From: Andy Shevchenko <andy.shevchenko@gmail.com>
To: Nicolas Saenz Julienne <nsaenzju@redhat.com>
Cc: Jonathan Cameron <jic23@kernel.org>,
Lars-Peter Clausen <lars@metafoo.de>,
linux-iio <linux-iio@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Matt Ranostay <matt.ranostay@konsulko.com>
Subject: Re: [PATCH] iio: chemical: atlas-sensor: Avoid using irq_work
Date: Thu, 24 Jun 2021 13:39:23 +0300 [thread overview]
Message-ID: <CAHp75VcG-0L+qG5JirWH21bnpVwRv_wfjM6Sfd2pJrq4-OqJ0Q@mail.gmail.com> (raw)
In-Reply-To: <20210624100046.1037159-1-nsaenzju@redhat.com>
On Thu, Jun 24, 2021 at 1:01 PM Nicolas Saenz Julienne
<nsaenzju@redhat.com> wrote:
>
> 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
an 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.
...
> @@ -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);
Have you considered dropping atlas_interrupt_trigger_ops() altogether?
> return IRQ_HANDLED;
...
> 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,
So, you move it from threaded IRQ to be a hard IRQ handler (we have a
separate call for this).
Can you guarantee that handling of those events will be fast enough?
> IRQF_TRIGGER_RISING |
> IRQF_TRIGGER_FALLING | IRQF_ONESHOT,
> "atlas_irq",
--
With Best Regards,
Andy Shevchenko
next prev parent reply other threads:[~2021-06-24 10:40 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-24 10:00 [PATCH] iio: chemical: atlas-sensor: Avoid using irq_work Nicolas Saenz Julienne
2021-06-24 10:39 ` Andy Shevchenko [this message]
2021-06-24 11:13 ` Nicolas Saenz Julienne
2021-09-26 15:33 ` Jonathan Cameron
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