From 39c2e60f8c584c1b29b5c4375dd49df7995386bb Mon Sep 17 00:00:00 2001 From: Alan Cox Date: Wed, 30 Apr 2008 00:54:18 -0700 Subject: [PATCH] tty: add throttle/unthrottle helpers Something Arjan suggested which allows us to clean up the code nicely Signed-off-by: Alan Cox Cc: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- drivers/bluetooth/hci_ldisc.c | 4 +--- drivers/char/n_tty.c | 14 ++++---------- drivers/char/tty_ioctl.c | 16 ++++++++++++++++ drivers/net/hamradio/6pack.c | 4 +--- drivers/net/hamradio/mkiss.c | 4 +--- drivers/net/ppp_async.c | 4 +--- drivers/net/ppp_synctty.c | 4 +--- include/linux/tty.h | 2 ++ include/linux/tty_driver.h | 4 ++++ 9 files changed, 31 insertions(+), 25 deletions(-) diff --git a/drivers/bluetooth/hci_ldisc.c b/drivers/bluetooth/hci_ldisc.c index a6c2619ec78..e5cd856a2fe 100644 --- a/drivers/bluetooth/hci_ldisc.c +++ b/drivers/bluetooth/hci_ldisc.c @@ -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) diff --git a/drivers/char/n_tty.c b/drivers/char/n_tty.c index abc93a93dcd..19105ec203f 100644 --- a/drivers/char/n_tty.c +++ b/drivers/char/n_tty.c @@ -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) diff --git a/drivers/char/tty_ioctl.c b/drivers/char/tty_ioctl.c index c10d40c4c5c..b1a757a5ee2 100644 --- a/drivers/char/tty_ioctl.c +++ b/drivers/char/tty_ioctl.c @@ -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 diff --git a/drivers/net/hamradio/6pack.c b/drivers/net/hamradio/6pack.c index 82a36266dfc..9d5721287d6 100644 --- a/drivers/net/hamradio/6pack.c +++ b/drivers/net/hamradio/6pack.c @@ -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); } /* diff --git a/drivers/net/hamradio/mkiss.c b/drivers/net/hamradio/mkiss.c index ebcc5adee7c..65166035aca 100644 --- a/drivers/net/hamradio/mkiss.c +++ b/drivers/net/hamradio/mkiss.c @@ -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); } /* diff --git a/drivers/net/ppp_async.c b/drivers/net/ppp_async.c index 1c4b7e37912..f1a52def124 100644 --- a/drivers/net/ppp_async.c +++ b/drivers/net/ppp_async.c @@ -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 diff --git a/drivers/net/ppp_synctty.c b/drivers/net/ppp_synctty.c index 48ed5fdbfe1..b8f0369a71e 100644 --- a/drivers/net/ppp_synctty.c +++ b/drivers/net/ppp_synctty.c @@ -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 diff --git a/include/linux/tty.h b/include/linux/tty.h index c36a76da2ae..7f7121f9c96 100644 --- a/include/linux/tty.h +++ b/include/linux/tty.h @@ -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); diff --git a/include/linux/tty_driver.h b/include/linux/tty_driver.h index f80d73b690f..59f1c0bd8f9 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 -- 2.41.1