Messages in this thread | | | Subject | Re: [PATCH] sc16is7xx: drop bogus use of IRQF_ONESHOT | From | Sean Nyekjær <> | Date | Tue, 8 Mar 2016 13:43:27 +0100 |
| |
On 2016-02-18 18:26, Josh Cartwright wrote: > 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+0x18/0x74) > queue_kthread_work) from (sc16is7xx_irq+0x10/0x18 [sc16is7xx]) > sc16is7xx_irq [sc16is7xx]) from (handle_irq_event_percpu+0x70/0x158) > handle_irq_event_percpu) from (handle_irq_event+0x68/0xa8) > handle_irq_event) from (handle_level_irq+0x10c/0x184) > handle_level_irq) from (generic_handle_irq+0x2c/0x3c) > generic_handle_irq) from (mxc_gpio_irq_handler+0x3c/0x108) > mxc_gpio_irq_handler) from (mx3_gpio_irq_handler+0x80/0xcc) > mx3_gpio_irq_handler) from (generic_handle_irq+0x2c/0x3c) > generic_handle_irq) from (__handle_domain_irq+0x7c/0xe8) > __handle_domain_irq) from (gic_handle_irq+0x24/0x5c) > gic_handle_irq) from (__irq_svc+0x40/0x88) > (__irq_svc) from (rt_spin_unlock+0x1c/0x68) > (rt_spin_unlock) from (kthread_worker_fn+0x104/0x17c) > (kthread_worker_fn) from (kthread+0xd0/0xe8) > (kthread) from (ret_from_fork+0x14/0x2c) > > Reported-by: Sean Nyekjaer <sean.nyekjaer@prevas.dk> > Fixes: 9e6f4ca3e567 ("sc16is7xx: use kthread_worker for tx_work and irq") > Cc: stable@vger.kernel.org # v4.1+ > Signed-off-by: Josh Cartwright <joshc@ni.com> > --- > drivers/tty/serial/sc16is7xx.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c > index e78fa99..1bb5c0e 100644 > --- a/drivers/tty/serial/sc16is7xx.c > +++ b/drivers/tty/serial/sc16is7xx.c > @@ -1257,7 +1257,7 @@ 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; > Is PATCH this dropped? It clearly fixes the irq when running with RT patches :-)
/Sean
| |