linux-kernel - Re: [PATCH 2/2] gpio: mockup: use irq_sim_fire

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Date:   Tue, 11 Dec 2018 16:38:54 +0100
From:   Bartosz Golaszewski <brgl@...ev.pl>
To:     Uwe Kleine-König 
        <u.kleine-koenig@...gutronix.de>
Cc:     Thomas Gleixner <tglx@...utronix.de>,
        Linus Walleij <linus.walleij@...aro.org>,
        Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@...r.kernel.org>,
        Bartosz Golaszewski <bgolaszewski@...libre.com>
Subject: Re: [PATCH 2/2] gpio: mockup: use irq_sim_fire_edge()

wt., 11 gru 2018 o 15:15 Uwe Kleine-König
<u.kleine-koenig@...gutronix.de> napisał(a):
>
> Hello Bartosz,
>
> On Mon, Dec 03, 2018 at 12:09:16PM +0100, Uwe Kleine-König wrote:
> > On Tue, Nov 20, 2018 at 02:40:32PM +0100, Bartosz Golaszewski wrote:
> > > @@ -213,7 +213,8 @@ static ssize_t gpio_mockup_event_write(struct file *file,
> > >     chip = priv->chip;
> > >
> > >     gpiod_set_value_cansleep(desc, val);
> > > -   irq_sim_fire(&chip->irqsim, priv->offset);
> > > +   edge = val == 0 ? IRQ_TYPE_EDGE_FALLING : IRQ_TYPE_EDGE_RISING;
> > > +   irq_sim_fire_edge(&chip->irqsim, priv->offset, edge);
> >
> > If I write 0 twice into the debugfs file, does it fire two irqs or only
> > one? I think it fires two but only one would be the right behaviour?!
>
> If you still think that patch 1 of this series is the way to go, I think
> this objection is still valid. Then you need to check the state of the
> line by at least calling (something like) .get_value to determine if the
> previous value was different.
>

Hi Uwe,

I've already started working on a series improving the entire concept.
I've taken some of your suggestions into account.

Since we're already at rc-6 I'd like to get those upstream despite
there being some disagreements to keep the userspace intact.

For now it will generate two falling edge interrupts when you write 0 twice.

Bart