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| author | Jiri Slaby <jslaby@suse.cz> | 2011-11-16 16:27:07 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@suse.de> | 2011-11-26 09:08:36 -0800 |
| commit | d21ada2ca367042fc5a1a11a2c2703e04c93211d (patch) | |
| tree | c5cfa9901cff8b37fcc7ff2cc6f2f278f3b8014a | |
| parent | 5a25cbde3ff3fafa1f48a00a37ed3fda278b5641 (diff) | |
| download | lwn-d21ada2ca367042fc5a1a11a2c2703e04c93211d.tar.gz lwn-d21ada2ca367042fc5a1a11a2c2703e04c93211d.zip | |
TTY: ldisc, allow waiting for ldisc arbitrarily long
commit df92d0561de364de53c42abc5d43e04ab6f326a5 upstream.
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@suse.cz>
Cc: Dave Young <hidave.darkstar@gmail.com>
Cc: Dave Jones <davej@redhat.com>
Cc: Ben Hutchings <ben@decadent.org.uk>
Cc: Dmitriy Matrosov <sgf.dma@gmail.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| -rw-r--r-- | 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 ef925d581713..363d5689a842 100644 --- a/drivers/tty/tty_ldisc.c +++ b/drivers/tty/tty_ldisc.c @@ -548,15 +548,16 @@ 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; @@ -666,7 +667,7 @@ 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); @@ -763,7 +764,7 @@ 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); |