From 0178297c1e6898e2197fe169ef3be723e019b971 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Tue, 17 Nov 2020 11:37:50 +0100 Subject: [PATCH] iio: hrtimer-trigger: Mark hrtimer to expire in hard interrupt context On PREEMPT_RT enabled kernels unmarked hrtimers are moved into soft interrupt expiry mode by default. The IIO hrtimer-trigger needs to run in hard interrupt context since it will end up calling generic_handle_irq() which has the requirement to run in hard interrupt context. Explicitly specify that the timer needs to run in hard interrupt context by using the HRTIMER_MODE_REL_HARD flag. Fixes: f5c2f0215e36 ("hrtimer: Move unmarked hrtimers to soft interrupt expiry on RT") Reported-by: Christian Eggers Signed-off-by: Lars-Peter Clausen Acked-by: Sebastian Andrzej Siewior Link: https://lore.kernel.org/r/20201117103751.16131-1-lars@metafoo.de Signed-off-by: Jonathan Cameron --- drivers/iio/trigger/iio-trig-hrtimer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/iio/trigger/iio-trig-hrtimer.c b/drivers/iio/trigger/iio-trig-hrtimer.c index f59bf8d5..410de83 100644 --- a/drivers/iio/trigger/iio-trig-hrtimer.c +++ b/drivers/iio/trigger/iio-trig-hrtimer.c @@ -102,7 +102,7 @@ static int iio_trig_hrtimer_set_state(struct iio_trigger *trig, bool state) if (state) hrtimer_start(&trig_info->timer, trig_info->period, - HRTIMER_MODE_REL); + HRTIMER_MODE_REL_HARD); else hrtimer_cancel(&trig_info->timer); @@ -132,7 +132,7 @@ static struct iio_sw_trigger *iio_trig_hrtimer_probe(const char *name) trig_info->swt.trigger->ops = &iio_hrtimer_trigger_ops; trig_info->swt.trigger->dev.groups = iio_hrtimer_attr_groups; - hrtimer_init(&trig_info->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); + hrtimer_init(&trig_info->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL_HARD); trig_info->timer.function = iio_hrtimer_trig_handler; trig_info->sampling_frequency = HRTIMER_DEFAULT_SAMPLING_FREQUENCY; -- 2.7.4