linux-kernel - Re: [tip: irq/core] genirq: Warn about using IRQF

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Message-ID: <0a3433112f0bec3d5bd76c7ae9b6774b455203a6.camel@linux.intel.com>
Date: Tue, 03 Feb 2026 09:29:25 -0800
From: srinivas pandruvada <srinivas.pandruvada@...ux.intel.com>
To: Sebastian Andrzej Siewior <bigeasy@...utronix.de>, Bert Karwatzki
	 <spasswolf@....de>
Cc: linux-kernel@...r.kernel.org, linux-iio@...r.kernel.org, Jiri Kosina
	 <jikos@...nel.org>, Jonathan Cameron <jic23@...nel.org>, Thomas Gleixner
	 <tglx@...nel.org>, Laurent Pinchart <laurent.pinchart@...asonboard.com>
Subject: Re: [tip: irq/core] genirq: Warn about using IRQF_ONESHOT without a
 threaded handler

On Tue, 2026-02-03 at 09:38 +0100, 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
> 
> 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?
> 

hid-sensor doesn't need a bh handler. This patch can fix. 

diff --git a/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
b/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
index 5540e2d28f4a..b2b09b544f43 100644
--- a/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
+++ b/drivers/iio/common/hid-sensors/hid-sensor-trigger.c
@@ -227,6 +227,11 @@ static const struct iio_trigger_ops
hid_sensor_trigger_ops = {
        .set_trigger_state = &hid_sensor_data_rdy_trigger_set_state,
 };
 
+static irqreturn_t triggered_buffer_handler(int irq, void *p)
+{
+        return IRQ_HANDLED;
+}
+
 int hid_sensor_setup_trigger(struct iio_dev *indio_dev, const char
*name,
                                struct hid_sensor_common *attrb)
 {
@@ -240,7 +245,8 @@ int hid_sensor_setup_trigger(struct iio_dev
*indio_dev, const char *name,
                fifo_attrs = NULL;
 
        ret = iio_triggered_buffer_setup_ext(indio_dev,
-                                            &iio_pollfunc_store_time,
NULL,
+                                            &iio_pollfunc_store_time,
+                                            triggered_buffer_handler,
                                             IIO_BUFFER_DIRECTION_IN,
                                             NULL, fifo_attrs);
        if (ret) {


Or add it to industrialio-triggered-buffer.c as a common handler for
all caller with no bh, whatever Jonathan prefers.


Thanks,
Srinivas



> > Bert Karwatzki
> 
> Sebastian