Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::3:2 as permitted sender) client-ip=2620:137:e000::3:2;
MIME-Version: 1.0
References: <655e4939.5d0a0220.d9a9e.0491@mx.google.com> <6a030399-b8ed-4e2c-899f-d82eb437aafa@lunn.ch>
 <655f2ba9.5d0a0220.294f3.38d8@mx.google.com> <c697488a-d34c-4c98-b4c7-64aef2fe583f@lunn.ch>
 <ZV9jM7ve3Kl6ZxSl@shell.armlinux.org.uk> <e32d5c84-7a88-4d9f-868f-98514deae6e9@lunn.ch>
 <655fa905.df0a0220.49d9b.7afd@mx.google.com> <367c0aea-b110-4e3f-a161-59d27db11188@quicinc.com>
 <ZWCQv9oaACowJck0@shell.armlinux.org.uk> <4d159a99-f602-424e-a3c1-259c52e4d543@lunn.ch>
 <ZWC+PbNjir7rT4MK@shell.armlinux.org.uk>
In-Reply-To: <ZWC+PbNjir7rT4MK@shell.armlinux.org.uk>
From:   Robert Marko <robert.marko@sartura.hr>
Date:   Fri, 24 Nov 2023 17:59:15 +0100
Message-ID: <CA+HBbNHkAxnTLo2N_-LtMCPhZLsqPAjpYUKBNoRqKc1qmbg=GQ@mail.gmail.com>
Subject: Re: [net-next RFC PATCH 03/14] dt-bindings: net: document ethernet
 PHY package nodes
To:     "Russell King (Oracle)" <linux@armlinux.org.uk>
Cc:     Andrew Lunn <andrew@lunn.ch>, Jie Luo <quic_luoj@quicinc.com>,
        Christian Marangi <ansuelsmth@gmail.com>,
        Rob Herring <robh@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Conor Dooley <conor+dt@kernel.org>,
        Andy Gross <agross@kernel.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Florian Fainelli <florian.fainelli@broadcom.com>,
        Broadcom internal kernel review list 
        <bcm-kernel-feedback-list@broadcom.com>,
        Daniel Golle <daniel@makrotopia.org>,
        Qingfang Deng <dqfext@gmail.com>,
        SkyLake Huang <SkyLake.Huang@mediatek.com>,
        Matthias Brugger <matthias.bgg@gmail.com>,
        AngeloGioacchino Del Regno 
        <angelogioacchino.delregno@collabora.com>,
        David Epping <david.epping@missinglinkelectronics.com>,
        Vladimir Oltean <olteanv@gmail.com>,
        Harini Katakam <harini.katakam@amd.com>,
        Simon Horman <horms@kernel.org>, netdev@vger.kernel.org,
        devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
        linux-arm-msm@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
Precedence: bulk

On Fri, Nov 24, 2023 at 4:16=E2=80=AFPM Russell King (Oracle)
<linux@armlinux.org.uk> wrote:
>
> On Fri, Nov 24, 2023 at 03:44:20PM +0100, Andrew Lunn wrote:
> > >             First Serdes mode       Second Serdes mode
> > > Option 1    PSGMII for copper       Disabled
> > >             ports 0-4
> > > Option 2    PSGMII for copper       1000BASE-X / 100BASE-FX
> > >             ports 0-4
> > > Option 3    QSGMII for copper       SGMII for
> > >             ports 0-3               copper port 4
> >
> > With option 2, can the second SERDES also do SGMII? You are likely to
> > need that when a Copper SFP module is inserted into the cage.
>
> The document states "The fiber port supports 1000BASE-X/100BASE-FX".
>
> The same is true of Marvell 88x3310's fiber port - it supports only
> fiber not SGMII. This is actually something else that - when the
> patches for stacked PHYs mature - will need to be addressed. If we
> have a 1G copper SFP plugged into an interface that only supports
> 1000base-X then we need a way to switch the PHY on the SFP module
> to 1000base-X if it's in SGMII mode.
>
> Some copper SFPs come up in 1000base-X mode, and we currently rely
> on the 88e1111 driver to switch them to SGMII mode. Others do want
> SGMII mode (like Mikrotik RJ01 where the PHY is inaccessible and
> thus can't be reconfigured.)

I can confirm that SGMII mode doesn't work with Option 2, I have tested thi=
s
a while ago with Mikrotik RJ01 (I think it has AR803x, but its not accessib=
le as
you pointed out) and it was somewhat working but in half duplex only
and dropping
packets.
Currently, SFP mode is checked and only 1000Base-X and 100Base-FX are
accepted, otherwise the module insert will return and error for unsupported
mode.

Regards,
Robert

>
> --
> RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
> FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!


--=20
Robert Marko
Staff Embedded Linux Engineer
Sartura Ltd.
Lendavska ulica 16a
10000 Zagreb, Croatia
Email: robert.marko@sartura.hr
Web: www.sartura.hr