From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5706C83F01 for ; Wed, 30 Aug 2023 19:17:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S244275AbjH3TOT (ORCPT ); Wed, 30 Aug 2023 15:14:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53782 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243201AbjH3KSo (ORCPT ); Wed, 30 Aug 2023 06:18:44 -0400 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D82D81B7 for ; Wed, 30 Aug 2023 03:18:38 -0700 (PDT) Received: from ptx.hi.pengutronix.de ([2001:67c:670:100:1d::c0]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qbIH9-0000SY-5J; Wed, 30 Aug 2023 12:18:15 +0200 Received: from ore by ptx.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1qbIH7-0003o2-3S; Wed, 30 Aug 2023 12:18:13 +0200 Date: Wed, 30 Aug 2023 12:18:13 +0200 From: Oleksij Rempel To: Lukasz Majewski Cc: Eric Dumazet , Andrew Lunn , davem@davemloft.net, Woojung Huh , Vladimir Oltean , Tristram.Ha@microchip.com, Florian Fainelli , Jakub Kicinski , Paolo Abeni , UNGLinuxDriver@microchip.com, Russell King , 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: <20230830101813.GG31399@pengutronix.de> References: <20230830092119.458330-1-lukma@denx.de> <20230830092119.458330-2-lukma@denx.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230830092119.458330-2-lukma@denx.de> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-Accept-Language: de,en X-Accept-Content-Type: text/plain User-Agent: Mutt/1.10.1 (2018-07-13) X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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); else /* lots of other comments */ linkmode_and(phydev->supported_eee, phydev->supported, PHY_EEE_CAP1_FEATURES); On the switch driver side i would expect something like this: ksz_get_phy_flags(struct dsa_switch *ds, int port) swtich (dev->chip_id) case KSZ8830_CHIP_ID: .... break; case KSZ9477_CHIP_ID: return MICREL_NO_EEE; Regards, Oleksij -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |