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 X-Spam-Level: X-Spam-Status: No, score=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4F948C83004 for ; Wed, 29 Apr 2020 19:52:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 397FC206D6 for ; Wed, 29 Apr 2020 19:52:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726858AbgD2Tw2 (ORCPT ); Wed, 29 Apr 2020 15:52:28 -0400 Received: from mx2.suse.de ([195.135.220.15]:60218 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726456AbgD2Tw1 (ORCPT ); Wed, 29 Apr 2020 15:52:27 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 979CEADFF; Wed, 29 Apr 2020 19:52:23 +0000 (UTC) Received: by lion.mk-sys.cz (Postfix, from userid 1000) id 56810604EB; Wed, 29 Apr 2020 21:52:22 +0200 (CEST) Date: Wed, 29 Apr 2020 21:52:22 +0200 From: Michal Kubecek To: Oleksij Rempel Cc: Andrew Lunn , "David S. Miller" , Florian Fainelli , Heiner Kallweit , Jakub Kicinski , Jonathan Corbet , David Jander , kernel@pengutronix.de, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Russell King , mkl@pengutronix.de, Marek Vasut , Christian Herber Subject: Re: [PATCH net-next v3 1/2] ethtool: provide UAPI for PHY master/slave configuration. Message-ID: <20200429195222.GA17581@lion.mk-sys.cz> References: <20200428075308.2938-1-o.rempel@pengutronix.de> <20200428075308.2938-2-o.rempel@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200428075308.2938-2-o.rempel@pengutronix.de> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, Apr 28, 2020 at 09:53:07AM +0200, Oleksij Rempel wrote: > This UAPI is needed for BroadR-Reach 100BASE-T1 devices. Due to lack of > auto-negotiation support, we needed to be able to configure the > MASTER-SLAVE role of the port manually or from an application in user > space. > > The same UAPI can be used for 1000BASE-T or MultiGBASE-T devices to > force MASTER or SLAVE role. See IEEE 802.3-2018: > 22.2.4.3.7 MASTER-SLAVE control register (Register 9) > 22.2.4.3.8 MASTER-SLAVE status register (Register 10) > 40.5.2 MASTER-SLAVE configuration resolution > 45.2.1.185.1 MASTER-SLAVE config value (1.2100.14) > 45.2.7.10 MultiGBASE-T AN control 1 register (Register 7.32) > > The MASTER-SLAVE role affects the clock configuration: > > ------------------------------------------------------------------------------- > When the PHY is configured as MASTER, the PMA Transmit function shall > source TX_TCLK from a local clock source. When configured as SLAVE, the > PMA Transmit function shall source TX_TCLK from the clock recovered from > data stream provided by MASTER. > > iMX6Q KSZ9031 XXX > ------\ /-----------\ /------------\ > | | | | | > MAC |<----RGMII----->| PHY Slave |<------>| PHY Master | > |<--- 125 MHz ---+-<------/ | | \ | > ------/ \-----------/ \------------/ > ^ > \-TX_TCLK > > ------------------------------------------------------------------------------- > > Since some clock or link related issues are only reproducible in a > specific MASTER-SLAVE-role, MAC and PHY configuration, it is beneficial > to provide generic (not 100BASE-T1 specific) interface to the user space > for configuration flexibility and trouble shooting. > > Signed-off-by: Oleksij Rempel > --- [...] > diff --git a/drivers/net/phy/phy.c b/drivers/net/phy/phy.c > index 72c69a9c8a98a..a6a774beb2f90 100644 > --- a/drivers/net/phy/phy.c > +++ b/drivers/net/phy/phy.c > @@ -285,6 +285,9 @@ int phy_ethtool_ksettings_set(struct phy_device *phydev, > duplex != DUPLEX_FULL))) > return -EINVAL; > > + if (!ethtool_validate_master_slave_cfg(cmd->base.master_slave_cfg)) > + return -EINVAL; > + Unless we can/want to pass extack down here, I would prefer to have the sanity check in ethtool_update_linkmodes() or ethtool_set_linkmodes() so that we can set meaningful error message and offending attribute in extack. (It could be even part of the policy.) Also, with the check only here, drivers/devices not calling phy_ethtool_set_link_ksettings() (directly or via phy_ethtool_set_link_ksettings()) and not handling the new members themselves would silently ignore any value from userspace. > phydev->autoneg = autoneg; > > phydev->speed = speed; [...] > +static int genphy_setup_master_slave(struct phy_device *phydev) > +{ > + u16 ctl = 0; > + > + if (!phydev->is_gigabit_capable) > + return 0; Shouldn't we rather return -EOPNOTSUPP if value different from CFG_UNKNOWN was requested? > + > + switch (phydev->master_slave_set) { > + case PORT_MODE_CFG_MASTER_PREFERRED: > + ctl |= CTL1000_PREFER_MASTER; > + break; > + case PORT_MODE_CFG_SLAVE_PREFERRED: > + break; > + case PORT_MODE_CFG_MASTER_FORCE: > + ctl |= CTL1000_AS_MASTER; > + /* fallthrough */ > + case PORT_MODE_CFG_SLAVE_FORCE: > + ctl |= CTL1000_ENABLE_MASTER; > + break; > + case PORT_MODE_CFG_UNKNOWN: > + return 0; > + default: > + phydev_warn(phydev, "Unsupported Master/Slave mode\n"); > + return 0; > + } [...] > diff --git a/include/uapi/linux/ethtool.h b/include/uapi/linux/ethtool.h > index 92f737f101178..eb680e3d6bda5 100644 > --- a/include/uapi/linux/ethtool.h > +++ b/include/uapi/linux/ethtool.h > @@ -1666,6 +1666,31 @@ static inline int ethtool_validate_duplex(__u8 duplex) > return 0; > } > > +/* Port mode */ > +#define PORT_MODE_CFG_UNKNOWN 0 > +#define PORT_MODE_CFG_MASTER_PREFERRED 1 > +#define PORT_MODE_CFG_SLAVE_PREFERRED 2 > +#define PORT_MODE_CFG_MASTER_FORCE 3 > +#define PORT_MODE_CFG_SLAVE_FORCE 4 > +#define PORT_MODE_STATE_UNKNOWN 0 > +#define PORT_MODE_STATE_MASTER 1 > +#define PORT_MODE_STATE_SLAVE 2 > +#define PORT_MODE_STATE_ERR 3 You have "MASTER_SLAVE" or "master_slave" everywhere but "PORT_MODE" in these constants which is inconsistent. > + > +static inline int ethtool_validate_master_slave_cfg(__u8 cfg) > +{ > + switch (cfg) { > + case PORT_MODE_CFG_MASTER_PREFERRED: > + case PORT_MODE_CFG_SLAVE_PREFERRED: > + case PORT_MODE_CFG_MASTER_FORCE: > + case PORT_MODE_CFG_SLAVE_FORCE: > + case PORT_MODE_CFG_UNKNOWN: > + return 1; > + } > + > + return 0; > +} Should we really allow CFG_UNKNOWN in client requests? As far as I can see, this value is handled as no-op which should be rather expressed by absence of the attribute. Allowing the client to request a value, keeping current one and returning 0 (success) is IMHO wrong. Also, should this function be in UAPI header? [...] > @@ -119,7 +123,12 @@ static int linkmodes_fill_reply(struct sk_buff *skb, > } > > if (nla_put_u32(skb, ETHTOOL_A_LINKMODES_SPEED, lsettings->speed) || > - nla_put_u8(skb, ETHTOOL_A_LINKMODES_DUPLEX, lsettings->duplex)) > + nla_put_u8(skb, ETHTOOL_A_LINKMODES_DUPLEX, lsettings->duplex) || > + nla_put_u8(skb, ETHTOOL_A_LINKMODES_MASTER_SLAVE_CFG, > + lsettings->master_slave_cfg) || > + nla_put_u8(skb, ETHTOOL_A_LINKMODES_MASTER_SLAVE_STATE, > + lsettings->master_slave_state)) > + > return -EMSGSIZE; >From the two handlers you introduced, it seems we only get CFG_UNKNOWN or STATE_UNKNOWN if driver or device does not support the feature at all so it would be IMHO more appropriate to omit the attribute in such case. Michal > > return 0;