From: Jiri Slaby <jslaby@xxxxxxx>
To fix a nasty bug in ldisc hup vs. reinit we need to wait infinitely
long for ldisc to be gone. So here we add a parameter to
tty_ldisc_wait_idle to allow that.
This is only a preparation for the real fix which is done in the
following patches.
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
Cc: Dave Young <hidave.darkstar@xxxxxxxxx>
Cc: Dave Jones <davej@xxxxxxxxxx>
Cc: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
Cc: Dmitriy Matrosov <sgf.dma@xxxxxxxxx>
Cc: Alan Cox <alan@xxxxxxxxxxxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
drivers/tty/tty_ldisc.c | 11 ++++++-----
1 files changed, 6 insertions(+), 5 deletions(-)
diff --git a/drivers/tty/tty_ldisc.c b/drivers/tty/tty_ldisc.c
index 512c49f..534d176 100644
--- a/drivers/tty/tty_ldisc.c
+++ b/drivers/tty/tty_ldisc.c
@@ -547,15 +547,16 @@ static void tty_ldisc_flush_works(struct tty_struct *tty)
/**
* tty_ldisc_wait_idle - wait for the ldisc to become idle
* @tty: tty to wait for
+ * @timeout: for how long to wait at most
*
* Wait for the line discipline to become idle. The discipline must
* have been halted for this to guarantee it remains idle.
*/
-static int tty_ldisc_wait_idle(struct tty_struct *tty)
+static int tty_ldisc_wait_idle(struct tty_struct *tty, long timeout)
{
- int ret;
+ long ret;
ret = wait_event_timeout(tty_ldisc_idle,
- atomic_read(&tty->ldisc->users) == 1, 5 * HZ);
+ atomic_read(&tty->ldisc->users) == 1, timeout);
if (ret < 0)
return ret;
return ret > 0 ? 0 : -EBUSY;
@@ -665,7 +666,7 @@ int tty_set_ldisc(struct tty_struct *tty, int ldisc)
tty_ldisc_flush_works(tty);
- retval = tty_ldisc_wait_idle(tty);
+ retval = tty_ldisc_wait_idle(tty, 5 * HZ);
tty_lock();
mutex_lock(&tty->ldisc_mutex);
@@ -762,7 +763,7 @@ static int tty_ldisc_reinit(struct tty_struct *tty, int ldisc)
if (IS_ERR(ld))
return -1;
- WARN_ON_ONCE(tty_ldisc_wait_idle(tty));
+ WARN_ON_ONCE(tty_ldisc_wait_idle(tty, 5 * HZ));
tty_ldisc_close(tty, tty->ldisc);
tty_ldisc_put(tty->ldisc);
--
1.7.7.3
--
To unsubscribe from this list: send the line "unsubscribe linux-serial" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
