| Message ID | 20201117103751.16131-1-lars@metafoo.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2,1/2] iio: hrtimer-trigger: Mark hrtimer to expire in hard interrupt context | expand |
On 2020-11-17 11:37:50 [+0100], Lars-Peter Clausen wrote: > 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 <ceggers@arri.de> > Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> If I remember correctly, this routine should only be used to poll the primary handler. There were patches for the "other" possible things that might happen so Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> for both. Sebastian
On Tue, 17 Nov 2020 14:03:01 +0100 Sebastian Andrzej Siewior <bigeasy@linutronix.de> wrote: > On 2020-11-17 11:37:50 [+0100], Lars-Peter Clausen wrote: > > 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 <ceggers@arri.de> > > Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> > > If I remember correctly, this routine should only be used to poll the > primary handler. There were patches for the "other" possible things that > might happen so > > Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> I've applied them both to the fixes-togreg branch fo iio.git but not marked them for stable. If you want them in specific stable releases then please request them explicitly after they've merged. Thanks, Jonathan > > for both. > > Sebastian
diff --git a/drivers/iio/trigger/iio-trig-hrtimer.c b/drivers/iio/trigger/iio-trig-hrtimer.c index f59bf8d58586..410de837d041 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;
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 <ceggers@arri.de> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de> --- Changes since v1: * Also pass HRTIMER_MODE_REL_HARD to hrtimer_start(). --- drivers/iio/trigger/iio-trig-hrtimer.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)