Commit 39c2e60f authored by Alan Cox's avatar Alan Cox Committed by Linus Torvalds

tty: add throttle/unthrottle helpers

Something Arjan suggested which allows us to clean up the code nicely
Signed-off-by: default avatarAlan Cox <alan@redhat.com>
Cc: Arjan van de Ven <arjan@infradead.org>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 8cd64518
......@@ -370,9 +370,7 @@ static void hci_uart_tty_receive(struct tty_struct *tty, const u8 *data, char *f
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)
......
......@@ -147,10 +147,8 @@ static void put_tty_queue(unsigned char c, struct tty_struct *tty)
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 @@ 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 (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)
......
......@@ -67,6 +67,22 @@ void tty_driver_flush_buffer(struct tty_struct *tty)
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
......
......@@ -491,9 +491,7 @@ static void sixpack_receive_buf(struct tty_struct *tty,
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);
}
/*
......
......@@ -936,9 +936,7 @@ static void mkiss_receive_buf(struct tty_struct *tty, const unsigned char *cp,
}
mkiss_put(ax);
if (test_and_clear_bit(TTY_THROTTLED, &tty->flags)
&& tty->ops->unthrottle)
tty->ops->unthrottle(tty);
tty_unthrottle(tty);
}
/*
......
......@@ -361,9 +361,7 @@ ppp_asynctty_receive(struct tty_struct *tty, const unsigned char *buf,
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
......
......@@ -401,9 +401,7 @@ ppp_sync_receive(struct tty_struct *tty, const unsigned char *buf,
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
......
......@@ -303,6 +303,8 @@ extern int tty_put_char(struct tty_struct *tty, unsigned char c);
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);
......
......@@ -101,12 +101,16 @@
* 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);
*
* This routine notifies the tty drivers that it should signals
* 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
......
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