From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6254A213E6D; Fri, 30 May 2025 07:46:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.32.30.218 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748591198; cv=none; b=fzrDYBiLR4e5ewANl9mGxdmXXWkLgRtj1ImtVKNuhxgAoP2RE08pVDtJiM/w3tmeekmbMOIiKU0eNKyzr/pv/Y1TgDty/LSHDm5aHZTYuwyhdv0wrOUmxAerjR4zEM/cbzrl0pEASCmRDu0xLoURAdlWvUlP5gcDpGhH0FI1eOc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1748591198; c=relaxed/simple; bh=C/gy27BDlYkIDsDi2lK2NXljjmhG5IvM8N89F5XHS3M=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=REoS21j7QnCTXl/QT9aZ6FjkyYngocj/tHd9G3l+rtvjx27sj1oQyE7lp2FUE/TcYTXPh/lN2gUxuEK64rH+1bPsY3wfammLAwclYL2r0Paz6Mxvw41IWs7Qz1bQV1wrEWPen0uqtnKHy1l3M/6ziQo4bP95ZeR7Io1wNEsEZGU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk; spf=none smtp.mailfrom=armlinux.org.uk; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b=O/mKfuQB; arc=none smtp.client-ip=78.32.30.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="O/mKfuQB" 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=Ut2tpuuqRAyjo9B+qNNd6yMUFNVjo/29ecFKGIED0ig=; b=O/mKfuQB0BUcNmKRdmWHnd9iSG YG+hJVA3Yn5K2Cyf7t9KIzf9KxAnua8o59fak2AfljqKfB8sgaL/fJtW/VJHi+0FT0XD14AO/yh0h WBYb4GNg8RPO6rM8zhtWY1VqZe77B8ZTC6DS34hH2Lje4+TY59ss4FN9jqBaXeyHrHMS089dZy7IO v6tIHTswLxoPoyt4C75BFzlOtlJqTBYYKJ+BuahW0po4IZOKX596tYectV7YVC0scKjOZXFK9o3uM Du8yGWMTEI5Wq0NzmCH2n21bMfmg6tTQ/LbkC/7mjUgqnyIKNEpS0AlTSXjs1pNNCiYYZTfoCFKxs d4ZMt7sg==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:40490) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1uKuRe-00027t-2K; Fri, 30 May 2025 08:46:26 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.96) (envelope-from ) id 1uKuRX-0004Rl-1d; Fri, 30 May 2025 08:46:19 +0100 Date: Fri, 30 May 2025 08:46:19 +0100 From: "Russell King (Oracle)" To: Romain Gantois Cc: Maxime Chevallier , davem@davemloft.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, thomas.petazzoni@bootlin.com, Andrew Lunn , Jakub Kicinski , Eric Dumazet , Paolo Abeni , linux-arm-kernel@lists.infradead.org, Christophe Leroy , Herve Codina , Florian Fainelli , Heiner Kallweit , Vladimir Oltean , =?iso-8859-1?Q?K=F6ry?= Maincent , Marek =?iso-8859-1?Q?Beh=FAn?= , Oleksij Rempel , =?iso-8859-1?Q?Nicol=F2?= Veronese , Simon Horman , mwojtas@chromium.org, Antoine Tenart , devicetree@vger.kernel.org, Conor Dooley , Krzysztof Kozlowski , Rob Herring , Daniel Golle , Dimitri Fedrau Subject: Re: [PATCH net-next v6 06/14] net: phy: Introduce generic SFP handling for PHY drivers Message-ID: References: <20250507135331.76021-1-maxime.chevallier@bootlin.com> <13770694.uLZWGnKmhe@fw-rgant> <6159237.lOV4Wx5bFT@fw-rgant> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6159237.lOV4Wx5bFT@fw-rgant> Sender: Russell King (Oracle) On Fri, May 30, 2025 at 09:28:11AM +0200, Romain Gantois wrote: > On Thursday, 29 May 2025 15:23:22 CEST Russell King (Oracle) wrote: > > On Wed, May 28, 2025 at 09:35:35AM +0200, Romain Gantois wrote: > > > > In that regard, you can consider 1000BaseX as a MII mode (we do have > > > > PHY_INTERFACE_MODE_1000BASEX). > > > > > > Ugh, the "1000BaseX" terminology never ceases to confuse me, but yes > > > you're > > > right. > > > > 1000BASE-X is exactly what is described in IEEE 802.3. It's a PHY > > interface mode because PHYs that use SerDes can connect to the host > > using SGMII or 1000BASE-X over the serial link. > > > > 1000BASE-X's purpose in IEEE 802.3 is as a protocol for use over > > fibre links, as the basis for 1000BASE-SX, 1000BASE-LX, 1000BASE-EX > > etc where the S, L, E etc are all to do with the properties of the > > medium that the electrical 1000BASE-X is sent over. It even includes > > 1000BASE-CX which is over copper cable. > > Ah makes sense, thanks for the explanation. I guess my mistake was assuming > that MAC/PHY interface modes were necessarily strictly at the reconciliation > sublayer level, and didn't include PCS/PMA functions. When a serdes protocol such as SGMII, 1000BASE-X, or 10GBASE-R is being used with a PHY, the IEEE 802.3 setup isn't followed exactly - in effect there are more layers. On the SoC: MAC Reconciliation (RS) PCS SerDes (part of the PMA layer) On the PHY side of the SerDes host-to-phy link: SerDes PCS (which may or may not be exposed in the PHY register set, and is normally managed by the PHY itself) (maybe other layers, could include MACs back-to-back) PCS PMA PMD Hope that helps explain what's going on a little more. Another way to look at it is that with SGMII, 1000BASE-X etc between the PHY and host, the PHY is a media converter. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!