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Date:   Fri, 22 Apr 2022 14:58:49 +0200
From:   Andrew Lunn <andrew@lunn.ch>
To:     Ong Boon Leong <boon.leong.ong@intel.com>
Cc:     Alexandre Torgue <alexandre.torgue@st.com>,
        Jose Abreu <joabreu@synopsys.com>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Russell King <linux@armlinux.org.uk>,
        Paolo Abeni <pabeni@redhat.com>,
        "David S . Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre Torgue <alexandre.torgue@foss.st.com>,
        Giuseppe Cavallaro <peppe.cavallaro@st.com>,
        netdev@vger.kernel.org, linux-stm32@st-md-mailman.stormreply.com,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH net-next 2/4] net: stmmac: introduce PHY-less setup
 support
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References: <20220422073505.810084-1-boon.leong.ong@intel.com>
 <20220422073505.810084-3-boon.leong.ong@intel.com>
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On Fri, Apr 22, 2022 at 03:35:03PM +0800, Ong Boon Leong wrote:
> Certain platform uses PHY-less configuration whereby the MAC controller
> is connected to network switch chip directly over SGMII or 1000BASE-X.
> 
> This patch prepares the stmmac driver to support PHY-less configuration
> described above.

The normal way to do a PHY less setup is to use a fixed-PHY. It offers
the same API to the MAC as a real PHY but is fixed speed, dupex
etc. The MAC sees a PHY as usual, and you don't need anything special
in the MAC.

What you need to do is extend your DSD to list the fixed-link. See

https://www.kernel.org/doc/html/latest/firmware-guide/acpi/dsd/phy.html#mac-node-example-with-a-fixed-link-subnode

	Andrew