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Date:   Thu, 31 Aug 2023 09:51:37 +0200
From:   Oleksij Rempel <o.rempel@pengutronix.de>
To:     Lukasz Majewski <lukma@denx.de>
Cc:     Tristram.Ha@microchip.com, Eric Dumazet <edumazet@google.com>,
        Andrew Lunn <andrew@lunn.ch>, davem@davemloft.net,
        Woojung Huh <woojung.huh@microchip.com>,
        Vladimir Oltean <olteanv@gmail.com>,
        Florian Fainelli <f.fainelli@gmail.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>, UNGLinuxDriver@microchip.com,
        Russell King <linux@armlinux.org.uk>,
        Heiner Kallweit <hkallweit1@gmail.com>,
        Michael Walle <michael@walle.cc>,
        Horatiu Vultur <horatiu.vultur@microchip.com>,
        Arun Ramadoss <arun.ramadoss@microchip.com>,
        Oleksij Rempel <linux@rempel-privat.de>,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v3] net: phy: Provide Module 4 KSZ9477 errata
 (DS80000754C)
Message-ID: <20230831075137.GB17603@pengutronix.de>
References: <20230831072527.537839-1-lukma@denx.de>
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On Thu, Aug 31, 2023 at 09:25:27AM +0200, Lukasz Majewski wrote:
> The KSZ9477 errata points out (in 'Module 4') the link up/down problems
> when EEE (Energy Efficient Ethernet) is enabled in the device to which
> the KSZ9477 tries to auto negotiate.
> 
> The suggested workaround is to clear advertisement of EEE for PHYs in
> this chip driver.
> 
> To avoid regressions with other switch ICs the new MICREL_NO_EEE flag
> has been introduced.
> 
> Moreover, the in-register disablement of MMD_DEVICE_ID_EEE_ADV.MMD_EEE_ADV
> MMD register is removed, as this code is both; now executed too late
> (after previous rework of the PHY and DSA for KSZ switches) and not
> required as setting all members of eee_broken_modes bit field prevents
> the KSZ9477 from advertising EEE.
> 
> Fixes: 69d3b36ca045 ("net: dsa: microchip: enable EEE support") (for KSZ9477).
> 
> Signed-off-by: Lukasz Majewski <lukma@denx.de>
 
Tested-by: Oleksij Rempel <o.rempel@pengutronix.de>

Confirmed disabled EEE with oscilloscope.

Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>

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