Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
MIME-Version: 1.0
References: <20200925033017.1790973-1-art@khadas.com> <20200925033017.1790973-6-art@khadas.com>
 <CAFBinCAJ6svwiv9OM6EHz7468D9h+jW_ULiGrorgLetcODsAKQ@mail.gmail.com> <CAKaHn9+CWLJYN1Tt46VxBGNBEbVVJZWeL6ZJSf9w-5DmoxrvgQ@mail.gmail.com>
In-Reply-To: <CAKaHn9+CWLJYN1Tt46VxBGNBEbVVJZWeL6ZJSf9w-5DmoxrvgQ@mail.gmail.com>
From:   Martin Blumenstingl <martin.blumenstingl@googlemail.com>
Date:   Fri, 25 Sep 2020 10:04:21 +0200
Message-ID: <CAFBinCD0_QgKKcH+Kb2QbMWnx_csoXMEhSFYzmDscdTVB2TUJw@mail.gmail.com>
Subject: Re: [PATCH 5/8] arm64: dts: meson: remove reset-gpios from ethernet
 node for VIM2 meson-gxm-khadas-vim2
To:     Art Nikpal <email2tema@gmail.com>
Cc:     Neil Armstrong <narmstrong@baylibre.com>, khilman@baylibre.com,
        robh+dt@kernel.org, jbrunet@baylibre.com,
        devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org,
        art@khadas.com, nick@khadas.com, gouwa@khadas.com
Content-Type: text/plain; charset="UTF-8"
Precedence: bulk

Hello Artem,

(adding back the mailing-list recipients)

On Fri, Sep 25, 2020 at 9:50 AM Art Nikpal <email2tema@gmail.com> wrote:
>
> hello
>
> > what is the problem that you observe here?
> > did you investigate further why resetting the PHY changes this?
>
> just try next commands
> ifconfig eth0 down && ifconfig eth0 up
> and ethernet never up again - need full reboot only
this means that "something" is either set up incorrectly in the Linux
kernel or that u-boot does some magic (and the same magic is then
missing in the Linux kernel)
I'll dig out my Khadas VIM2 to test this. what should I look out for
(are there any error messages, dhcp not getting an IP address anymore,
etc.)?

> but if reset-gpios will be remove it works fine already - i have checked it many times
>
> for example VIM3 same didnt use reset-gpios
that's interesting - I'm surprised to see this
I did a quick check and for 15 out of 18 .dts(i) files with RGMII
phy-mode we use the reset-gpios:
$ grep -R 'phy-mode = "rgmii' arch/arm64/boot/dts/amlogic/ | wc -l
18
$ grep -R 'ethernet-phy@0' -A10 arch/arm64/boot/dts/amlogic/ | grep
reset-gpios | wc -l
15

so really I would like to add the reset-gpios to the VIM3 .dtsi as
well once we figured out what's wrong on the VIM2


Best regards,
Martin