[BUG RFC] iio: pressure: zpa2326: incorrect condition or inconsistent return handling

From: Nicholas Mc Guire
Date: Wed May 03 2017 - 06:55:26 EST

wait_for_completion_interruptible_timeout() returns -ERESTARTSYS, 0 or
remaining time in jiffies (atleast 1), thus the if (ret != -ERESTARTSYS)
case here is unreachable.

As it is not clear from the warn message if this should simply be changed
to if (ret == -ERESTARTSYS), this needs a review by someone that knows
the intent of this condition. In any case the current treatment of the
return value of wait_for_completion_interruptible_timeout() is inconsistent
with the specification of the same.

Also wait_for_completion_interruptible_timeout() returns a long not int.

Problem was introduced in commit 03b262f2bbf4 ("iio:pressure: initial zpa2326 barometer support")

drivers/iio/pressure/zpa2326.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/pressure/zpa2326.c b/drivers/iio/pressure/zpa2326.c
index e58a0ad..80ca6ec 100644
--- a/drivers/iio/pressure/zpa2326.c
+++ b/drivers/iio/pressure/zpa2326.c
@@ -872,35 +872,35 @@ static int zpa2326_wait_oneshot_completion(const struct iio_dev *indio_dev,

ret = wait_for_completion_interruptible_timeout(
&private->data_ready, ZPA2326_CONVERSION_JIFFIES);
if (ret > 0)
* Interrupt handler completed before timeout: return operation
* status.
return private->result;

/* Clear all interrupts just to be sure. */
regmap_read(private->regmap, ZPA2326_INT_SOURCE_REG, &val);

if (!ret)
/* Timed out. */
ret = -ETIME;

- if (ret != -ERESTARTSYS)
+ if (ret == -ERESTARTSYS)
zpa2326_warn(indio_dev, "no one shot interrupt occurred (%d)",

return ret;

static int zpa2326_init_managed_irq(struct device *parent,
struct iio_dev *indio_dev,
struct zpa2326_private *private,
int irq)
int err;

private->irq = irq;

if (irq <= 0) {