diff options
| -rw-r--r-- | drivers/tty/n_tty.c | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 4ddfa60c9222..b60b043f47d8 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -187,10 +187,10 @@ static int receive_room(struct tty_struct *tty) } /** - * n_tty_set_room - receive space + * n_tty_kick_worker - start input worker (if required) * @tty: terminal * - * Re-schedules the flip buffer work if space just became available. + * Re-schedules the flip buffer work if it may have stopped * * Caller holds exclusive termios_rwsem * or @@ -198,12 +198,12 @@ static int receive_room(struct tty_struct *tty) * holds non-exclusive termios_rwsem */ -static void n_tty_set_room(struct tty_struct *tty) +static void n_tty_kick_worker(struct tty_struct *tty) { struct n_tty_data *ldata = tty->disc_data; - /* Did this open up the receive buffer? We may need to flip */ - if (unlikely(ldata->no_room) && receive_room(tty)) { + /* Did the input worker stop? Restart it */ + if (unlikely(ldata->no_room)) { ldata->no_room = 0; WARN_RATELIMIT(tty->port->itty == NULL, @@ -274,7 +274,7 @@ static void n_tty_check_unthrottle(struct tty_struct *tty) return; if (!tty->count) return; - n_tty_set_room(tty); + n_tty_kick_worker(tty); n_tty_write_wakeup(tty->link); if (waitqueue_active(&tty->link->write_wait)) wake_up_interruptible_poll(&tty->link->write_wait, POLLOUT); @@ -296,7 +296,7 @@ static void n_tty_check_unthrottle(struct tty_struct *tty) break; if (!tty->count) break; - n_tty_set_room(tty); + n_tty_kick_worker(tty); unthrottled = tty_unthrottle_safe(tty); if (!unthrottled) break; @@ -379,7 +379,7 @@ static void n_tty_flush_buffer(struct tty_struct *tty) { down_write(&tty->termios_rwsem); reset_buffer_flags(tty->disc_data); - n_tty_set_room(tty); + n_tty_kick_worker(tty); if (tty->link) n_tty_packet_mode_flush(tty); @@ -1817,7 +1817,6 @@ static void n_tty_set_termios(struct tty_struct *tty, struct ktermios *old) else ldata->real_raw = 0; } - n_tty_set_room(tty); /* * Fix tty hang when I_IXON(tty) is cleared, but the tty * been stopped by STOP_CHAR(tty) before it. @@ -2130,6 +2129,7 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, ssize_t retval = 0; long timeout; int packet; + size_t tail; c = job_control(tty, file); if (c < 0) @@ -2166,6 +2166,7 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, } packet = tty->packet; + tail = ldata->read_tail; add_wait_queue(&tty->read_wait, &wait); while (nr) { @@ -2208,7 +2209,6 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, retval = -ERESTARTSYS; break; } - n_tty_set_room(tty); up_read(&tty->termios_rwsem); timeout = wait_woken(&wait, TASK_INTERRUPTIBLE, @@ -2253,7 +2253,8 @@ static ssize_t n_tty_read(struct tty_struct *tty, struct file *file, if (time) timeout = time; } - n_tty_set_room(tty); + if (tail != ldata->read_tail) + n_tty_kick_worker(tty); up_read(&tty->termios_rwsem); remove_wait_queue(&tty->read_wait, &wait); |