void tty_ldisc_hangup(struct tty_struct *tty)
{
struct tty_ldisc *ld;
int reset = tty->driver->flags & TTY_DRIVER_RESET_TERMIOS;
int err = 0;
/*
* FIXME! What are the locking issues here? This may me overdoing
* things... This question is especially important now that we've
* removed the irqlock.
*/
ld = tty_ldisc_ref(tty);
if (ld != NULL) {
/* We may have no line discipline at this point */
if (ld->ops->flush_buffer)
ld->ops->flush_buffer(tty);
tty_driver_flush_buffer(tty);
if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&
ld->ops->write_wakeup)
ld->ops->write_wakeup(tty);
if (ld->ops->hangup)
ld->ops->hangup(tty);
tty_ldisc_deref(ld);
}
/*
* FIXME: Once we trust the LDISC code better we can wait here for
* ldisc completion and fix the driver call race
*/
wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
wake_up_interruptible_poll(&tty->read_wait, POLLIN);
/*
* Shutdown the current line discipline, and reset it to
* N_TTY if need be.
*
* Avoid racing set_ldisc or tty_ldisc_release
*/
mutex_lock(&tty->ldisc_mutex);
tty_ldisc_halt(tty);
/* At this point we have a closed ldisc and we want to
reopen it. We could defer this to the next open but
it means auditing a lot of other paths so this is
a FIXME */
if (tty->ldisc) { /* Not yet closed */
if (reset == 0) {
tty_ldisc_reinit(tty, tty->termios->c_line);
err = tty_ldisc_open(tty, tty->ldisc);
}
/* If the re-open fails or we reset then go to N_TTY. The
N_TTY open cannot fail */
if (reset || err) {
tty_ldisc_reinit(tty, N_TTY);
WARN_ON(tty_ldisc_open(tty, tty->ldisc));
}
tty_ldisc_enable(tty);
}
mutex_unlock(&tty->ldisc_mutex);
if (reset)
tty_reset_termios(tty);
}
void tty_ldisc_hangup(struct tty_struct *tty)
{
struct tty_ldisc *ld;
int reset = tty->driver->flags & TTY_DRIVER_RESET_TERMIOS;
int err = 0;
tty_ldisc_debug(tty, "closing ldisc: %p\n", tty->ldisc);
ld = tty_ldisc_ref(tty);
if (ld != NULL) {
if (ld->ops->flush_buffer)
ld->ops->flush_buffer(tty);
tty_driver_flush_buffer(tty);
if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&
ld->ops->write_wakeup)
ld->ops->write_wakeup(tty);
if (ld->ops->hangup)
ld->ops->hangup(tty);
tty_ldisc_deref(ld);
}
wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
wake_up_interruptible_poll(&tty->read_wait, POLLIN);
tty_unlock(tty);
/*
* Shutdown the current line discipline, and reset it to
* N_TTY if need be.
*
* Avoid racing set_ldisc or tty_ldisc_release
*/
tty_ldisc_lock_pair(tty, tty->link);
tty_lock(tty);
if (tty->ldisc) {
/* At this point we have a halted ldisc; we want to close it and
reopen a new ldisc. We could defer the reopen to the next
open but it means auditing a lot of other paths so this is
a FIXME */
if (reset == 0) {
if (!tty_ldisc_reinit(tty, tty->termios.c_line))
err = tty_ldisc_open(tty, tty->ldisc);
else
err = 1;
}
/* If the re-open fails or we reset then go to N_TTY. The
N_TTY open cannot fail */
if (reset || err) {
BUG_ON(tty_ldisc_reinit(tty, N_TTY));
WARN_ON(tty_ldisc_open(tty, tty->ldisc));
}
}
tty_ldisc_enable_pair(tty, tty->link);
if (reset)
tty_reset_termios(tty);
tty_ldisc_debug(tty, "re-opened ldisc: %p\n", tty->ldisc);
}
void tty_ldisc_hangup(struct tty_struct *tty)
{
struct tty_ldisc *ld;
int reset = tty->driver->flags & TTY_DRIVER_RESET_TERMIOS;
int err = 0;
/*
* FIXME! What are the locking issues here? This may me overdoing
* things... This question is especially important now that we've
* removed the irqlock.
