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Date:   Tue, 5 Oct 2021 11:20:50 +0530
From:   Viresh Kumar <viresh.kumar@linaro.org>
To:     Geert Uytterhoeven <geert+renesas@glider.be>
Cc:     Linus Walleij <linus.walleij@linaro.org>,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>,
        Enrico@rox.of.borg, Weigelt@rox.of.borg,
        metux IT consult <lkml@metux.net>,
        Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
        Arnd Bergmann <arnd@kernel.org>, linux-gpio@vger.kernel.org,
        linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org,
        virtualization@lists.linux-foundation.org,
        stratos-dev@op-lists.linaro.org
Subject: Re: [PATCH] gpio: aggregator: Add interrupt support
Message-ID: <20211005055050.ggimidaqis5tfxav@vireshk-i7>
References: <c987d0bf744150ca05bd952f5f9e5fb3244d27b0.1633350340.git.geert+renesas@glider.be>
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On 04-10-21, 14:44, Geert Uytterhoeven wrote:
> Currently the GPIO Aggregator does not support interrupts.  This means
> that kernel drivers going from a GPIO to an IRQ using gpiod_to_irq(),
> and userspace applications using line events do not work.
> 
> Add interrupt support by providing a gpio_chip.to_irq() callback, which
> just calls into the parent GPIO controller.
> 
> Note that this does not implement full interrupt controller (irq_chip)
> support, so using e.g. gpio-keys with "interrupts" instead of "gpios"
> still does not work.

Hi Geert,

Thanks for looking into this. I am not sure of the difference it makes
with and without full irq-chip, but lemme explain the use case that we
are concerned about with virtio.

Eventually the interrupt should be visible to userspace, with
something like libgpiod. Which can then send the information over
virtio to the guest.

Will the interrupts be visible in userspace with your patch ?

-- 
viresh