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Date:   Sun, 4 Dec 2022 18:23:49 +0100
From:   Andrew Lunn <andrew@lunn.ch>
To:     "Russell King (Oracle)" <linux@armlinux.org.uk>
Cc:     Piergiorgio Beruto <piergiorgio.beruto@gmail.com>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, linux-kernel@vger.kernel.org,
        netdev@vger.kernel.org, Oleksij Rempel <o.rempel@pengutronix.de>
Subject: Re: [PATCH net-next 3/4] drivers/net/phy: Add driver for the onsemi
 NCN26000 10BASE-T1S PHY
Message-ID: <Y4zXpWEo5rJdNecG@lunn.ch>
References: <cover.1670119328.git.piergiorgio.beruto@gmail.com>
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 <Y4zQNHEkWQG+C/Oj@shell.armlinux.org.uk>
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> > +
> > +	// bring up the link (link_ctrl is mapped to BMCR_ANENABLE)
> > +	// clear also ISOLATE mode and Collision Test
> > +	return phy_write(phydev, MII_BMCR, BMCR_ANENABLE);
> 
> You always use AN even when ethtool turns off AN? If AN is mandatory,
> it seems there should be some way that phylib can force that to be
> the case.

Hi Russell

The comment is trying to explain that the bit BMCR_ANENABLE does not
actually mean Enable Autoneg. Since AN is not supported by T1S PHYs,
and the standard, some vendors have repurposed this bit.

Maybe we need BMCR_T1S_LINK_CTRL, local to this driver.

      Andrew