Re: [PATCH 18/21] iio: Replace IRQF_ONESHOT with IRQF_NO_THREAD

Andy Shevchenko
2026-01-23T14:49:02Z

On Fri, Jan 23, 2026 at 12:37:04PM +0100, Sebastian Andrzej Siewior wrote:
> Passing IRQF_ONESHOT ensures that the interrupt source is masked until
> the secondary (threaded) handler is done. If only a primary handler is
> used then the flag makes no sense because the interrupt can not fire
> (again) while its handler is running.
> The flag also disallows force-threading of the primary handler and the
> irq-core will warn about this.
>
> The intention here was probably not allowing forced-threading for
> handlers such as iio_trigger_generic_data_rdy_poll() will intends to
> invoke hard-interrupt handlers.
>
> Replace IRQF_ONESHOT with IRQF_NO_THREAD.

Code wise LGTM,
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>

There is a few nit-picks regarding style below.

...

> Cc: Lars-Peter Clausen <lars@metafoo.de>
> Cc: Michael Hennerich <Michael.Hennerich@analog.com>
> Cc: Puranjay Mohan <puranjay@kernel.org>
> Cc: Jonathan Cameron <jic23@kernel.org>
> Cc: David Lechner <dlechner@baylibre.com>
> Cc: "Nuno Sá" <nuno.sa@analog.com>
> Cc: Andy Shevchenko <andy@kernel.org>
> Cc: Marcelo Schmitt <marcelo.schmitt@analog.com>
> Cc: Marcus Folkesson <marcus.folkesson@gmail.com>
> Cc: Kent Gustavsson <kent@minoris.se>
> Cc: Gustavo Silva <gustavograzs@gmail.com>
> Cc: Nishant Malpani <nish.malpani25@gmail.com>
> Cc: linux-iio@vger.kernel.org

Move these...

> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
> ---

...to be here. This will drastically reduce the unneeded noise in the commit
message. The email will have (if using git format-patch and git send-email)
them.

...

> --- a/drivers/iio/accel/adxl355_core.c
> +++ b/drivers/iio/accel/adxl355_core.c
> @@ -770,7 +770,8 @@ static int adxl355_probe_trigger(struct iio_dev *indio_dev, int irq)
>
> ret = devm_request_irq(data->dev, irq,
> &iio_trigger_generic_data_rdy_poll,
> - IRQF_ONESHOT, "adxl355_irq", data->dready_trig);
> + IRQF_NO_THREAD,
> + "adxl355_irq", data->dready_trig);

Leave it on a single line. It's only 81 characters and it's fine to be like
this.

> if (ret)
> return dev_err_probe(data->dev, ret, "request irq %d failed\n",
> irq);

...

> +++ b/drivers/iio/accel/adxl372.c

> + ret = devm_request_irq(dev, st->irq,
> + iio_trigger_generic_data_rdy_poll,
> + IRQF_TRIGGER_RISING | IRQF_NO_THREAD,
> + indio_dev->name, st->dready_trig);
> if (ret < 0)
> return ret;

Interestingly that this driver ignores the flags from firmware... Seems to me
like a bug (not in your patch, obviously). Ditto for other drivers doing similar
things.

...

> --- a/drivers/iio/pressure/dlhl60d.c
> +++ b/drivers/iio/pressure/dlhl60d.c
> @@ -306,9 +306,9 @@ static int dlh_probe(struct i2c_client *client)
> indio_dev->num_channels = ARRAY_SIZE(dlh_channels);
>
> if (client->irq > 0) {
> - ret = devm_request_threaded_irq(&client->dev, client->irq,
> - dlh_interrupt, NULL,
> - IRQF_TRIGGER_RISING | IRQF_ONESHOT,
> + ret = devm_request_irq(&client->dev, client->irq,
> + dlh_interrupt,

Joined to the previous line it gives exactly 80 characters, which is allowed.

> + IRQF_TRIGGER_RISING | IRQF_NO_THREAD,
> st->info->name, indio_dev);

Forgot to indent.

...

> + ret = devm_request_irq(&client->dev, client->irq,
> + iio_trigger_generic_data_rdy_poll,
> + IRQF_NO_THREAD, "tmp006_irq",
> + data->drdy_trig);
> if (ret < 0)
> return ret;

Jonathan et al., this seems to me like a duplication from one to another
driver. Can't we do like a helper for it, so we don't change it each time
the IRQ core or other things got changed?

--
With Best Regards,
Andy Shevchenko