From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="sqnGbTdI" 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 867E2F5; Mon, 20 Nov 2023 08:18:20 -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=6SCBZOZz6Qup6QX990ipAzjI1yY+8rbPKPGIJ6ySC0E=; b=sqnGbTdIP9eiY5KVdCOGH68mSL OorK3g1mxqMHwNbBHJzmZcfhye06oLl9D7b2ucdzEubIu2uN7K/5btywoIHQon63OGbQX4+wib9Y0 r9zZuYEbWzRCNaP121etnyiXDueFvlXYvvlkeNTypWFZwyy8op+KMUUZngzSk1XGQ4IxW3ZeMthf8 5ixyIDuhokIU0GdZN3HQWBTnwNcHgBq2DUB4cg6QYKA60cU5qbduXITs9IXyoSTZKDlB6In1gUdX0 f5Z1V/OzX5wWjziNXN4L1CR1jORspQPJOx6eF2drxgSc3r6HJJ4aGkG8bunfLvS9YbYcUawr3B8ZP 5uoezByg==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:57710) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1r56yN-0005rP-1I; Mon, 20 Nov 2023 16:18:07 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1r56yN-0003JU-GV; Mon, 20 Nov 2023 16:18:07 +0000 Date: Mon, 20 Nov 2023 16:18:07 +0000 From: "Russell King (Oracle)" To: Andrew Lunn Cc: Jie Luo , davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, robh+dt@kernel.org, krzysztof.kozlowski+dt@linaro.org, conor+dt@kernel.org, hkallweit1@gmail.com, corbet@lwn.net, netdev@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org Subject: Re: [PATCH v5 3/6] net: phy: at803x: add QCA8084 ethernet phy support Message-ID: References: <20231118062754.2453-1-quic_luoj@quicinc.com> <20231118062754.2453-4-quic_luoj@quicinc.com> <1eb60a08-f095-421a-bec6-96f39db31c09@lunn.ch> <1d4d7761-6b42-48ec-af40-747cb4b84ca5@lunn.ch> Precedence: bulk X-Mailing-List: devicetree@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: <1d4d7761-6b42-48ec-af40-747cb4b84ca5@lunn.ch> Sender: Russell King (Oracle) On Mon, Nov 20, 2023 at 04:34:55PM +0100, Andrew Lunn wrote: > Are you saying there is a USXGMII-M level link change status? The link > between the SoC and the PHY package is up/down? If it is down, all > four MAC-PHY links are down. If it is up, it is possible to carry > frames between the SoC and the PHY package, but maybe the PHYs > themselves are down? It shouldn't do. Each "channel" in the USXGMII-M link has its own autoneg block at both ends, each conveys link status independently. The MAC side structure is: +----------+ +-----+ .-XGMII-> Rate | PCS | | MAC1 <-MDI-> PHY <-+ | Adaption <--> Clause 49 <-> | `-GMII--> | | | +-----^----+ | | | | | +-----v---- + | | | Autoneg | | | | Clause 37 | | | +-----------+ | | | Mux <--> PMA <--> | | ....... USXGMII-M <------------------------------------------------------> These blocks are repeated for each channel The spec goes on to state that there must be a USXGMII enable bit that defaults to disabled and the PHY should assume normal XGMII/XFI operation. When enabled, autoneg follows a slight modification of clause 37-6. As far as the USXGMII-M link, I believe 2.7.8 in the USXGMII-M documentation covers this, which is "hardware autoneg programming sequence". It states that "if 10G link is lost or regained, the software is expected to disable autoneg and re-enable autoneg". I think "10G link" refers to the USXGMII-M connection, which means the loss of that link shold cause software to intervene in each of the PCS autoneg blocks. It is, however, rather unclear. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!