* [BUG RFC] iio: pressure: zpa2326: incorrect condition or inconsistent return handling
@ 2017-05-03 10:53 Nicholas Mc Guire
2017-05-03 11:42 ` Peter Meerwald-Stadler
0 siblings, 1 reply; 2+ messages in thread
From: Nicholas Mc Guire @ 2017-05-03 10:53 UTC (permalink / raw)
To: Jonathan Cameron
Cc: Hartmut Knaack, Lars-Peter Clausen, Peter Meerwald-Stadler,
simran singhal, Arnd Bergmann, Gregor Boirie, linux-iio,
linux-kernel, Nicholas Mc Guire
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)",
ret);
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) {
/*
--
2.1.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [BUG RFC] iio: pressure: zpa2326: incorrect condition or inconsistent return handling
2017-05-03 10:53 [BUG RFC] iio: pressure: zpa2326: incorrect condition or inconsistent return handling Nicholas Mc Guire
@ 2017-05-03 11:42 ` Peter Meerwald-Stadler
0 siblings, 0 replies; 2+ messages in thread
From: Peter Meerwald-Stadler @ 2017-05-03 11:42 UTC (permalink / raw)
To: Nicholas Mc Guire
Cc: Jonathan Cameron, Lars-Peter Clausen, simran singhal,
Gregor Boirie, linux-iio, linux-kernel
Hello,
> wait_for_completion_interruptible_timeout() returns -ERESTARTSYS, 0 or
> remaining time in jiffies (atleast 1), thus the if (ret != -ERESTARTSYS)
> case here is unreachable.
if is not unreachable, there is a ret = -ETIME above it
> 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.
the intention of the code is not very clear, I agree
"no one shot interrupt" should probably be printed for the -ETIME case,
i.e. when a timeout occurs
> Also wait_for_completion_interruptible_timeout() returns a long not int.
true
> 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)",
> ret);
>
> 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) {
> /*
>
--
Peter Meerwald-Stadler
Mobile: +43 664 24 44 418
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2017-05-03 11:42 ` Peter Meerwald-Stadler
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