[PATCH 1/2] iio: itg3200: Call iio_trigger_notify_done() on error

[PATCH 1/2] iio: itg3200: Call iio_trigger_notify_done() on error

[Lars-Peter Clausen]

IIO trigger handlers must call iio_trigger_notify_done() when done. This
must be done even when an error occurred. Otherwise the trigger will be
seen as busy indefinitely and the trigger handler will never be called
again.

The itg3200 driver neglects to call iio_trigger_notify_done() when there is
an error reading the gyro data. Fix this by making sure that
iio_trigger_notify_done() is included in the error exit path.

Fixes: 9dbf091da080 ("iio: gyro: Add itg3200")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
---
 drivers/iio/gyro/itg3200_buffer.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/gyro/itg3200_buffer.c b/drivers/iio/gyro/itg3200_buffer.c
index 04dd6a7969ea..4cfa0d439560 100644
--- a/drivers/iio/gyro/itg3200_buffer.c
+++ b/drivers/iio/gyro/itg3200_buffer.c
@@ -61,9 +61,9 @@ static irqreturn_t itg3200_trigger_handler(int irq, void *p)
 
 	iio_push_to_buffers_with_timestamp(indio_dev, &scan, pf->timestamp);
 
+error_ret:
 	iio_trigger_notify_done(indio_dev->trig);
 
-error_ret:
 	return IRQ_HANDLED;
 }
 
-- 
2.20.1

[PATCH 2/2] iio: ad7768-1: Call iio_trigger_notify_done() on error

[Lars-Peter Clausen]

IIO trigger handlers must call iio_trigger_notify_done() when done. This
must be done even when an error occurred. Otherwise the trigger will be
seen as busy indefinitely and the trigger handler will never be called
again.

The ad7768-1 driver neglects to call iio_trigger_notify_done() when there
is an error reading the converter data. Fix this by making sure that
iio_trigger_notify_done() is included in the error exit path.

Fixes: a5f8c7da3dbe ("iio: adc: Add AD7768-1 ADC basic support")
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
---
 drivers/iio/adc/ad7768-1.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c
index 2c5c8a3672b2..aa42ba759fa1 100644
--- a/drivers/iio/adc/ad7768-1.c
+++ b/drivers/iio/adc/ad7768-1.c
@@ -480,8 +480,8 @@ static irqreturn_t ad7768_trigger_handler(int irq, void *p)
 	iio_push_to_buffers_with_timestamp(indio_dev, &st->data.scan,
 					   iio_get_time_ns(indio_dev));
 
-	iio_trigger_notify_done(indio_dev->trig);
 err_unlock:
+	iio_trigger_notify_done(indio_dev->trig);
 	mutex_unlock(&st->lock);
 
 	return IRQ_HANDLED;
-- 
2.20.1

Re: [PATCH 2/2] iio: ad7768-1: Call iio_trigger_notify_done() on error

[Jonathan Cameron]

On Mon,  1 Nov 2021 15:40:55 +0100
Lars-Peter Clausen <lars@metafoo.de> wrote:

> IIO trigger handlers must call iio_trigger_notify_done() when done. This
> must be done even when an error occurred. Otherwise the trigger will be
> seen as busy indefinitely and the trigger handler will never be called
> again.
> 
> The ad7768-1 driver neglects to call iio_trigger_notify_done() when there
> is an error reading the converter data. Fix this by making sure that
> iio_trigger_notify_done() is included in the error exit path.
> 
> Fixes: a5f8c7da3dbe ("iio: adc: Add AD7768-1 ADC basic support")
> Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>

Hi Lars,

I've always meant to have a hard think about what we 'should' do in the event
of an error in one of these trigger handlers.   Definitely don't want to get
stuck so these patches make sense, but I'd also at somepoint like to explore
if we should stop the device capture and do something like poison the kfifo
output so that we know it was broken. 

Anyhow, a discussion for another day.

Applied these two to the fixes-togreg branch of iio.git and marked for stable.

Thanks,

Jonathan

> ---
>  drivers/iio/adc/ad7768-1.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/iio/adc/ad7768-1.c b/drivers/iio/adc/ad7768-1.c
> index 2c5c8a3672b2..aa42ba759fa1 100644
> --- a/drivers/iio/adc/ad7768-1.c
> +++ b/drivers/iio/adc/ad7768-1.c
> @@ -480,8 +480,8 @@ static irqreturn_t ad7768_trigger_handler(int irq, void *p)
>  	iio_push_to_buffers_with_timestamp(indio_dev, &st->data.scan,
>  					   iio_get_time_ns(indio_dev));
>  
> -	iio_trigger_notify_done(indio_dev->trig);
>  err_unlock:
> +	iio_trigger_notify_done(indio_dev->trig);
>  	mutex_unlock(&st->lock);
>  
>  	return IRQ_HANDLED;