As a part of patch series about wrong trigger register() and get() calls order in the some IIO drivers trigger initialization path: https://lore.kernel.org/all/20220524181150.9240-1-ddrokosov@xxxxxxxxxxxxxx/ runtime WARN_ONCE() is added to alarm IIO driver authors who make such a mistake. When an IIO driver allocates a new IIO trigger, it should register it before calling the get() operation. In other words, each IIO driver must abide by IIO trigger alloc()/register()/get() calls order. Signed-off-by: Dmitry Rokosov <ddrokosov@xxxxxxxxxxxxxx> --- Changes: v1 -> v2: totally reworked the patch, used trig->list entry instead of trig->owner as driver registration indicator. It works perfectly for both builtin and built as a module drivers. v2 -> v3: changed WARN() call to WARN_ONCE() to avoid warn spamming during deferred probe() as Andy suggested. --- drivers/iio/industrialio-trigger.c | 2 ++ include/linux/iio/trigger.h | 5 +++++ 2 files changed, 7 insertions(+) diff --git a/drivers/iio/industrialio-trigger.c b/drivers/iio/industrialio-trigger.c index f504ed351b3e..d6277e72d515 100644 --- a/drivers/iio/industrialio-trigger.c +++ b/drivers/iio/industrialio-trigger.c @@ -581,6 +581,8 @@ struct iio_trigger *viio_trigger_alloc(struct device *parent, if (trig->name == NULL) goto free_descs; + INIT_LIST_HEAD(&trig->list); + trig->subirq_chip.name = trig->name; trig->subirq_chip.irq_mask = &iio_trig_subirqmask; trig->subirq_chip.irq_unmask = &iio_trig_subirqunmask; diff --git a/include/linux/iio/trigger.h b/include/linux/iio/trigger.h index 4c69b144677b..03b1d6863436 100644 --- a/include/linux/iio/trigger.h +++ b/include/linux/iio/trigger.h @@ -93,6 +93,11 @@ static inline void iio_trigger_put(struct iio_trigger *trig) static inline struct iio_trigger *iio_trigger_get(struct iio_trigger *trig) { get_device(&trig->dev); + + WARN_ONCE(list_empty(&trig->list), + "Getting non-registered iio trigger %s is prohibited\n", + trig->name); + __module_get(trig->owner); return trig; -- 2.36.0
