[PATCH 1/3] iio: st_sensors: Init trigger before irq request

[Crestez Dan Leonard <leonard.crestez@intel.com>]

This fixes a possible race where an interrupt arrives before complete
initialization and crashes because iio_trigger_get_drvdata returns NULL.

Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Giuseppe Barba <giuseppe.barba@st.com>
Cc: Denis Ciocca <denis.ciocca@st.com>
Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
---
I ran into this while breaking the driver. But since the interrupt line can be
shared the handler should always be able to accept and ignore a call.

 drivers/iio/common/st_sensors/st_sensors_trigger.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/iio/common/st_sensors/st_sensors_trigger.c b/drivers/iio/common/st_sensors/st_sensors_trigger.c
index 98bd5b3..7c2e6ab 100644
--- a/drivers/iio/common/st_sensors/st_sensors_trigger.c
+++ b/drivers/iio/common/st_sensors/st_sensors_trigger.c
@@ -89,6 +89,10 @@ int st_sensors_allocate_trigger(struct iio_dev *indio_dev,
 		return -ENOMEM;
 	}
 
+	iio_trigger_set_drvdata(sdata->trig, indio_dev);
+	sdata->trig->ops = trigger_ops;
+	sdata->trig->dev.parent = sdata->dev;
+
 	irq = sdata->get_irq_data_ready(indio_dev);
 	irq_trig = irqd_get_trigger_type(irq_get_irq_data(irq));
 	/*
@@ -150,10 +154,6 @@ int st_sensors_allocate_trigger(struct iio_dev *indio_dev,
 		goto iio_trigger_free;
 	}
 
-	iio_trigger_set_drvdata(sdata->trig, indio_dev);
-	sdata->trig->ops = trigger_ops;
-	sdata->trig->dev.parent = sdata->dev;
-
 	err = iio_trigger_register(sdata->trig);
 	if (err < 0) {
 		dev_err(&indio_dev->dev, "failed to register iio trigger.\n");
-- 
2.5.5