*/
ld = tty_ldisc_ref(tty);
if (ld != NULL) {
/* We may have no line discipline at this point */
if (ld->ops->flush_buffer)
ld->ops->flush_buffer(tty);
tty_driver_flush_buffer(tty);
if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&
ld->ops->write_wakeup)
ld->ops->write_wakeup(tty);
if (ld->ops->hangup)
ld->ops->hangup(tty);
tty_ldisc_deref(ld);
}
/*
* FIXME: Once we trust the LDISC code better we can wait here for
* ldisc completion and fix the driver call race
*/
wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
wake_up_interruptible_poll(&tty->read_wait, POLLIN);
/*
* Shutdown the current line discipline, and reset it to
* N_TTY if need be.
*
* Avoid racing set_ldisc or tty_ldisc_release
*/
mutex_lock(&tty->ldisc_mutex);
/*
* this is like tty_ldisc_halt, but we need to give up
* the BTM before calling cancel_work_sync, which may
* need to wait for another function taking the BTM
*/
clear_bit(TTY_LDISC, &tty->flags);
tty_unlock(tty);
cancel_work_sync(&tty->port->buf.work);
mutex_unlock(&tty->ldisc_mutex);
retry:
tty_lock(tty);
mutex_lock(&tty->ldisc_mutex);
/* At this point we have a closed ldisc and we want to
reopen it. We could defer this to the next open but
it means auditing a lot of other paths so this is
a FIXME */
if (tty->ldisc) { /* Not yet closed */
if (atomic_read(&tty->ldisc->users) != 1) {
char cur_n[TASK_COMM_LEN], tty_n[64];
long timeout = 3 * HZ;
tty_unlock(tty);
while (tty_ldisc_wait_idle(tty, timeout) == -EBUSY) {
timeout = MAX_SCHEDULE_TIMEOUT;
printk_ratelimited(KERN_WARNING
"%s: waiting (%s) for %s took too long, but we keep waiting...\n",
__func__, get_task_comm(cur_n, current),
tty_name(tty, tty_n));
}
mutex_unlock(&tty->ldisc_mutex);
goto retry;
}
if (reset == 0) {
if (!tty_ldisc_reinit(tty, tty->termios.c_line))
err = tty_ldisc_open(tty, tty->ldisc);
else
err = 1;
}
/* If the re-open fails or we reset then go to N_TTY. The
N_TTY open cannot fail */
if (reset || err) {
BUG_ON(tty_ldisc_reinit(tty, N_TTY));
WARN_ON(tty_ldisc_open(tty, tty->ldisc));
}
tty_ldisc_enable(tty);
}
mutex_unlock(&tty->ldisc_mutex);
if (reset)
tty_reset_termios(tty);
}
void tty_ldisc_hangup(struct tty_struct *tty)
{
struct tty_ldisc *ld;
int reset = tty->driver->flags & TTY_DRIVER_RESET_TERMIOS;
int err = 0;
ld = tty_ldisc_ref(tty);
if (ld != NULL) {
/* We may have no line discipline at this point */
if (ld->ops->flush_buffer)
ld->ops->flush_buffer(tty);
tty_driver_flush_buffer(tty);
if ((test_bit(TTY_DO_WRITE_WAKEUP, &tty->flags)) &&
ld->ops->write_wakeup)
ld->ops->write_wakeup(tty);
if (ld->ops->hangup)
ld->ops->hangup(tty);
tty_ldisc_deref(ld);
}
wake_up_interruptible_poll(&tty->write_wait, POLLOUT);
wake_up_interruptible_poll(&tty->read_wait, POLLIN);
/*
* Shutdown the current line discipline, and reset it to
* N_TTY if need be.
*
* Avoid racing set_ldisc or tty_ldisc_release
*/
mutex_lock(&tty->ldisc_mutex);
/*
* this is like tty_ldisc_halt, but we need to give up
* the BTM before calling cancel_delayed_work_sync,
* which may need to wait for another function taking the BTM
*/
clear_bit(TTY_LDISC, &tty->flags);
tty_unlock();
cancel_delayed_work_sync(&tty->buf.work);
mutex_unlock(&tty->ldisc_mutex);
tty_lock();
mutex_lock(&tty->ldisc_mutex);
if (tty->ldisc) { /* Not yet closed */
if (reset == 0) {
if (!tty_ldisc_reinit(tty, tty->termios->c_line))
err = tty_ldisc_open(tty, tty->ldisc);
else
err = 1;
}
/* If the re-open fails or we reset then go to N_TTY. The
N_TTY open cannot fail */
if (reset || err) {
BUG_ON(tty_ldisc_reinit(tty, N_TTY));
WARN_ON(tty_ldisc_open(tty, tty->ldisc));
}
tty_ldisc_enable(tty);
}
mutex_unlock(&tty->ldisc_mutex);
if (reset)
tty_reset_termios(tty);
}
