diff options
| author | Peter Hurley | 2013-06-15 09:14:18 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2013-07-23 16:43:00 -0700 |
| commit | a19d0c6a9166fe3d8bb1575b64f28590206148d9 (patch) | |
| tree | 5ea4e042a5883a7508b7ad044d5c82208c862dc7 | |
| parent | 32f13521ca68bc624ff6effc77f308a52b038bf0 (diff) | |
n_tty: Split n_tty_chars_in_buffer() for reader-only interface
N_TTY .chars_in_buffer() method requires serialized access if
the current thread is not the single-consumer, n_tty_read().
Separate the internal interface; prepare for lockless read-side.
Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/n_tty.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 74dcedd06a8b..594a3c19882b 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -277,7 +277,7 @@ static void n_tty_flush_buffer(struct tty_struct *tty) * Locking: read_lock */ -static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty) +static ssize_t chars_in_buffer(struct tty_struct *tty) { struct n_tty_data *ldata = tty->disc_data; unsigned long flags; @@ -295,6 +295,11 @@ static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty) return n; } +static ssize_t n_tty_chars_in_buffer(struct tty_struct *tty) +{ + return chars_in_buffer(tty); +} + /** * is_utf8_continuation - utf8 multibyte check * @c: byte to check @@ -2032,7 +2037,7 @@ do_it_again: } /* If there is enough space in the read buffer now, let the - * low-level driver know. We use n_tty_chars_in_buffer() to + * 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, @@ -2040,7 +2045,7 @@ do_it_again: */ while (1) { tty_set_flow_change(tty, TTY_UNTHROTTLE_SAFE); - if (n_tty_chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE) + if (chars_in_buffer(tty) > TTY_THRESHOLD_UNTHROTTLE) break; if (!tty->count) break; |