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From:   Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Date:   Tue, 3 Nov 2020 06:53:17 +0100
Message-ID: <CAFBinCCZiO9Xe1WKT8MZ-90c7m1u_m1Mt-OXf=Pyuo0vukQQ5g@mail.gmail.com>
Subject: Re: [PATCH AUTOSEL 5.4 05/24] arm64: dts: amlogic: meson-g12: use the
 G12A specific dwmac compatible
To:     Sasha Levin <sashal@kernel.org>
Cc:     linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Neil Armstrong <narmstrong@baylibre.com>,
        Kevin Hilman <khilman@baylibre.com>,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-amlogic@lists.infradead.org
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Hi Sasha,

On Tue, Nov 3, 2020 at 2:20 AM Sasha Levin <sashal@kernel.org> wrote:
>
> From: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
>
> [ Upstream commit 1fdc97ae450ede2b4911d6737a57e6fca63b5f4a ]
>
> We have a dedicated "amlogic,meson-g12a-dwmac" compatible string for the
> Ethernet controller since commit 3efdb92426bf4 ("dt-bindings: net:
> dwmac-meson: Add a compatible string for G12A onwards").
> Using the AXG compatible string worked fine so far because the
> dwmac-meson8b driver doesn't handle the newly introduced register bits
> for G12A. However, once that changes the driver must be probed with the
> correct compatible string to manage these new register bits.
>
> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com>
> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com>
> Signed-off-by: Kevin Hilman <khilman@baylibre.com>
> Link: https://lore.kernel.org/r/20200925211743.537496-1-martin.blumenstingl@googlemail.com
> Signed-off-by: Sasha Levin <sashal@kernel.org>
if this patch will be included in 5.4-stable then please also backport
the following two commits:
- 3efdb92426bf4 ("dt-bindings: net: dwmac-meson: Add a compatible
string for G12A onwards")
- a4f63342d03d2d ("net: stmmac: dwmac-meson8b: add a compatible string
for G12A SoCs")

Without these above two commits we'll lose Ethernet connectivity
because there's no G12A compatible string in 5.4 yet

The quick solution would be to not backport this patch because the
driver in question doesn't do anything with the new compatible string
yet.


Best regards,
Martin