diff options
Diffstat (limited to 'drivers/char/n_tty.c')
-rw-r--r-- | drivers/char/n_tty.c | 66 |
1 files changed, 37 insertions, 29 deletions
diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c index c556f4d3ccd7..ccad7ae94541 100644 --- a/drivers/char/n_tty.c +++ b/drivers/char/n_tty.c @@ -78,7 +78,32 @@ static inline void free_buf(unsigned char *buf) free_page((unsigned long) buf); } -static inline void put_tty_queue_nolock(unsigned char c, struct tty_struct *tty) +/** + * n_tty_set__room - receive space + * @tty: terminal + * + * Called by the driver to find out how much data it is + * permitted to feed to the line discipline without any being lost + * and thus to manage flow control. Not serialized. Answers for the + * "instant". + */ + +static void n_tty_set_room(struct tty_struct *tty) +{ + int left = N_TTY_BUF_SIZE - tty->read_cnt - 1; + + /* + * If we are doing input canonicalization, and there are no + * pending newlines, let characters through without limit, so + * that erase characters will be handled. Other excess + * characters will be beeped. + */ + if (left <= 0) + left = tty->icanon && !tty->canon_data; + tty->receive_room = left; +} + +static void put_tty_queue_nolock(unsigned char c, struct tty_struct *tty) { if (tty->read_cnt < N_TTY_BUF_SIZE) { tty->read_buf[tty->read_head] = c; @@ -87,7 +112,7 @@ static inline void put_tty_queue_nolock(unsigned char c, struct tty_struct *tty) } } -static inline void put_tty_queue(unsigned char c, struct tty_struct *tty) +static void put_tty_queue(unsigned char c, struct tty_struct *tty) { unsigned long flags; /* @@ -136,6 +161,7 @@ static void reset_buffer_flags(struct tty_struct *tty) spin_unlock_irqrestore(&tty->read_lock, flags); tty->canon_head = tty->canon_data = tty->erasing = 0; memset(&tty->read_flags, 0, sizeof tty->read_flags); + n_tty_set_room(tty); check_unthrottle(tty); } @@ -838,30 +864,6 @@ send_signal: put_tty_queue(c, tty); } -/** - * n_tty_receive_room - receive space - * @tty: terminal - * - * Called by the driver to find out how much data it is - * permitted to feed to the line discipline without any being lost - * and thus to manage flow control. Not serialized. Answers for the - * "instant". - */ - -static int n_tty_receive_room(struct tty_struct *tty) -{ - int left = N_TTY_BUF_SIZE - tty->read_cnt - 1; - - /* - * If we are doing input canonicalization, and there are no - * pending newlines, let characters through without limit, so - * that erase characters will be handled. Other excess - * characters will be beeped. - */ - if (left <= 0) - left = tty->icanon && !tty->canon_data; - return left; -} /** * n_tty_write_wakeup - asynchronous I/O notifier @@ -953,6 +955,8 @@ static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp, tty->driver->flush_chars(tty); } + n_tty_set_room(tty); + if (!tty->icanon && (tty->read_cnt >= tty->minimum_to_wake)) { kill_fasync(&tty->fasync, SIGIO, POLL_IN); if (waitqueue_active(&tty->read_wait)) @@ -964,7 +968,7 @@ static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp, * mode. We don't want to throttle the driver if we're in * canonical mode and don't have a newline yet! */ - if (n_tty_receive_room(tty) < TTY_THRESHOLD_THROTTLE) { + if (tty->receive_room < TTY_THRESHOLD_THROTTLE) { /* check TTY_THROTTLED first so it indicates our state */ if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) && tty->driver->throttle) @@ -999,6 +1003,7 @@ static void n_tty_set_termios(struct tty_struct *tty, struct termios * old) if (test_bit(TTY_HW_COOK_IN, &tty->flags)) { tty->raw = 1; tty->real_raw = 1; + n_tty_set_room(tty); return; } if (I_ISTRIP(tty) || I_IUCLC(tty) || I_IGNCR(tty) || @@ -1051,6 +1056,7 @@ static void n_tty_set_termios(struct tty_struct *tty, struct termios * old) else tty->real_raw = 0; } + n_tty_set_room(tty); } /** @@ -1130,7 +1136,7 @@ static inline int input_available_p(struct tty_struct *tty, int amt) * */ -static inline int copy_from_read_buf(struct tty_struct *tty, +static int copy_from_read_buf(struct tty_struct *tty, unsigned char __user **b, size_t *nr) @@ -1308,6 +1314,7 @@ do_it_again: retval = -ERESTARTSYS; break; } + n_tty_set_room(tty); clear_bit(TTY_DONT_FLIP, &tty->flags); timeout = schedule_timeout(timeout); set_bit(TTY_DONT_FLIP, &tty->flags); @@ -1401,6 +1408,8 @@ do_it_again: } else if (test_and_clear_bit(TTY_PUSH, &tty->flags)) goto do_it_again; + n_tty_set_room(tty); + return retval; } @@ -1553,7 +1562,6 @@ struct tty_ldisc tty_ldisc_N_TTY = { normal_poll, /* poll */ NULL, /* hangup */ n_tty_receive_buf, /* receive_buf */ - n_tty_receive_room, /* receive_room */ n_tty_write_wakeup /* write_wakeup */ }; |