/*
* rs_hangup() --- called by tty_hangup() when a hangup is signaled.
*/
static void rs_hangup(struct tty_struct *tty)
{
struct serial_state *info = tty->driver_data;
if (serial_paranoia_check(info, tty->name, "rs_hangup"))
return;
rs_flush_buffer(tty);
shutdown(tty, info);
info->tport.count = 0;
tty_port_set_active(&info->tport, 0);
info->tport.tty = NULL;
wake_up_interruptible(&info->tport.open_wait);
}
void tty_port_hangup(struct tty_port *port)
{
struct tty_struct *tty;
unsigned long flags;
spin_lock_irqsave(&port->lock, flags);
port->count = 0;
tty = port->tty;
if (tty)
set_bit(TTY_IO_ERROR, &tty->flags);
port->tty = NULL;
spin_unlock_irqrestore(&port->lock, flags);
tty_port_set_active(port, 0);
tty_port_shutdown(port, tty);
tty_kref_put(tty);
wake_up_interruptible(&port->open_wait);
wake_up_interruptible(&port->delta_msr_wait);
}
int tty_port_block_til_ready(struct tty_port *port,
struct tty_struct *tty, struct file *filp)
{
int do_clocal = 0, retval;
unsigned long flags;
DEFINE_WAIT(wait);
/* if non-blocking mode is set we can pass directly to open unless
the port has just hung up or is in another error state */
if (tty_io_error(tty)) {
tty_port_set_active(port, 1);
return 0;
}
if (filp == NULL || (filp->f_flags & O_NONBLOCK)) {
/* Indicate we are open */
if (C_BAUD(tty))
tty_port_raise_dtr_rts(port);
tty_port_set_active(port, 1);
return 0;
}
if (C_CLOCAL(tty))
do_clocal = 1;
/* Block waiting until we can proceed. We may need to wait for the
carrier, but we must also wait for any close that is in progress
before the next open may complete */
retval = 0;
/* The port lock protects the port counts */
spin_lock_irqsave(&port->lock, flags);
port->count--;
port->blocked_open++;
spin_unlock_irqrestore(&port->lock, flags);
while (1) {
/* Indicate we are open */
if (C_BAUD(tty) && tty_port_initialized(port))
tty_port_raise_dtr_rts(port);
prepare_to_wait(&port->open_wait, &wait, TASK_INTERRUPTIBLE);
/* Check for a hangup or uninitialised port.
Return accordingly */
if (tty_hung_up_p(filp) || !tty_port_initialized(port)) {
if (port->flags & ASYNC_HUP_NOTIFY)
retval = -EAGAIN;
else
retval = -ERESTARTSYS;
break;
}
/*
* Probe the carrier. For devices with no carrier detect
* tty_port_carrier_raised will always return true.
* Never ask drivers if CLOCAL is set, this causes troubles
* on some hardware.
*/
if (do_clocal || tty_port_carrier_raised(port))
break;
if (signal_pending(current)) {
retval = -ERESTARTSYS;
break;
}
tty_unlock(tty);
schedule();
tty_lock(tty);
}
finish_wait(&port->open_wait, &wait);
/* Update counts. A parallel hangup will have set count to zero and
we must not mess that up further */
spin_lock_irqsave(&port->lock, flags);
if (!tty_hung_up_p(filp))
port->count++;
port->blocked_open--;
spin_unlock_irqrestore(&port->lock, flags);
if (retval == 0)
tty_port_set_active(port, 1);
return retval;
}
