Re: [PATCH v2 1/2] iio: hrtimer-trigger: Mark hrtimer to expire in hard interrupt context

[Jonathan Cameron <jic23@kernel.org>]

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