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 BB93AC433DB for ; Thu, 14 Jan 2021 16:08:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7711523B28 for ; Thu, 14 Jan 2021 16:08:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728800AbhANQIF (ORCPT ); Thu, 14 Jan 2021 11:08:05 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:58000 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726293AbhANQIF (ORCPT ); Thu, 14 Jan 2021 11:08:05 -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 63880C061574 for ; Thu, 14 Jan 2021 08:07:22 -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-Transfer-Encoding:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Reply-To: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=SMrs3P+5EdO//YJvMfhcjIDwq4DzTSXhEXZyMIdqlAE=; b=JyZGY/ezUMaFrYiYRfYwR4tH+ 3AzxbpsbM91dNbQTbxD+l80242NNGmYwWlvEug7/cavbo1Zt8rfcTb65mzlq0aAr83Fnsg+RX7CzQ uLIRjwaUvqtBVAtaKp1XYugcLQ+NGsmxkDGY0P3Ng0gaWSoomWyyOjbyN/U33XP1cO26TmZ9awj6S RIfRC20XQjdUAKUcGTw5fS51US+wNaweZ8heXiMorPMuyiJXH6mpDjoXrhJQ3HOAe5eA/XJ5DnRsP 9fqLzN3bG34V91PI9Ffq5AVSJK4dJQk7wltSLlMk8wGAkBti1ylHjjGdYkJXobO3k62Ue8MapuXge DYQY9oWCA==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:47938) by pandora.armlinux.org.uk with esmtpsa (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1l059c-0002eB-Gj; Thu, 14 Jan 2021 16:07:20 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1l059b-0008TQ-G2; Thu, 14 Jan 2021 16:07:19 +0000 Date: Thu, 14 Jan 2021 16:07:19 +0000 From: Russell King - ARM Linux admin To: Marek =?iso-8859-1?Q?Beh=FAn?= Cc: netdev@vger.kernel.org, Andrew Lunn , Jakub Kicinski , davem@davemloft.net, pali@kernel.org Subject: Re: [PATCH net-next v5 4/5] net: sfp: create/destroy I2C mdiobus before PHY probe/after PHY release Message-ID: <20210114160719.GV1551@shell.armlinux.org.uk> References: <20210114044331.5073-1-kabel@kernel.org> <20210114044331.5073-5-kabel@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210114044331.5073-5-kabel@kernel.org> 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 Thu, Jan 14, 2021 at 05:43:30AM +0100, Marek Behún wrote: > Instead of configuring the I2C mdiobus when SFP driver is probed, > create/destroy the mdiobus before the PHY is probed for/after it is > released. > > This way we can tell the mdio-i2c code which protocol to use for each > SFP transceiver. I've been thinking a bit more about this. It looks like it will allocate and free the MDIO bus each time any module is inserted or removed, even a fiber module that wouldn't ever have a PHY. This adds unnecessary noise to the kernel message log. We only probe for a PHY if one of: - id.base.extended_cc is SFF8024_ECC_10GBASE_T_SFI, SFF8024_ECC_10GBASE_T_SR, SFF8024_ECC_5GBASE_T, or SFF8024_ECC_2_5GBASE_T. - id.base.e1000_base_t is set. So, we only need the MDIO bus to be registered if one of those is true. As you are introducing "enum mdio_i2c_proto", I'm wondering whether that should include "MDIO_I2C_NONE", and we should only register the bus and probe for a PHY if it is not MDIO_I2C_NONE. Maybe we should have: enum mdio_i2c_proto { MDIO_I2C_NONE, MDIO_I2C_MARVELL_C22, MDIO_I2C_C45, MDIO_I2C_ROLLBALL, ... }; with: sfp->mdio_protocol = MDIO_I2C_NONE; if (((!memcmp(id.base.vendor_name, "OEM ", 16) || !memcmp(id.base.vendor_name, "Turris ", 16)) && (!memcmp(id.base.vendor_pn, "SFP-10G-T ", 16) || !memcmp(id.base.vendor_pn, "RTSFP-10", 8)))) { sfp->mdio_protocol = MDIO_I2C_ROLLBALL; sfp->module_t_wait = T_WAIT_ROLLBALL; } else { switch (id.base.extended_cc) { ... } } static int sfp_sm_add_mdio_bus(struct sfp *sfp) { int err = 0; if (sfp->mdio_protocol != MDIO_I2C_NONE) err = sfp_i2c_mdiobus_create(sfp); return err; } called from the place you call sfp_i2c_mdiobus_create(), and sfp_sm_probe_for_phy() becomes: static int sfp_sm_probe_for_phy(struct sfp *sfp) { int err = 0; switch (sfp->mdio_protocol) { case MDIO_I2C_NONE: break; case MDIO_I2C_MARVELL_C22: err = sfp_sm_probe_phy(sfp, SFP_PHY_ADDR, false); break; case MDIO_I2C_C45: err = sfp_sm_probe_phy(sfp, SFP_PHY_ADDR, true); break; case MDIO_I2C_ROLLBALL: err = sfp_sm_probe_phy(sfp, SFP_PHY_ADDR_ROLLBALL, true); break; } return err; } This avoids having to add the PHY address, as well as fudge around with id.base.extended_cc to get the PHY probed. Thoughts? -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last!