Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
Date:   Mon, 27 Jan 2020 14:08:34 +0000
From:   Russell King - ARM Linux admin <linux@armlinux.org.uk>
To:     Andrew Lunn <andrew@lunn.ch>
Cc:     Jose Abreu <Jose.Abreu@synopsys.com>,
        "netdev@vger.kernel.org" <netdev@vger.kernel.org>,
        Joao Pinto <Joao.Pinto@synopsys.com>,
        Giuseppe Cavallaro <peppe.cavallaro@st.com>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        "David S. Miller" <davem@davemloft.net>,
        Jakub Kicinski <kuba@kernel.org>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        "linux-stm32@st-md-mailman.stormreply.com" 
        <linux-stm32@st-md-mailman.stormreply.com>,
        "linux-arm-kernel@lists.infradead.org" 
        <linux-arm-kernel@lists.infradead.org>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [RFC net-next 6/8] net: phylink: Configure MAC/PCS when link is
 up without PHY
Message-ID: <20200127140834.GW25745@shell.armlinux.org.uk>
References: <cover.1580122909.git.Jose.Abreu@synopsys.com>
 <9a2136885d9a892ff170be88fdffeda82c778a10.1580122909.git.Jose.Abreu@synopsys.com>
 <20200127112102.GT25745@shell.armlinux.org.uk>
 <BN8PR12MB3266714AE9EC1A97218120B3D30B0@BN8PR12MB3266.namprd12.prod.outlook.com>
 <20200127114600.GU25745@shell.armlinux.org.uk>
 <20200127140038.GD13647@lunn.ch>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20200127140038.GD13647@lunn.ch>
User-Agent: Mutt/1.10.1 (2018-07-13)
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

On Mon, Jan 27, 2020 at 03:00:38PM +0100, Andrew Lunn wrote:
> > Yes, I realise that, but it comes with the expense of potentially
> > breaking mvneta and mvpp2, where the settings are automatically
> > passed between the PCS and MAC in hardware. I also believe DSA
> > works around this, and I need to look at that.
> 
> Hi Russell
> 
> The mv88e6xxx driver has code for when SGMII is used. It transfers the
> negotiated speed from the PCS to the MAC.
> 
> But it recently turned out something like this is also needed for
> other link modes involving the SERDES. It used to work, i think
> because Phylink would initially configure the MAC approximately right,
> or the mv88e6xxx driver was looking at phylink state it should not.
> But it no longer works.

Can you give a hint which platform this is and how to reproduce it
please?

-- 
RMK's Patch system: https://www.armlinux.org.uk/developer/patches/
FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up
According to speedtest.net: 11.9Mbps down 500kbps up