From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 3AF5015AC5 for ; Tue, 25 Jul 2023 10:08:28 +0000 (UTC) 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 38BD310CB for ; Tue, 25 Jul 2023 03:08:27 -0700 (PDT) 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=ZTG07ih6maDURnxD42sPRSsHT7XH4z+cZ7kTvarUF80=; b=YyUQ1kCc4XyZkxZHY5tochrYWX wd7k2n56PBb4rrqmV6iM7OFmUQliLVXyTzcduqi3WE46LGjiZErWkLnzz4jdq3HieZOQrEtpmSuCV kd4M9p42e3/7fvqrFq0E9brzjbn4Obw85b91putqfXJ7nCKXfiP4VcC+hXq1wSTs9mpL83ccaYOyq WJXfaDkJWFGklkuMsxztJHf+rk3QAWJAJ/YIQ5HDlGMjQNDE02DeS2E26mIx/rddpveivfPafJGau 68JsG9qISFoRrdo2KPSGhP9Uzg+2EhBuDEf53YJ5GyyWVAXQ6b8SkUD6x26s4e/VX923XnJGZP3k/ y4EN2GUA==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:42108) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1qOExs-0001sk-0V; Tue, 25 Jul 2023 11:08:24 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1qOExr-0001jA-8A; Tue, 25 Jul 2023 11:08:23 +0100 Date: Tue, 25 Jul 2023 11:08:23 +0100 From: "Russell King (Oracle)" To: Jiawen Wu Cc: netdev@vger.kernel.org, andrew@lunn.ch, hkallweit1@gmail.com, Jose.Abreu@synopsys.com, mengyuanlou@net-swift.com Subject: Re: [PATCH net-next 4/7] net: pcs: xpcs: adapt Wangxun NICs for SGMII mode Message-ID: References: <20230724102341.10401-1-jiawenwu@trustnetic.com> <20230724102341.10401-5-jiawenwu@trustnetic.com> <03cc01d9be9c$6e51cad0$4af56070$@trustnetic.com> <03f101d9bedd$763b06d0$62b11470$@trustnetic.com> 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: Sender: Russell King (Oracle) X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,SPF_HELO_NONE, SPF_NONE,T_SCC_BODY_TEXT_LINE,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On Tue, Jul 25, 2023 at 10:58:25AM +0100, Russell King (Oracle) wrote: > > The information obtained from the IC designer is that "PHY/MAC side SGMII" > > is configured by experimentation. For these different kinds of NICs: > > 1) fiber + SFP-RJ45 module: PHY side SGMII > > 2) copper (pcs + external PHY): MAC side SGMII > > This makes no sense. a PHY on a RJ45 SFP module is just the same as a > PHY integrated into a board with the MAC. MAC ---- PCS <----- sgmii -----> PHY (whether on a board or SFP) Control word flow: <------------------ link, speed, duplex ------------------> acknowledge (value = 0x4001) Sometimes, it's possible to connect two MACs/PCSs together: MAC ---- PCS <----- sgmii -----> PCS ---- MAC and in this case, one PCS would need to be configured in "MAC" mode and the other would need to be configured in "PHY" mode because SGMII is fundamentally asymmetric. Here is the definition of the control word sent by either end: Bit MAC->PHY PHY->MAC 15 0: Reserved Link status, 1 = link up 14 1: Acknowledge Reserved for AN acknowledge 13 0: Reserved 0: Reserved 12 0: Reserved Duplex mode 1 = full, 0 = half 11:10 0: Reserved Speed 11 = Reserved 10=1G, 01=100M, 00=10M 9:1 0: Reserved 0: Reserved 0 1 1 So my guess would be that "PHY side SGMII" means the device generates the "PHY->MAC" format word whereas "MAC side SGMII" generates the "MAC->PHY" format word - and it's the latter that you want to be using both for Copper SFPs, which are no different from PHYs integrated onto the board connected with SGMII. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!