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-rw-r--r--drivers/tty/pty.c41
-rw-r--r--drivers/tty/tty_io.c31
2 files changed, 45 insertions, 27 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,
};
diff --git a/drivers/tty/tty_io.c b/drivers/tty/tty_io.c
index b8ddfef6b5d8..c249ff1d51ce 100644
--- a/drivers/tty/tty_io.c
+++ b/drivers/tty/tty_io.c
@@ -908,8 +908,7 @@ void no_tty(void)
* stop_tty - propagate flow control
* @tty: tty to stop
*
- * Perform flow control to the driver. For PTY/TTY pairs we
- * must also propagate the TIOCKPKT status. May be called
+ * Perform flow control to the driver. May be called
* on an already stopped device and will not re-call the driver
* method.
*
@@ -919,24 +918,14 @@ void no_tty(void)
* but not always.
*
* Locking:
- * ctrl_lock
* flow_lock
*/
void __stop_tty(struct tty_struct *tty)
{
- unsigned long flags;
-
if (tty->stopped)
return;
tty->stopped = 1;
- 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);
if (tty->ops->stop)
(tty->ops->stop)(tty);
}
@@ -955,33 +944,21 @@ EXPORT_SYMBOL(stop_tty);
* start_tty - propagate flow control
* @tty: tty to start
*
- * Start a tty that has been stopped if at all possible. Perform
- * any necessary wakeups and propagate the TIOCPKT status. If this
- * is the tty was previous stopped and is being started then the
- * driver start method is invoked and the line discipline woken.
+ * Start a tty that has been stopped if at all possible. If this
+ * tty was previous stopped and is now being started, the driver
+ * start method is invoked and the line discipline woken.
*
* Locking:
- * ctrl_lock
* flow_lock
*/
void __start_tty(struct tty_struct *tty)
{
- unsigned long flags;
-
if (!tty->stopped || tty->flow_stopped)
return;
tty->stopped = 0;
- 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);
if (tty->ops->start)
(tty->ops->start)(tty);
- /* If we have a running line discipline it may need kicking */
tty_wakeup(tty);
}