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author | Peter Hurley <peter@hurleysoftware.com> | 2013-06-15 09:14:33 -0400 |
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committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-07-23 16:43:02 -0700 |
commit | 6367ca72f1fad60de7ef607e10a999ed86ca6a8b (patch) | |
tree | 6807f6f01d124a8b203fc4c4d57ae1c8ae71f236 /drivers/tty/n_tty.c | |
parent | 9a4aec2dd5b54606b3508e0e064750f516009650 (diff) | |
download | op-kernel-dev-6367ca72f1fad60de7ef607e10a999ed86ca6a8b.zip op-kernel-dev-6367ca72f1fad60de7ef607e10a999ed86ca6a8b.tar.gz |
n_tty: Factor throttle/unthrottle into helper functions
Prepare for special handling of pty throttle/unthrottle; factor
flow control into helper functions.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/n_tty.c')
-rw-r--r-- | drivers/tty/n_tty.c | 81 |
1 files changed, 46 insertions, 35 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 9ec0c68..9e13c80 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -214,6 +214,50 @@ static ssize_t chars_in_buffer(struct tty_struct *tty) return n; } +static inline void n_tty_check_throttle(struct tty_struct *tty) +{ + /* + * Check the remaining room for the input canonicalization + * mode. We don't want to throttle the driver if we're in + * canonical mode and don't have a newline yet! + */ + while (1) { + int throttled; + tty_set_flow_change(tty, TTY_THROTTLE_SAFE); + if (receive_room(tty) >= TTY_THRESHOLD_THROTTLE) + break; + throttled = tty_throttle_safe(tty); + if (!throttled) + break; + } + __tty_set_flow_change(tty, 0); +} + +static inline void n_tty_check_unthrottle(struct tty_struct *tty) +{ + /* If there is enough space in the read buffer now, let the + * low-level driver know. We use chars_in_buffer() to + * check the buffer, as it now knows about canonical mode. + * Otherwise, if the driver is throttled and the line is + * longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode, + * we won't get any more characters. + */ + + while (1) { + int unthrottled; + tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE); + if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE) + break; + if (!tty->count) + break; + n_tty_set_room(tty); + unthrottled = tty_unthrottle_safe(tty); + if (!unthrottled) + break; + } + __tty_set_flow_change(tty, 0); +} + /** * put_tty_queue - add character to tty * @c: character @@ -1508,21 +1552,7 @@ static void __receive_buf(struct tty_struct *tty, const unsigned char *cp, wake_up_interruptible(&tty->read_wait); } - /* - * Check the remaining room for the input canonicalization - * mode. We don't want to throttle the driver if we're in - * canonical mode and don't have a newline yet! - */ - while (1) { - int throttled; - tty_set_flow_change(tty, TTY_THROTTLE_SAFE); - if (receive_room(tty) >= TTY_THRESHOLD_THROTTLE) - break; - throttled = tty_throttle_safe(tty); - if (!throttled) - break; - } - __tty_set_flow_change(tty, 0); + n_tty_check_throttle(tty); } static void n_tty_receive_buf(struct tty_struct *tty, const unsigned char *cp, @@ -2069,26 +2099,7 @@ do_it_again: } } - /* If there is enough space in the read buffer now, let the - * low-level driver know. We use chars_in_buffer() to - * check the buffer, as it now knows about canonical mode. - * Otherwise, if the driver is throttled and the line is - * longer than TTY_THRESHOLD_UNTHROTTLE in canonical mode, - * we won't get any more characters. - */ - while (1) { - int unthrottled; - tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE); - if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE) - break; - if (!tty->count) - break; - n_tty_set_room(tty); - unthrottled = tty_unthrottle_safe(tty); - if (!unthrottled) - break; - } - __tty_set_flow_change(tty, 0); + n_tty_check_unthrottle(tty); if (b - buf >= minimum) break; |