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=-5.1 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 1A834C5519F for ; Sun, 29 Nov 2020 11:29:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CD87B2076A for ; Sun, 29 Nov 2020 11:29:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="szgfVuZ4" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726993AbgK2L3E (ORCPT ); Sun, 29 Nov 2020 06:29:04 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53326 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725867AbgK2L3D (ORCPT ); Sun, 29 Nov 2020 06:29:03 -0500 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0178BC0613CF; Sun, 29 Nov 2020 03:28:22 -0800 (PST) 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=sZ+dBX5S94khbymeif4mad8kZfApM2klPCUgh0A8MB8=; b=szgfVuZ4HYowNeC8qNNPA5p2B mQR2vQbHhbjHj+/z4iieIvsgiQ7senwiLVVfYeLQkoBqKTCDyRHSx69GCT6X0RxzHSTQO06aSxllc Ren5IbjAR1YdslTfakOdxkLWIYorv3uaCpZJdYMZLozPBeeHdkT6t0lu5VehcjeL/un9bV968nv6F 6TAe0JcN/u0MyG0I9iIacxmOzBkY/tDwfBvLaLVBZ0itDepp5W7meOltl8nzH5eNfQhRzifWIalIB lY7LViTw6WF8jOw6nu/Ob7rKyc1iXXgxLbyCzr/IDhY3tqhL0QL6R8xQztOKubxddziUBMK4/FItg NVD1SVJ5Q==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:37552) by pandora.armlinux.org.uk with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1kjKsJ-0005YA-Ff; Sun, 29 Nov 2020 11:28:15 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1kjKsI-0003xw-RX; Sun, 29 Nov 2020 11:28:14 +0000 Date: Sun, 29 Nov 2020 11:28:14 +0000 From: Russell King - ARM Linux admin To: Andrew Lunn Cc: Steen Hegelund , "David S. Miller" , Jakub Kicinski , Masahiro Yamada , Lars Povlsen , Bjarni Jonasson , Microchip Linux Driver Support , Alexandre Belloni , Microsemi List , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH 2/3] net: sparx5: Add Sparx5 switchdev driver Message-ID: <20201129112814.GH1605@shell.armlinux.org.uk> References: <20201127133307.2969817-1-steen.hegelund@microchip.com> <20201127133307.2969817-3-steen.hegelund@microchip.com> <20201128190616.GF2191767@lunn.ch> <20201128222828.GQ1551@shell.armlinux.org.uk> <20201129105245.GG1605@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201129105245.GG1605@shell.armlinux.org.uk> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: Russell King - ARM Linux admin Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Sun, Nov 29, 2020 at 10:52:45AM +0000, Russell King - ARM Linux admin wrote: > On Sat, Nov 28, 2020 at 10:28:28PM +0000, Russell King - ARM Linux admin wrote: > > On Sat, Nov 28, 2020 at 08:06:16PM +0100, Andrew Lunn wrote: > > > > +static void sparx5_phylink_mac_config(struct phylink_config *config, > > > > + unsigned int mode, > > > > + const struct phylink_link_state *state) > > > > +{ > > > > + struct sparx5_port *port = netdev_priv(to_net_dev(config->dev)); > > > > + struct sparx5_port_config conf; > > > > + int err = 0; > > > > + > > > > + conf = port->conf; > > > > + conf.autoneg = state->an_enabled; > > > > + conf.pause = state->pause; > > > > + conf.duplex = state->duplex; > > > > + conf.power_down = false; > > > > + conf.portmode = state->interface; > > > > + > > > > + if (state->speed == SPEED_UNKNOWN) { > > > > + /* When a SFP is plugged in we use capabilities to > > > > + * default to the highest supported speed > > > > + */ > > > > > > This looks suspicious. > > > > Yes, it looks highly suspicious. The fact that > > sparx5_phylink_mac_link_up() is empty, and sparx5_phylink_mac_config() > > does all the work suggests that this was developed before the phylink > > re-organisation, and this code hasn't been updated for it. > > > > Any new code for the kernel really ought to be updated for the new > > phylink methodology before it is accepted. > > > > Looking at sparx5_port_config(), it also seems to use > > PHY_INTERFACE_MODE_1000BASEX for both 1000BASE-X and 2500BASE-X. All > > very well for the driver to do that internally, but it's confusing > > when it comes to reviewing this stuff, especially when people outside > > of the driver (such as myself) reviewing it need to understand what's > > going on with the configuration. > > There are other issues too. > > Looking at sparx5_get_1000basex_status(), we have: > > + status->link = DEV2G5_PCS1G_LINK_STATUS_LINK_STATUS_GET(value) | > + DEV2G5_PCS1G_LINK_STATUS_SYNC_STATUS_GET(value); > > Why is the link status the logical OR of these? > > + if ((lp_abil >> 8) & 1) /* symmetric pause */ > + status->pause = MLO_PAUSE_RX | MLO_PAUSE_TX; > + if (lp_abil & (1 << 7)) /* asymmetric pause */ > + status->pause |= MLO_PAUSE_RX; > > is actually wrong, and I see I need to improve the documentation for > mac_pcs_get_state(). The intention in the documentation was concerning > hardware that indicated the _resolved_ status of pause modes. It was > not intended that drivers resolve the pause modes themselves. > > Even so, the above is still wrong; it takes no account of what is being > advertised at the local end. If one looks at the implementation in > phylink_decode_c37_word(), one will notice there is code to deal with > this. > > I think we ought to make phylink_decode_c37_word() and > phylink_decode_sgmii_word() public functions, and then this driver can > use these helpers to decode the link partner advertisement to the > phylink state. > > Does the driver need to provide an ethtool .get_link function? That > seems to bypass phylink. Why can't ethtool_op_get_link() be used? > > I think if ethtool_op_get_link() is used, we then have just one caller > for sparx5_get_port_status(), which means "struct sparx5_port_status" > can be eliminated and the code cleaned up to use the phylink decoding > helpers. (Sorry, I keep spotting bits in the code - it's really not an easy chunk of code to review.) I'm also not sure that this is really correct: + status->serdes_link = !phy_validate(port->serdes, PHY_MODE_ETHERNET, + port->conf.portmode, NULL); The documentation for phy_validate() says: * Used to check that the current set of parameters can be handled by * the phy. Implementations are free to tune the parameters passed as * arguments if needed by some implementation detail or * constraints. It will not change any actual configuration of the * PHY, so calling it as many times as deemed fit will have no side * effect. and clearly, passing NULL for opts, gives the function no opportunity to do what it's intended, so phy_validate() is being used for some other purpose than that which the drivers/phy subsystem intends it to be used for. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!