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From:   Rob Herring <robh@kernel.org>
Date:   Tue, 3 Aug 2021 09:47:42 -0600
Message-ID: <CAL_JsqJ6_ktTQKiy_xx9DhjQ3=imfvSZpBem5fXwVY7O49EgCw@mail.gmail.com>
Subject: Re: [PATCH V4 3/5] dt-bindings: gpio: Add bindings for gpio-virtio
To:     Viresh Kumar <viresh.kumar@linaro.org>
Cc:     Jason Wang <jasowang@redhat.com>,
        "Michael S. Tsirkin" <mst@redhat.com>,
        Arnd Bergmann <arnd@kernel.org>,
        Jean-Philippe Brucker <jean-philippe@linaro.org>,
        Linus Walleij <linus.walleij@linaro.org>,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Bill Mills <bill.mills@linaro.org>,
        =?UTF-8?B?QWxleCBCZW5uw6ll?= <alex.bennee@linaro.org>,
        "Enrico Weigelt, metux IT consult" <info@metux.net>,
        Jie Deng <jie.deng@intel.com>, devicetree@vger.kernel.org,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "open list:DRM DRIVER FOR QEMU'S CIRRUS DEVICE" 
        <virtualization@lists.linux-foundation.org>,
        Arnd Bergmann <arnd@arndb.de>,
        "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>
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n Mon, Aug 2, 2021 at 10:30 PM Viresh Kumar <viresh.kumar@linaro.org> wrote:
>
> On 02-08-21, 13:40, Rob Herring wrote:
> > Humm, how does one implement interrupts without a parent interrupt? It
> > uses the parent virtio,mmio interrupt?
>
> Kind of, yeah, but not necessarily.
>
> The interrupt information is passed over buffers shared between host and guest.
> Now the guest may process the buffers when it receives a notification from the
> host, that will be at downpath of an interrupt for virtio,mmio. Or the guest may
> poll on the virtqueue and process any buffers as soon as they are made
> available, no interrupts then.

Okay, thanks for the explanation.

Reviewed-by: Rob Herring <robh@kernel.org>

Rob