diff options
| author | Josh Cartwright <joshc@ni.com> | 2016-10-13 10:44:33 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2017-01-09 08:21:56 +0100 |
| commit | 47090341ec97222f47c9ac7dc35b587b85bf1d0d (patch) | |
| tree | 5224188bdecf22b355cc6e037069043d6b7454c4 | |
| parent | c33e1abd2e31d08c96f512e1af09d874be9bcbfe (diff) | |
| download | linux-47090341ec97222f47c9ac7dc35b587b85bf1d0d.tar.gz linux-47090341ec97222f47c9ac7dc35b587b85bf1d0d.zip | |
sc16is7xx: Drop bogus use of IRQF_ONESHOT
commit 04da73803c05dc1150ccc31cbf93e8cd56679c09 upstream.
The use of IRQF_ONESHOT when registering an interrupt handler with
request_irq() is non-sensical.
Not only that, it also prevents the handler from being threaded when it
otherwise should be w/ IRQ_FORCED_THREADING is enabled. This causes the
following deadlock observed by Sean Nyekjaer on -rt:
Internal error: Oops - BUG: 0 [#1] PREEMPT SMP ARM
[..]
rt_spin_lock_slowlock from queue_kthread_work
queue_kthread_work from sc16is7xx_irq
sc16is7xx_irq [sc16is7xx] from handle_irq_event_percpu
handle_irq_event_percpu from handle_irq_event
handle_irq_event from handle_level_irq
handle_level_irq from generic_handle_irq
generic_handle_irq from mxc_gpio_irq_handler
mxc_gpio_irq_handler from mx3_gpio_irq_handler
mx3_gpio_irq_handler from generic_handle_irq
generic_handle_irq from __handle_domain_irq
__handle_domain_irq from gic_handle_irq
gic_handle_irq from __irq_svc
__irq_svc from rt_spin_unlock
rt_spin_unlock from kthread_worker_fn
kthread_worker_fn from kthread
kthread from ret_from_fork
Fixes: 9e6f4ca3e567 ("sc16is7xx: use kthread_worker for tx_work and irq")
Reported-by: Sean Nyekjaer <sean.nyekjaer@prevas.dk>
Signed-off-by: Josh Cartwright <joshc@ni.com>
Cc: linux-rt-users@vger.kernel.org
Cc: Jakub Kicinski <moorray3@wp.pl>
Cc: linux-serial@vger.kernel.org
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Julia Cartwright <julia@ni.com>
Acked-by: Jakub Kicinski <kubakici@wp.pl>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/tty/serial/sc16is7xx.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c index f36e6df2fa90..e086ea4d2997 100644 --- a/drivers/tty/serial/sc16is7xx.c +++ b/drivers/tty/serial/sc16is7xx.c @@ -1240,7 +1240,7 @@ static int sc16is7xx_probe(struct device *dev, /* Setup interrupt */ ret = devm_request_irq(dev, irq, sc16is7xx_irq, - IRQF_ONESHOT | flags, dev_name(dev), s); + flags, dev_name(dev), s); if (!ret) return 0; |