lkml.org 
[lkml]   [2022]   [Jun]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH v3] iio: trigger: warn about non-registered iio trigger getting attempt
Date
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@sberdevices.ru/

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@sberdevices.ru>
---
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
\
 
 \ /
  Last update: 2022-06-07 23:40    [W:0.059 / U:0.860 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site