Re: [tip: irq/core] genirq: Warn about using IRQF_ONESHOT without a threaded handler

[David Lechner <dlechner@baylibre.com>]

On 2/3/26 2:38 AM, Sebastian Andrzej Siewior wrote:
> On 2026-02-03 00:27:40 [+0100], Bert Karwatzki wrote:
>>
>> The warning appears because iio_triggered_buffer_setup_ext() (in 
>> drivers/iio/buffer/industrialio-triggered-buffer.c) is called with thread = NULL
>> during the probe of the iio device and calls iio_alloc_pollfunc()
>> (in drivers/iio/industrialio-trigger.c) with thread = NULL and type = IRQF_ONESHOT.
>>
>> A simple fix could be this:
>>
>> diff --git a/drivers/iio/buffer/industrialio-triggered-buffer.c b/drivers/iio/buffer/industrialio-triggered-buffer.c
>> index 9bf75dee7ff8..40eea3a44724 100644
>> --- a/drivers/iio/buffer/industrialio-triggered-buffer.c
>> +++ b/drivers/iio/buffer/industrialio-triggered-buffer.c
>> @@ -64,7 +64,7 @@ int iio_triggered_buffer_setup_ext(struct iio_dev *indio_dev,
>>  
>>         indio_dev->pollfunc = iio_alloc_pollfunc(h,
>>                                                  thread,
>> -                                                IRQF_ONESHOT,
>> +                                                thread ? IRQF_ONESHOT : 0,
>>                                                  indio_dev,
>>                                                  "%s_consumer%d",
>>                                                  indio_dev->name,
>>
>>
>> Are there any problems with this?
> 
> Urgh. Haven't seen those.
> 
> Looking at all the users of of *iio_triggered_buffer_setup*() the
> primary handler is either NULL or iio_pollfunc_store_time(). 
> So IRQF_ONESHOST should work all the time.
> 
> Then there is 
> - drivers/iio/adc/vf610_adc.c 
> - drivers/iio/common/hid-sensors/hid-sensor-trigger.c

I think we also have in the list:

- drivers/iio/adc/stm32-dfsdm-adc.c

> 
> They use iio_pollfunc_store_time() as primary and have no secondary.
> This would trigger the warning but not having a secondary handler while
> returning IRQF_WAKE_THREAD should create a warning of its own.
> What did I miss?
> 
>> Bert Karwatzki
> 
> Sebastian
>