From: Nicolas Saenz Julienne <nsaenzju@redhat.com>
To: jic23@kernel.org, lars@metafoo.de, linux-iio@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, nsaenzju@redhat.com,
matt.ranostay@konsulko.com, andy.shevchenko@gmail.com
Subject: [PATCH] iio: chemical: atlas-sensor: Avoid using irq_work
Date: Thu, 24 Jun 2021 12:00:46 +0200 [thread overview]
Message-ID: <20210624100046.1037159-1-nsaenzju@redhat.com> (raw)
The atlas sensor driver currently registers a threaded IRQ handler whose
sole responsibility is to trigger an irq_work which will in turn run
iio_trigger_poll() in IRQ context.
This seems overkill given the fact that there already was a opportunity
to run iio_trigger_poll() in IRQ context in the top half of the IRQ
handler. So make use of it, ultimately avoiding a context switch, an
IPI, and reducing latency.
Signed-off-by: Nicolas Saenz Julienne <nsaenzju@redhat.com>
---
NOTE: This was only compile tested. I don't know much about iio_triggers
(or iio for that matter), but while reviewing irq_work usage this showed
up and seemed trivial enough to fix right away. There might be a subtle
reason why this is setup as such, but it would at least warrant a
comment.
drivers/iio/chemical/atlas-sensor.c | 15 ++-------------
1 file changed, 2 insertions(+), 13 deletions(-)
diff --git a/drivers/iio/chemical/atlas-sensor.c b/drivers/iio/chemical/atlas-sensor.c
index 9cb99585b6ff..710daa169d57 100644
--- a/drivers/iio/chemical/atlas-sensor.c
+++ b/drivers/iio/chemical/atlas-sensor.c
@@ -13,7 +13,6 @@
#include <linux/mutex.h>
#include <linux/err.h>
#include <linux/irq.h>
-#include <linux/irq_work.h>
#include <linux/i2c.h>
#include <linux/mod_devicetable.h>
#include <linux/regmap.h>
@@ -89,7 +88,6 @@ struct atlas_data {
struct iio_trigger *trig;
struct atlas_device *chip;
struct regmap *regmap;
- struct irq_work work;
unsigned int interrupt_enabled;
/* 96-bit data + 32-bit pad + 64-bit timestamp */
__be32 buffer[6] __aligned(8);
@@ -442,13 +440,6 @@ static const struct iio_buffer_setup_ops atlas_buffer_setup_ops = {
.predisable = atlas_buffer_predisable,
};
-static void atlas_work_handler(struct irq_work *work)
-{
- struct atlas_data *data = container_of(work, struct atlas_data, work);
-
- iio_trigger_poll(data->trig);
-}
-
static irqreturn_t atlas_trigger_handler(int irq, void *private)
{
struct iio_poll_func *pf = private;
@@ -474,7 +465,7 @@ static irqreturn_t atlas_interrupt_handler(int irq, void *private)
struct iio_dev *indio_dev = private;
struct atlas_data *data = iio_priv(indio_dev);
- irq_work_queue(&data->work);
+ iio_trigger_poll(data->trig);
return IRQ_HANDLED;
}
@@ -677,12 +668,10 @@ static int atlas_probe(struct i2c_client *client,
goto unregister_trigger;
}
- init_irq_work(&data->work, atlas_work_handler);
-
if (client->irq > 0) {
/* interrupt pin toggles on new conversion */
ret = devm_request_threaded_irq(&client->dev, client->irq,
- NULL, atlas_interrupt_handler,
+ atlas_interrupt_handler, NULL,
IRQF_TRIGGER_RISING |
IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
"atlas_irq",
--
2.31.1
next reply other threads:[~2021-06-24 10:01 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-24 10:00 Nicolas Saenz Julienne [this message]
2021-06-24 10:39 ` [PATCH] iio: chemical: atlas-sensor: Avoid using irq_work Andy Shevchenko
2021-06-24 11:13 ` Nicolas Saenz Julienne
2021-09-26 15:33 ` Jonathan Cameron
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