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From:   Linus Walleij <linus.walleij@linaro.org>
Date:   Wed, 11 Nov 2020 15:09:19 +0100
Message-ID: <CACRpkdaTknFRSm4pcSf-v7Be8A_SnMMrhegu6W67gUjOJVLEBQ@mail.gmail.com>
Subject: Re: [PATCH v2 3/5] gpio: msc313: MStar MSC313 GPIO driver
To:     Marc Zyngier <maz@kernel.org>
Cc:     Daniel Palmer <daniel@0x0f.com>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>,
        "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
        <devicetree@vger.kernel.org>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
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On Tue, Nov 10, 2020 at 3:19 PM Marc Zyngier <maz@kernel.org> wrote:
> On 2020-11-10 14:02, Linus Walleij wrote:

> >> Probably nothing more than setting the callback to
> >> irq_chip_set_affinity_parent,
> >
> > Hm, is this something all GPIO irqchips used on SMP systems
> > should be doing? Or just hierarchical ones?
>
> Probably only the hierarchical ones. I'd expect the non-hierarchical
> GPIOs to be muxed behind a single interrupt, which makes it impossible
> to move a single GPIO around, and moving the mux interrupt would break
> userspace's expectations that interrupts move independently of each
> others.

I found two suspects and sent patches. I think I might have some
more candidates down in pinctrl. I do have some hierarchical IRQ
that is on UP systems, I suppose these are not affected.

Yours,
Linus Walleij