a9934a3f984..0cb0d77dc42 100644 --- a/drivers/usb/serial/usb-serial.c +++ b/drivers/usb/serial/usb-serial.c @@ -296,16 +296,14 @@ static int serial_write (struct tty_struct * tty, const unsigned char *buf, int struct usb_serial_port *port = tty->driver_data; int retval = -ENODEV; - if (!port || port->serial->dev->state == USB_STATE_NOTATTACHED) + if (port->serial->dev->state == USB_STATE_NOTATTACHED) goto exit; dbg("%s - port %d, %d byte(s)", __func__, port->number, count); - if (!port->open_count) { - retval = -EINVAL; - dbg("%s - port not opened", __func__); - goto exit; - } + /* open_count is managed under the mutex lock for the tty so cannot + drop to zero until after the last close completes */ + WARN_ON(!port->open_count); /* pass on to the driver specific version of this function */ retval = port->serial->type->write(port, buf, count); @@ -317,61 +315,28 @@ exit: static int serial_write_room (struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; - int retval = -ENODEV; - - if (!port) - goto exit; - dbg("%s - port %d", __func__, port->number); - - if (!port->open_count) { - dbg("%s - port not open", __func__); - goto exit; - } - + WARN_ON(!port->open_count); /* pass on to the driver specific version of this function */ - retval = port->serial->type->write_room(port); - -exit: - return retval; + return port->serial->type->write_room(port); } static int serial_chars_in_buffer (struct tty_struct *tty) { struct usb_serial_port *port = tty->driver_data; - int retval = -ENODEV; - - if (!port) - goto exit; - dbg("%s = port %d", __func__, port->number); - if (!port->open_count) { - dbg("%s - port not open", __func__); - goto exit; - } - + WARN_ON(!port->open_count); /* pass on to the driver specific version of this function */ - retval = port->serial->type->chars_in_buffer(port); - -exit: - return retval; + return port->serial->type->chars_in_buffer(port); } static void serial_throttle (struct tty_struct * tty) { struct usb_serial_port *port = tty->driver_data; - - if (!port) - return; - dbg("%s - port %d", __func__, port->number); - if (!port->open_count) { - dbg ("%s - port not open", __func__); - return; - } - + WARN_ON(!port->open_count); /* pass on to the driver specific version of this function */ if (port->serial->type->throttle) port->serial->type->throttle(port); @@ -380,17 +345,9 @@ static void serial_throttle (struct tty_struct * tty) static void serial_unthrottle (struct tty_struct * tty) { struct usb_serial_port *port = tty->driver_data; - - if (!port) - return; - dbg("%s - port %d", __func__, port->number); - if (!port->open_count) { - dbg("%s - port not open", __func__); - return; - } - + WARN_ON(!port->open_count); /* pass on to the driver specific version of this function */ if (port->serial->type->unthrottle) port->serial->type->unthrottle(port); @@ -401,42 +358,27 @@ static int serial_ioctl (struct tty_struct *tty, struct file * file, unsigned in struct usb_serial_port *port = tty->driver_data; int retval = -ENODEV; - lock_kernel(); - if (!port) - goto exit; - dbg("%s - port %d, cmd 0x%.4x", __func__, port->number, cmd); - /* Caution - port->open_count is BKL protected */ - if (!port->open_count) { - dbg ("%s - port not open", __func__); - goto exit; - } + WARN_ON(!port->open_count); /* pass on to the driver specific version of this function if it is available */ - if (port->serial->type->ioctl) + if (port->serial->type->ioctl) { + lock_kernel(); retval = port->serial->type->ioctl(port, file, cmd, arg); + unlock_kernel(); + } else retval = -ENOIOCTLCMD; -exit: - unlock_kernel(); return retval; } static void serial_set_termios (struct tty_struct *tty, struct ktermios * old) { struct usb_serial_port *port = tty->driver_data; - - if (!port) - return; - dbg("%s - port %d", __func__, port->number); - if (!port->open_count) { - dbg("%s - port not open", __func__); - return; - } - + WARN_ON(!port->open_count); /* pass on to the driver specific version of this function if it is available */ if (port->serial->type->set_termios) port->serial->type->set_termios(port, old); @@ -448,24 +390,15 @@ static void serial_break (struct tty_struct *tty, int break_state) { struct usb_serial_port *port = tty->driver_data; - lock_kernel(); - if (!port) { - unlock_kernel(); - return; - } - dbg("%s - port %d", __func__, port->number); - if (!port->open_count) { - dbg("%s - port not open", __func__); - unlock_kernel(); - return; - } - + WARN_ON(!port->open_count); /* pass on to the driver specific version of this function if it is available */ - if (port->serial->type->break_ctl) + if (port->serial->type->break_ctl) { + lock_kernel(); port->serial->type->break_ctl(port, break_state); - unlock_kernel(); + unlock_kernel(); + } } static int serial_read_proc (char *page, char **start, off_t off, int count, int *eof, void *data) @@ -519,19 +452,11 @@ static int serial_tiocmget (struct tty_struct *tty, struct file *file) { struct usb_serial_port *port = tty->driver_data; - if (!port) - return -ENODEV; - dbg("%s - port %d", __func__, port->number); - if (!port->open_count) { - dbg("%s - port not open", __func__); - return -ENODEV; - } - + WARN_ON(!port->open_count); if (port->serial->type->tiocmget) return port->serial->type->tiocmget(port, file); - return -EINVAL; } @@ -540,19 +465,11 @@ static int serial_tiocmset (struct tty_struct *tty, struct file *file, { struct usb_serial_port *port = tty->driver_data; - if (!port) - return -ENODEV; - dbg("%s - port %d", __func__, port->number); - if (!port->open_count) { - dbg("%s - port not open", __func__); - return -ENODEV; - } - + WARN_ON(!port->open_count); if (port->serial->type->tiocmset) return port->serial->type->tiocmset(port, file, set, clear); - return -EINVAL; } |