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[v1,5/5] iio:humidity:hts221: rearrange iio trigger get and register

Message ID 20220523183716.20360-1-ddrokosov@sberdevices.ru (mailing list archive)
State Superseded
Headers show
Series iio: treewide: rearrange iio trig get/register | expand

Commit Message

Dmitry Rokosov May 23, 2022, 6:36 p.m. UTC
IIO trigger interface function iio_trigger_get() should be called after
iio_trigger_register() (or its devm analogue) strictly, because of
iio_trigger_get() acquires module refcnt based on the trigger->owner
pointer, which is initialized inside iio_trigger_register() to
If this call order is wrong, the next iio_trigger_put() (from sysfs
callbacks or rmmod) will derefence "default" module refcnt, which is
completely incorrect.

Signed-off-by: Dmitry Rokosov <ddrokosov@sberdevices.ru>
 drivers/iio/humidity/hts221_buffer.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
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diff --git a/drivers/iio/humidity/hts221_buffer.c b/drivers/iio/humidity/hts221_buffer.c
index f29692b9d2db..66b32413cf5e 100644
--- a/drivers/iio/humidity/hts221_buffer.c
+++ b/drivers/iio/humidity/hts221_buffer.c
@@ -135,9 +135,12 @@  int hts221_allocate_trigger(struct iio_dev *iio_dev)
 	iio_trigger_set_drvdata(hw->trig, iio_dev);
 	hw->trig->ops = &hts221_trigger_ops;
+	err = devm_iio_trigger_register(hw->dev, hw->trig);
 	iio_dev->trig = iio_trigger_get(hw->trig);
-	return devm_iio_trigger_register(hw->dev, hw->trig);
+	return err;
 static int hts221_buffer_preenable(struct iio_dev *iio_dev)