Hi Jonathan, On Monday, 21 September 2020, 11:57:03 CEST, Jonathan Cameron wrote: > On Mon, 21 Sep 2020 09:17:26 +0200 > > Christian Eggers <ceggers@xxxxxxx> wrote: > > Tested together with > > > > - iio: Fix: Do not poll the driver again if try_reenable() callback > > returns non 0. and > > - iio:trigger: rename try_reenable() to reenable() plus return void > > > > on latest mainline (without PREEMPT_RT). The original WARN_ONCE() in > > kernel/irq/handle.c:159 was not raised anymore. But even without the > > current patches, this warning is not shown (as this problem only applies > > to -RT). > > > > Currently I haven't ported a RT kernel > 5.4 for my board, so I cannot > > check with current RT. On 5.4. there the patches seem not to work fully > > as kernel/timer/hrtimer.c is not up to date enough. > > > > Sorry for being not very helpful... > > Thanks for at least trying! I've just ported my BSP to v5.9-rc7-rt10. It looks like your patch misses one additional change in iio_trig_hrtimer_set_state(): - hrtimer_start(&trig_info->timer, trig_info->period, - HRTIMER_MODE_REL); + hrtimer_start(&trig_info->timer, trig_info->period, + HRTIMER_MODE_REL_HARD); Without this, WARN_ON_ONCE() in kernel/time/hrtimer.c:1133 will be hit: WARN_ON_ONCE(!(mode & HRTIMER_MODE_HARD) ^ !timer->is_hard); So the mode HRTIMER_MODE_REL_HARD is required for hrtimer_init() (will be stored in timer->is_hard) and for hrtimer_start(). Best regards Christian
