linux-kernel - Re: [PATCH 3/3] gpio: sch: Enable IRQ support for Quark X1000

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Message-ID: <CACRpkdaP_kRPLCyVATPN9LjnwNqBEf2-fDqHUqjxdS2aBt1Ljw@mail.gmail.com>
Date:	Wed, 15 Oct 2014 08:55:37 +0200
From:	Linus Walleij <linus.walleij@...aro.org>
To:	Mika Westerberg <mika.westerberg@...ux.intel.com>
Cc:	"Chang, Rebecca Swee Fun" <rebecca.swee.fun.chang@...el.com>,
	"linux-gpio@...r.kernel.org" <linux-gpio@...r.kernel.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 3/3] gpio: sch: Enable IRQ support for Quark X1000

On Fri, Sep 26, 2014 at 11:18 AM, Mika Westerberg
<mika.westerberg@...ux.intel.com> wrote:
> On Fri, Sep 26, 2014 at 09:14:48AM +0000, Chang, Rebecca Swee Fun wrote:

>> > > +
>> > > +         /* disable interrupts */
>> > > +         sch_gpio_irq_disable_all(sch, sch->chip.ngpio);
>> > > +
>> > > +         err = request_irq(sch->irq_num, sch_gpio_irq_handler,
>> > > +                           IRQF_SHARED, KBUILD_MODNAME, sch);
>> >
>> > This seems weird, typically irqchip drivers don't call request_irq() directly but
>> > instead irq_set_chained_handler() or similar. With
>> > gpiochip_irqchip_* stuff you don't need even that.
>> >
>> Regarding this, gpio-sch is actually using shared interrupts and the
>> IRQ resources are from ACPI SCI. As per my understanding, resources
>> from ACPI SCI might be shared for power management purposes. In this
>> case, irq_set_chained_handler() might not be able to use here. What do
>> you think?
>
> I think you are right. And then you can't use gpiochip_irqchip_* helpers
> either :-(

No since that implies that the gpiochip lives in its own irqdomain,
and this driver uses a linear range of irqs provided from another
domain, just allocates descriptors for them.

I'll take a look at this and see if it's merge material now.

Yours,
Linus Walleij
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