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Date:   Fri, 10 Jan 2020 14:58:49 +0000
From:   Russell King - ARM Linux admin <linux@armlinux.org.uk>
To:     Andre Przywara <andre.przywara@arm.com>
Cc:     "David S . Miller" <davem@davemloft.net>,
        Radhey Shyam Pandey <radhey.shyam.pandey@xilinx.com>,
        Robert Hancock <hancock@sedsystems.ca>, netdev@vger.kernel.org,
        Michal Simek <michal.simek@xilinx.com>,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 07/14] net: axienet: Fix SGMII support
Message-ID: <20200110145849.GC25745@shell.armlinux.org.uk>
References: <20200110115415.75683-1-andre.przywara@arm.com>
 <20200110115415.75683-8-andre.przywara@arm.com>
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On Fri, Jan 10, 2020 at 11:54:08AM +0000, Andre Przywara wrote:
> With SGMII, the MAC and the PHY can negotiate the link speed between
> themselves, without the host needing to mediate between them.
> Linux recognises this, and will call phylink's mac_config with the speed
> member set to SPEED_UNKNOWN (-1).

I wonder whether you have read the documentation for the phylink
mac_config() method (if not, please read it, it contains some very
important information about what mac_config() should do.)  When
operating in SGMII in-band mode, state->speed and state->duplex are
not actually valid.

You'll probably want to submit a better patch after reading the
documentation.

Thanks.

-- 
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