diff options
Diffstat (limited to 'drivers/tty/pty.c')
| -rw-r--r-- | drivers/tty/pty.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/tty/pty.c b/drivers/tty/pty.c index 9bbdb1de12e2..7c4447a5c0f4 100644 --- a/drivers/tty/pty.c +++ b/drivers/tty/pty.c @@ -24,6 +24,7 @@ #include <linux/devpts_fs.h> #include <linux/slab.h> #include <linux/mutex.h> +#include <linux/poll.h> #ifdef CONFIG_UNIX98_PTYS @@ -313,6 +314,42 @@ done: } /** + * pty_start - start() handler + * pty_stop - stop() handler + * @tty: tty being flow-controlled + * + * Propagates the TIOCPKT status to the master pty. + * + * NB: only the master pty can be in packet mode so only the slave + * needs start()/stop() handlers + */ +static void pty_start(struct tty_struct *tty) +{ + unsigned long flags; + + spin_lock_irqsave(&tty->ctrl_lock, flags); + if (tty->link && tty->link->packet) { + tty->ctrl_status &= ~TIOCPKT_STOP; + tty->ctrl_status |= TIOCPKT_START; + wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); + } + spin_unlock_irqrestore(&tty->ctrl_lock, flags); +} + +static void pty_stop(struct tty_struct *tty) +{ + unsigned long flags; + + spin_lock_irqsave(&tty->ctrl_lock, flags); + if (tty->link && tty->link->packet) { + tty->ctrl_status &= ~TIOCPKT_START; + tty->ctrl_status |= TIOCPKT_STOP; + wake_up_interruptible_poll(&tty->link->read_wait, POLLIN); + } + spin_unlock_irqrestore(&tty->ctrl_lock, flags); +} + +/** * pty_common_install - set up the pty pair * @driver: the pty driver * @tty: the tty being instantiated @@ -471,6 +508,8 @@ static const struct tty_operations slave_pty_ops_bsd = { .set_termios = pty_set_termios, .cleanup = pty_cleanup, .resize = pty_resize, + .start = pty_start, + .stop = pty_stop, .remove = pty_remove }; @@ -646,6 +685,8 @@ static const struct tty_operations pty_unix98_ops = { .chars_in_buffer = pty_chars_in_buffer, .unthrottle = pty_unthrottle, .set_termios = pty_set_termios, + .start = pty_start, + .stop = pty_stop, .shutdown = pty_unix98_shutdown, .cleanup = pty_cleanup, }; |