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Date:   Sun, 25 Oct 2020 11:51:27 +0000
Message-ID: <87v9eyo75s.wl-maz@kernel.org>
From:   Marc Zyngier <maz@kernel.org>
To:     Neil Armstrong <narmstrong@baylibre.com>
Cc:     jbrunet@baylibre.com, linux-amlogic@lists.infradead.org,
        khilman@baylibre.com, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org
Subject: Re: [PATCH 0/2] irq-meson-gpio: make it possible to build as a module
In-Reply-To: <20201020072532.949137-1-narmstrong@baylibre.com>
References: <20201020072532.949137-1-narmstrong@baylibre.com>
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On Tue, 20 Oct 2020 08:25:30 +0100,
Neil Armstrong <narmstrong@baylibre.com> wrote:
> 
> In order to reduce the kernel Image size on multi-platform distributions,
> make it possible to build the Amlogic GPIO IRQ controller as a module
> by switching it to a platform driver.
> 
> The second patch removes MESON_IRQ_GPIO selection from ARCH_MESON to allow
> building the driver as module.
> 
> Neil Armstrong (2):
>   irqchip: irq-meson-gpio: make it possible to build as a module
>   arm64: meson: remove MESON_IRQ_GPIO selection
> 
>  arch/arm64/Kconfig.platforms     |  1 -
>  drivers/irqchip/Kconfig          |  5 +-
>  drivers/irqchip/irq-meson-gpio.c | 89 ++++++++++++++++++++------------
>  3 files changed, 59 insertions(+), 36 deletions(-)

I've tried this series on my vim3l with the this driver compiled as a
module, and lost the Ethernet interface in the process, as the phy
wasn't able to resolve its interrupt and things fail later on:

[   72.238291] meson8b-dwmac ff3f0000.ethernet eth1: no phy at addr -1
[   72.238917] meson8b-dwmac ff3f0000.ethernet eth1: stmmac_open: Cannot attach to PHY (error: -19)

This is a generic problem with making DT-based interrupt controllers
modular when not *all* the drivers can deal with probing deferral.

	M.

-- 
Without deviation from the norm, progress is not possible.