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 8F0BFCD6E77 for ; Wed, 11 Oct 2023 14:25:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1346871AbjJKOZz (ORCPT ); Wed, 11 Oct 2023 10:25:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60136 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235016AbjJKOZv (ORCPT ); Wed, 11 Oct 2023 10:25:51 -0400 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [IPv6:2a0a:edc0:2:b01:1d::104]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DCF61B0 for ; Wed, 11 Oct 2023 07:25:49 -0700 (PDT) Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qqa9P-0007Ck-PJ; Wed, 11 Oct 2023 16:25:27 +0200 Received: from [2a0a:edc0:2:b01:1d::c0] (helo=ptx.whiteo.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1qqa9O-000vWv-7M; Wed, 11 Oct 2023 16:25:26 +0200 Received: from ore by ptx.whiteo.stw.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1qqa9O-00DwOh-4T; Wed, 11 Oct 2023 16:25:26 +0200 Date: Wed, 11 Oct 2023 16:25:26 +0200 From: Oleksij Rempel To: Alexander Stein Cc: Woojung Huh , UNGLinuxDriver@microchip.com, Andrew Lunn , Florian Fainelli , Vladimir Oltean , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Heiner Kallweit , netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@pengutronix.de, Russell King Subject: Re: [PATCH net-next v1 3/3] net: phy: micrel: Fix forced link mode for KSZ886X switches Message-ID: <20231011142526.GA3306548@pengutronix.de> References: <20231011123856.1443308-1-o.rempel@pengutronix.de> <20231011123856.1443308-3-o.rempel@pengutronix.de> <3767760.kQq0lBPeGt@steina-w> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <3767760.kQq0lBPeGt@steina-w> 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: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.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 Hi Alexander, thank you for review! On Wed, Oct 11, 2023 at 03:29:49PM +0200, Alexander Stein wrote: > Hi Oleksij, > > Am Mittwoch, 11. Oktober 2023, 14:38:56 CEST schrieb Oleksij Rempel: > > Address a link speed detection issue in KSZ886X PHY driver when in > > forced link mode. Previously, link partners like "ASIX AX88772B" > > with KSZ8873 could fall back to 10Mbit instead of configured 100Mbit. > > > > The issue arises as KSZ886X PHY continues sending Fast Link Pulses (FLPs) > > even with autonegotiation off, misleading link partners in autoneg mode, > > leading to incorrect link speed detection. > > > > Now, when autonegotiation is disabled, the driver sets the link state > > forcefully using KSZ886X_CTRL_FORCE_LINK bit. This action, beyond just > > disabling autonegotiation, makes the PHY state more reliably detected by > > link partners using parallel detection, thus fixing the link speed > > misconfiguration. > > > > With autonegotiation enabled, link state is not forced, allowing proper > > autonegotiation process participation. > > > > Signed-off-by: Oleksij Rempel > > --- > > drivers/net/phy/micrel.c | 32 +++++++++++++++++++++++++++++--- > > 1 file changed, 29 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/net/phy/micrel.c b/drivers/net/phy/micrel.c > > index 927d3d54658e..12f093aed4ff 100644 > > --- a/drivers/net/phy/micrel.c > > +++ b/drivers/net/phy/micrel.c > > @@ -1729,9 +1729,35 @@ static int ksz886x_config_aneg(struct phy_device > > *phydev) { > > int ret; > > > > - ret = genphy_config_aneg(phydev); > > - if (ret) > > - return ret; > > + if (phydev->autoneg != AUTONEG_ENABLE) { > > + ret = genphy_setup_forced(phydev); > > + if (ret) > > + return ret; > > + > > + /* When autonegotation is disabled, we need to manually > force > > + * the link state. If we don't do this, the PHY will keep > > + * sending Fast Link Pulses (FLPs) which are part of the > > + * autonegotiation process. This is not desired when > > + * autonegotiation is off. > > + */ > > + ret = phy_set_bits(phydev, MII_KSZPHY_CTRL, > > + KSZ886X_CTRL_FORCE_LINK); > > + if (ret) > > + return ret; > > + } else { > > + /* Make sure, the link state is not forced. > > + * Otherwise, the PHY we create a link by skipping the > > PHY will create? > > > + * autonegotiation process. > > + */ > > + ret = phy_clear_bits(phydev, MII_KSZPHY_CTRL, > > + KSZ886X_CTRL_FORCE_LINK); > > + if (ret) > > + return ret; > > Isn't this call to phy_clear_bits() a fix for autonegotiation mode? This > should be a separate patch then. First time this bit is set by this patch, I assume this problem would not exist without fixed link fix. 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 |