diff options
| author | Paul Fulghum <paulkf@microgate.com> | 2006-06-28 04:26:47 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-06-28 14:59:05 -0700 |
| commit | 817d6d3bceaf34c99f5343820f9b9e6021f0655c (patch) | |
| tree | 651104833124262db46c2a372b7adb55289cd8dd /drivers/char/tty_io.c | |
| parent | e0ac4761fa52acda90f9f53819c81474b511e3af (diff) | |
[PATCH] remove TTY_DONT_FLIP
Remove TTY_DONT_FLIP tty flag. This flag was introduced in 2.1.X kernels
to prevent the N_TTY line discipline functions read_chan() and
n_tty_receive_buf() from running at the same time. 2.2.15 introduced
tty->read_lock to protect access to the N_TTY read buffer, which is the
only state requiring protection between these two functions.
The current TTY_DONT_FLIP implementation is broken for SMP, and is not
universally honored by drivers that send data directly to the line
discipline receive_buf function.
Because TTY_DONT_FLIP is not necessary, is broken in implementation, and is
not universally honored, it is removed.
Signed-off-by: Paul Fulghum <paulkf@microgate.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'drivers/char/tty_io.c')
| -rw-r--r-- | drivers/char/tty_io.c | 15 |
1 files changed, 2 insertions, 13 deletions
diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c index bd74e82d8a7..b846d87f2b5 100644 --- a/drivers/char/tty_io.c +++ b/drivers/char/tty_io.c @@ -784,11 +784,8 @@ restart: } clear_bit(TTY_LDISC, &tty->flags); - clear_bit(TTY_DONT_FLIP, &tty->flags); - if (o_tty) { + if (o_tty) clear_bit(TTY_LDISC, &o_tty->flags); - clear_bit(TTY_DONT_FLIP, &o_tty->flags); - } spin_unlock_irqrestore(&tty_ldisc_lock, flags); /* @@ -1955,7 +1952,6 @@ static void release_dev(struct file * filp) * race with the set_ldisc code path. */ clear_bit(TTY_LDISC, &tty->flags); - clear_bit(TTY_DONT_FLIP, &tty->flags); cancel_delayed_work(&tty->buf.work); /* @@ -2784,13 +2780,6 @@ static void flush_to_ldisc(void *private_) if (disc == NULL) /* !TTY_LDISC */ return; - if (test_bit(TTY_DONT_FLIP, &tty->flags)) { - /* - * Do it after the next timer tick: - */ - schedule_delayed_work(&tty->buf.work, 1); - goto out; - } spin_lock_irqsave(&tty->buf.lock, flags); while((tbuf = tty->buf.head) != NULL) { while ((count = tbuf->commit - tbuf->read) != 0) { @@ -2809,7 +2798,7 @@ static void flush_to_ldisc(void *private_) tty_buffer_free(tty, tbuf); } spin_unlock_irqrestore(&tty->buf.lock, flags); -out: + tty_ldisc_deref(disc); } |