- DECLARE_WAITQUEUE(wait, current);
- int retval, do_clocal = 0;
- unsigned long flags;
-
- if (tty_hung_up_p(filp)) {
- if (ch->port.flags & ASYNC_HUP_NOTIFY)
- retval = -EAGAIN;
- else
- retval = -ERESTARTSYS;
- return retval;
- }
-
- /*
- * If the device is in the middle of being closed, then block until
- * it's done, and then try again.
- */
- if (ch->port.flags & ASYNC_CLOSING) {
- interruptible_sleep_on(&ch->port.close_wait);
-
- if (ch->port.flags & ASYNC_HUP_NOTIFY)
- return -EAGAIN;
- else
- return -ERESTARTSYS;
- }
-
- if (filp->f_flags & O_NONBLOCK) {
- /*
- * If non-blocking mode is set, then make the check up front
- * and then exit.
- */
- ch->port.flags |= ASYNC_NORMAL_ACTIVE;
- return 0;
- }
- if (tty->termios->c_cflag & CLOCAL)
- do_clocal = 1;
- /* Block waiting for the carrier detect and the line to become free */
-
- retval = 0;
- add_wait_queue(&ch->port.open_wait, &wait);
-
- spin_lock_irqsave(&epca_lock, flags);
- /* We dec count so that pc_close will know when to free things */
- if (!tty_hung_up_p(filp))
- ch->port.count--;
- ch->port.blocked_open++;
- while (1) {
- set_current_state(TASK_INTERRUPTIBLE);
- if (tty_hung_up_p(filp) ||
- !(ch->port.flags & ASYNC_INITIALIZED)) {
- if (ch->port.flags & ASYNC_HUP_NOTIFY)
- retval = -EAGAIN;
- else
- retval = -ERESTARTSYS;
- break;
- }
- if (!(ch->port.flags & ASYNC_CLOSING) &&
- (do_clocal || (ch->imodem & ch->dcd)))
- break;
- if (signal_pending(current)) {
- retval = -ERESTARTSYS;
- break;
- }
- spin_unlock_irqrestore(&epca_lock, flags);
- /*
- * Allow someone else to be scheduled. We will occasionally go
- * through this loop until one of the above conditions change.
- * The below schedule call will allow other processes to enter
- * and prevent this loop from hogging the cpu.
- */
- schedule();
- spin_lock_irqsave(&epca_lock, flags);
- }
-
- __set_current_state(TASK_RUNNING);
- remove_wait_queue(&ch->port.open_wait, &wait);
- if (!tty_hung_up_p(filp))
- ch->port.count++;
- ch->port.blocked_open--;
-
- spin_unlock_irqrestore(&epca_lock, flags);
-
- if (retval)
- return retval;
-
- ch->port.flags |= ASYNC_NORMAL_ACTIVE;