tty: add throttle/unthrottle helpers
Something Arjan suggested which allows us to clean up the code nicely
Signed-off-by: Alan Cox <alan@redhat.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c
index a6c2619..e5cd856 100644
--- a/drivers/bluetooth/hci_ldisc.c
+++ b/drivers/bluetooth/hci_ldisc.c
@@ -370,9 +370,7 @@
hu->hdev->stat.byte_rx += count;
spin_unlock(&hu->rx_lock);
- if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
- tty->ops->unthrottle)
- tty->ops->unthrottle(tty);
+ tty_unthrottle(tty);
}
static int hci_uart_register_dev(struct hci_uart *hu)
diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c
index abc93a9..19105ec 100644
--- a/drivers/char/n_tty.c
+++ b/drivers/char/n_tty.c
@@ -147,10 +147,8 @@
static void check_unthrottle(struct tty_struct *tty)
{
- if (tty->count &&
- test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
- tty->ops->unthrottle)
- tty->ops->unthrottle(tty);
+ if (tty->count)
+ tty_unthrottle(tty);
}
/**
@@ -982,12 +980,8 @@
* mode. We don't want to throttle the driver if we're in
* canonical mode and don't have a newline yet!
*/
- 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->ops->throttle)
- tty->ops->throttle(tty);
- }
+ if (tty->receive_room < TTY_THRESHOLD_THROTTLE)
+ tty_throttle(tty);
}
int is_ignored(int sig)
diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c
index c10d40c..b1a757a 100644
--- a/drivers/char/tty_ioctl.c
+++ b/drivers/char/tty_ioctl.c
@@ -67,6 +67,22 @@
EXPORT_SYMBOL(tty_driver_flush_buffer);
+void tty_throttle(struct tty_struct *tty)
+{
+ /* check TTY_THROTTLED first so it indicates our state */
+ if (!test_and_set_bit(TTY_THROTTLED, &tty->flags) &&
+ tty->ops->throttle)
+ tty->ops->throttle(tty);
+}
+EXPORT_SYMBOL(tty_throttle);
+
+void tty_unthrottle(struct tty_struct *tty)
+{
+ if (test_and_clear_bit(TTY_THROTTLED, &tty->flags) &&
+ tty->ops->unthrottle)
+ tty->ops->unthrottle(tty);
+}
+EXPORT_SYMBOL(tty_unthrottle);
/**
* tty_wait_until_sent - wait for I/O to finish
diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c
index 82a3626..9d57212 100644
--- a/drivers/net/hamradio/6pack.c
+++ b/drivers/net/hamradio/6pack.c
@@ -491,9 +491,7 @@
sixpack_decode(sp, buf, count1);
sp_put(sp);
- if (test_and_clear_bit(TTY_THROTTLED, &tty->flags)
- && tty->ops->unthrottle)
- tty->ops->unthrottle(tty);
+ tty_unthrottle(tty);
}
/*
diff --git a/drivers/net/hamradio/mkiss.c b/drivers/net/hamradio/mkiss.c
index ebcc5ad..6516603 100644
--- a/drivers/net/hamradio/mkiss.c
+++ b/drivers/net/hamradio/mkiss.c
@@ -936,9 +936,7 @@
}
mkiss_put(ax);
- if (test_and_clear_bit(TTY_THROTTLED, &tty->flags)
- && tty->ops->unthrottle)
- tty->ops->unthrottle(tty);
+ tty_unthrottle(tty);
}
/*
diff --git a/drivers/net/ppp_async.c b/drivers/net/ppp_async.c
index 1c4b7e3..f1a52de 100644
--- a/drivers/net/ppp_async.c
+++ b/drivers/net/ppp_async.c
@@ -361,9 +361,7 @@
if (!skb_queue_empty(&ap->rqueue))
tasklet_schedule(&ap->tsk);
ap_put(ap);
- if (test_and_clear_bit(TTY_THROTTLED, &tty->flags)
- && tty->ops->unthrottle)
- tty->ops->unthrottle(tty);
+ tty_unthrottle(tty);
}
static void
diff --git a/drivers/net/ppp_synctty.c b/drivers/net/ppp_synctty.c
index 48ed5fd..b8f0369 100644
--- a/drivers/net/ppp_synctty.c
+++ b/drivers/net/ppp_synctty.c
@@ -401,9 +401,7 @@
if (!skb_queue_empty(&ap->rqueue))
tasklet_schedule(&ap->tsk);
sp_put(ap);
- if (test_and_clear_bit(TTY_THROTTLED, &tty->flags)
- && tty->ops->unthrottle)
- tty->ops->unthrottle(tty);
+ tty_unthrottle(tty);
}
static void
diff --git a/include/linux/tty.h b/include/linux/tty.h
index c36a76d..7f7121f 100644
--- a/include/linux/tty.h
+++ b/include/linux/tty.h
@@ -303,6 +303,8 @@
extern int tty_chars_in_buffer(struct tty_struct *tty);
extern int tty_write_room(struct tty_struct *tty);
extern void tty_driver_flush_buffer(struct tty_struct *tty);
+extern void tty_throttle(struct tty_struct *tty);
+extern void tty_unthrottle(struct tty_struct *tty);
extern int is_current_pgrp_orphaned(void);
extern struct pid *tty_get_pgrp(struct tty_struct *tty);
diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h
index f80d73b..59f1c0b 100644
--- a/include/linux/tty_driver.h
+++ b/include/linux/tty_driver.h
@@ -100,6 +100,8 @@
* This routine notifies the tty driver that input buffers for
* the line discipline are close to full, and it should somehow
* signal that no more characters should be sent to the tty.
+ *
+ * Optional: Always invoke via tty_throttle();
*
* void (*unthrottle)(struct tty_struct * tty);
*
@@ -107,6 +109,8 @@
* that characters can now be sent to the tty without fear of
* overrunning the input buffers of the line disciplines.
*
+ * Optional: Always invoke via tty_unthrottle();
+ *
* void (*stop)(struct tty_struct *tty);
*
* This routine notifies the tty driver that it should stop