diff options
| author | Peter Hurley <peter@hurleysoftware.com> | 2013-06-15 18:04:27 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-07-24 04:02:22 +0400 |
| commit | bc5b1ec5860a9bf52842be4a3a9d96e19f06c11d (patch) | |
| tree | 85a134a54a6c82f15ef3124d8ad6adf179ffd88b /drivers/tty/n_tty.c | |
| parent | cbfd0340ae1993378fd47179db949e050e16e697 (diff) | |
| download | linux-bc5b1ec5860a9bf52842be4a3a9d96e19f06c11d.tar.xz | |
n_tty: Only flush echo output if actually output
Don't have the driver flush received echoes if no echoes were
actually output.
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 | 18 |
1 files changed, 10 insertions, 8 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 20983afb6086..59f3f10f37f3 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -646,14 +646,14 @@ break_out: * Locking: callers must hold output_lock */ -static void __process_echoes(struct tty_struct *tty) +static size_t __process_echoes(struct tty_struct *tty) { struct n_tty_data *ldata = tty->disc_data; - int space, nr; + int space, old_space; size_t tail; unsigned char c; - space = tty_write_room(tty); + old_space = space = tty_write_room(tty); tail = ldata->echo_tail; nr = ldata->echo_commit - ldata->echo_tail; @@ -785,12 +785,13 @@ static void __process_echoes(struct tty_struct *tty) } ldata->echo_tail = tail; + return old_space - space; } static void commit_echoes(struct tty_struct *tty) { struct n_tty_data *ldata = tty->disc_data; - size_t nr, old; + size_t nr, old, echoed; size_t head; head = ldata->echo_head; @@ -805,25 +806,26 @@ static void commit_echoes(struct tty_struct *tty) mutex_lock(&ldata->output_lock); ldata->echo_commit = head; - __process_echoes(tty); + echoed = __process_echoes(tty); mutex_unlock(&ldata->output_lock); - if (tty->ops->flush_chars) + if (echoed && tty->ops->flush_chars) tty->ops->flush_chars(tty); } static void process_echoes(struct tty_struct *tty) { struct n_tty_data *ldata = tty->disc_data; + size_t echoed; if (!L_ECHO(tty) || ldata->echo_commit == ldata->echo_tail) return; mutex_lock(&ldata->output_lock); - __process_echoes(tty); + echoed = __process_echoes(tty); mutex_unlock(&ldata->output_lock); - if (tty->ops->flush_chars) + if (echoed && tty->ops->flush_chars) tty->ops->flush_chars(tty); } |