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Date:   Wed, 04 Aug 2021 09:50:08 +0100
Message-ID: <87sfzpwq4f.wl-maz@kernel.org>
From:   Marc Zyngier <maz@kernel.org>
To:     Saravana Kannan <saravanak@google.com>
Cc:     Kevin Hilman <khilman@baylibre.com>,
        Lee Jones <lee.jones@linaro.org>,
        Neil Armstrong <narmstrong@baylibre.com>,
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        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] irqchip: irq-meson-gpio: make it possible to build as a module
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On Wed, 04 Aug 2021 02:36:45 +0100,
Saravana Kannan <saravanak@google.com> wrote:

Hi Saravana,

Thanks for looking into this.

[...]

> > Saravana, could you please have a look from a fw_devlink perspective?
> 
> Sigh... I spent several hours looking at this and wrote up an analysis
> and then realized I might be looking at the wrong DT files.
> 
> Marc, can you point me to the board file in upstream that corresponds
> to the platform in which you see this issue? I'm not asking for [1],
> but the actual final .dts (not .dtsi) file that corresponds to the
> platform/board/system.

The platform I can reproduce this on is described in
arch/arm64/boot/dts/amlogic/meson-sm1-khadas-vim3l.dts. It is an
intricate maze of inclusion, node merge and other DT subtleties. I
suggest you look at the decompiled version to get a view of the
result.

> Based on your error messages, it's failing for mdio@0 which
> corresponds to ext_mdio. But none of the board dts files in upstream
> have a compatible property for "ext_mdio". Which means fw_devlink
> _should_ propagate the gpio_intc IRQ dependency all the way up to
> eth_phy.
> 
> Also, in the failing case, can you run:
> ls -ld supplier:*
> 
> in the /sys/devices/....<something>/ folder that corresponds to the
> "eth_phy: mdio-multiplexer@4c000" DT node and tell me what it shows?

Here you go:

root@tiger-roach:~# find /sys/devices/ -name 'supplier*'|grep -i mdio | xargs ls -ld
lrwxrwxrwx 1 root root 0 Aug  4 09:47 /sys/devices/platform/soc/ff600000.bus/ff64c000.mdio-multiplexer/supplier:platform:ff63c000.system-controller:clock-controller -> ../../../../virtual/devlink/platform:ff63c000.system-controller:clock-controller--platform:ff64c000.mdio-multiplexer
lrwxrwxrwx 1 root root 0 Aug  4 09:47 /sys/devices/virtual/devlink/platform:ff63c000.system-controller:clock-controller--platform:ff64c000.mdio-multiplexer/supplier -> ../../../platform/soc/ff600000.bus/ff63c000.bus/ff63c000.system-controller/ff63c000.system-controller:clock-controller

Thanks,

	M.

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