[PATCH 0/2] irq-meson-gpio: make it possible to build as a module

[Kevin Hilman]

Marc Zyngier <maz at kernel.org> writes:

> On 2020-10-26 16:18, Kevin Hilman wrote:
>> Marc Zyngier <maz at kernel.org> writes:
>> 
>>> On Tue, 20 Oct 2020 08:25:30 +0100,
>>> Neil Armstrong <narmstrong at 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.
>> 
>> Yes, but this series still keeps the default as built-in.
>> 
>> If you build as a module, and you add `fw_devlink=on` to the kernel
>> command-line, device-links will be created based on DT dependencies
>> which will ensure the right module load order.
>
> It doesn't work here. I get the exact same error (well, with eth0 
> instead
> of eth1). In my experience, fw_devlink isn't reliable yet. Config on 
> request.

Other than CONFIG_MESON_IRQ_GPIO=m, are you using default upstream
defconfig?

I just double-checked with this series on top of v5.10-rc1, and I have
eth0 working with interrupts without needing fw_devlink=on.

With the default upstream defconfig all the networking for these devices
is already configured as modules.

Kevin