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| author | Peter Hurley | 2013-03-11 21:44:21 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2013-03-19 00:32:46 +0100 |
| commit | 21622939fc452c7fb739464b8e49368c3ceaa0ee (patch) | |
| tree | c96d6a137611e9d976a4d391a48c94f5267db7ff /drivers/tty/n_tty.c | |
| parent | tty: ifx6x60: Remove unused suspend/resume callbacks (diff) | |
| download | kernel-qcow2-linux-21622939fc452c7fb739464b8e49368c3ceaa0ee.tar.gz kernel-qcow2-linux-21622939fc452c7fb739464b8e49368c3ceaa0ee.tar.xz kernel-qcow2-linux-21622939fc452c7fb739464b8e49368c3ceaa0ee.zip | |
tty: Add diagnostic for halted line discipline
Flip buffer work must not be scheduled by the line discipline
after the line discipline has been halted; issue warning.
Note: drivers can still schedule flip buffer work.
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 | 8 |
1 files changed, 8 insertions, 0 deletions
diff --git a/drivers/tty/n_tty.c b/drivers/tty/n_tty.c index 68865d9af8a0..16793eccc6ae 100644 --- a/drivers/tty/n_tty.c +++ b/drivers/tty/n_tty.c @@ -153,6 +153,12 @@ static void n_tty_set_room(struct tty_struct *tty) if (left && !old_left) { WARN_RATELIMIT(tty->port->itty == NULL, "scheduling with invalid itty\n"); + /* see if ldisc has been killed - if so, this means that + * even though the ldisc has been halted and ->buf.work + * cancelled, ->buf.work is about to be rescheduled + */ + WARN_RATELIMIT(test_bit(TTY_LDISC_HALTED, &tty->flags), + "scheduling buffer work for halted ldisc\n"); schedule_work(&tty->port->buf.work); } } @@ -1624,6 +1630,8 @@ static int n_tty_open(struct tty_struct *tty) goto err_free_bufs; tty->disc_data = ldata; + /* indicate buffer work may resume */ + clear_bit(TTY_LDISC_HALTED, &tty->flags); reset_buffer_flags(tty); tty_unthrottle(tty); ldata->column = 0; |