From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A77A91C08 for ; Wed, 30 Aug 2023 11:20:16 +0000 (UTC) Received: from pandora.armlinux.org.uk (unknown [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6E3A91BB; Wed, 30 Aug 2023 04:20:15 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=04rA3QMGu6b8RzLVqZdwsj34mORbZ+1WIjhmdElzWKA=; b=M76T7FdSLwSJ2klAhj8Gg+yM/5 EMEc+J0aZdzFLyN41/fOmVUyfcToAPl5pVqbZOK/BRn7v57j8HB95Od9hEaYmGVYIKKcztQ1ItJZk KDLQl9S4mg9fSQpTpBryiD7VGliK+bzgiAlFQTZW8w+4gFyMFP7VS9j4UfbDsQk+CMScTqA7G1Tk8 dM1bg8tcvuoxqu0UTNMVZ2bk17KhBnmJkN+JsfLu3rXrE2/qb+fvD682C+hPZdLDDW3UttQiYTqTz 5a4tFAg1phPgDnYDxHARy8LVobVfNohj6XtpvLaRoKZbLbdVHTvQ1DyENNJSFSLTyNmSSLvSoc6Ur i35sZNeg==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:56328) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1qbJEx-0001Vs-1w; Wed, 30 Aug 2023 12:20:03 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1qbJEx-0005dp-E1; Wed, 30 Aug 2023 12:20:03 +0100 Date: Wed, 30 Aug 2023 12:20:03 +0100 From: "Russell King (Oracle)" To: Oleksij Rempel Cc: Lukasz Majewski , Eric Dumazet , Andrew Lunn , davem@davemloft.net, Woojung Huh , Vladimir Oltean , Tristram.Ha@microchip.com, Florian Fainelli , Jakub Kicinski , Paolo Abeni , UNGLinuxDriver@microchip.com, Heiner Kallweit , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] net: phy: Provide Module 4 KSZ9477 errata (DS80000754C) Message-ID: References: <20230830092119.458330-1-lukma@denx.de> <20230830092119.458330-2-lukma@denx.de> <20230830101813.GG31399@pengutronix.de> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230830101813.GG31399@pengutronix.de> Sender: Russell King (Oracle) X-Spam-Status: No, score=-1.3 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED,RDNS_NONE, SPF_HELO_NONE,SPF_NONE autolearn=no autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On Wed, Aug 30, 2023 at 12:18:13PM +0200, Oleksij Rempel wrote: > On Wed, Aug 30, 2023 at 11:21:19AM +0200, Lukasz Majewski wrote: > > The KSZ9477 errata points out (in 'Module 4') the link up/down problem > > 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. > > > > Signed-off-by: Lukasz Majewski > > --- > > drivers/net/phy/micrel.c | 31 ++++++++++++++++++++++++++++++- > > 1 file changed, 30 insertions(+), 1 deletion(-) > > > > diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c > > index 87b090ad2874..469dcd8a5711 100644 > > --- a/drivers/net/phy/micrel.c > > +++ b/drivers/net/phy/micrel.c > > @@ -1418,6 +1418,35 @@ static int ksz9131_get_features(struct phy_device *phydev) > > return 0; > > } > > > > +static int ksz9477_get_features(struct phy_device *phydev) > > +{ > > + __ETHTOOL_DECLARE_LINK_MODE_MASK(zero) = { 0, }; > > + int ret; > > + > > + ret = genphy_read_abilities(phydev); > > + if (ret) > > + return ret; > > + > > + /* KSZ9477 Errata DS80000754C > > + * > > + * Module 4: Energy Efficient Ethernet (EEE) feature select must be > > + * manually disabled > > + * The EEE feature is enabled by default, but it is not fully > > + * operational. It must be manually disabled through register > > + * controls. If not disabled, the PHY ports can auto-negotiate > > + * to enable EEE, and this feature can cause link drops when linked > > + * to another device supporting EEE. > > + * > > + * Although, the KSZ9477 MMD register > > + * (MMD_DEVICE_ID_EEE_ADV.MMD_EEE_ADV) advertise that EEE is > > + * operational one needs to manualy clear them to follow the chip > > + * errata. > > + */ > > + linkmode_and(phydev->supported_eee, phydev->supported, zero); > > + > > + return 0; > > +} > > + > > #define KSZ8873MLL_GLOBAL_CONTROL_4 0x06 > > #define KSZ8873MLL_GLOBAL_CONTROL_4_DUPLEX BIT(6) > > #define KSZ8873MLL_GLOBAL_CONTROL_4_SPEED BIT(4) > > @@ -4871,7 +4900,7 @@ static struct phy_driver ksphy_driver[] = { > > .handle_interrupt = kszphy_handle_interrupt, > > .suspend = genphy_suspend, > > .resume = genphy_resume, > > - .get_features = ksz9131_get_features, > > + .get_features = ksz9477_get_features, > > Sorry, i didn't described all details how to implement it. > > This code will break EEE support for the KSZ8563R switch. > > Please search for MICREL_KSZ8_P1_ERRATA in the kernel source. > Then add new flag, for example MICREL_NO_EEE and use it in a similar > way how MICREL_KSZ8_P1_ERRATA was set and used. With this > implementation, first patch is not needed. > > The code will be something like this: > if (dev_flags & MICREL_NO_EEE) > /* lots of comments */ > linkmode_and(phydev->supported_eee, phydev->supported, zero); I can't believe two people are writing code like this... linkmode_zero(phydev->supported_eee); will work just as well. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!