Hi Lars
On Monday, 3 August 2020, 08:52:54 CEST, Lars-Peter Clausen wrote:
On 8/3/20 8:44 AM, Christian Eggers wrote:
... is my patch sufficient, or would you prefer a different solution?
The code in normal upstream is correct, there is no need to patch it since iio_sysfs_trigger_work() always runs with IRQs disabled.
Are you using a non-upstream kernel? Maybe a RT kernel?
I use v5.4.<almost-latest>-rt
That explains it. Have a look at 0200-irqwork-push-most-work-into-softirq-context.patch.
The right fix for this issue is to add the following snippet to the RT patchset.
diff --git a/drivers/iio/trigger/iio-trig-sysfs.c b/drivers/iio/trigger/iio-trig-sysfs.c --- a/drivers/iio/trigger/iio-trig-sysfs.c +++ b/drivers/iio/trigger/iio-trig-sysfs.c @@ -161,6 +161,7 @@ static int iio_sysfs_trigger_probe(int id) iio_trigger_set_drvdata(t->trig, t);
init_irq_work(&t->work, iio_sysfs_trigger_work);
t->work.flags = IRQ_WORK_HARD_IRQ;
ret = iio_trigger_register(t->trig); if (ret)
I can confirm that this works for iio-trig-sysfs on 5.4.54-rt32. Currently I do not use iio-trig-hrtimer, but if I remember correctly, the problem was also present there.
Do you want to apply your patch for mainline? In contrast to v5.4, IRQ_WORK_HARD_IRQ is already available there (moved to smp_types.h). Unfortunately I cannot test it on mainline for now, as my BSP stuff is not ported yet.
Best regards Christian