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 DDA1C6D3F for ; Fri, 14 Jul 2023 08:45:25 +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 4F0CF358C for ; Fri, 14 Jul 2023 01:45:20 -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-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=UDJewWYcEeJZnjMf8M0jQDqFbjUDAXj3G8pl/YBv3qc=; b=0sIdpWnFuzPSnbx8/EzZMlZ2Wi Xx9sKH10DvSKaR0UWV+99UEvZvNsITYr9cG63+diBXL3NRRZN7TnHx/R+3vJ51gx33kz+VKhWIGgb RfcJQNSVV62bTGDQjv+TKIGsxEqN7x4HSy2SS4swmg7oHo8i1i97DMp21a1W9szuDXGJ7R9TtBTsN RS97qH7cB3IzRuHuwTd3zxh1JtyZZKh1aGdJkFMoMpTgW+FT/8FZPw772a+Qxf5DfBZXCI0ODERhl hjURwEiuis304s5ali+VB35gymO+Z0Mx/WcNGhTied+k9lb3MHG+XuZEdna2KCAGFrIX+PMNrsbMg vwPgnQkg==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:40442) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1qKEQH-0000If-0b; Fri, 14 Jul 2023 09:45:09 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1qKEQF-00074D-7H; Fri, 14 Jul 2023 09:45:07 +0100 Date: Fri, 14 Jul 2023 09:45:07 +0100 From: "Russell King (Oracle)" To: Feiyang Chen Cc: Andrew Lunn , Feiyang Chen , hkallweit1@gmail.com, peppe.cavallaro@st.com, alexandre.torgue@foss.st.com, joabreu@synopsys.com, chenhuacai@loongson.cn, dongbiao@loongson.cn, loongson-kernel@lists.loongnix.cn, netdev@vger.kernel.org, loongarch@lists.linux.dev Subject: Re: [RFC PATCH 10/10] net: stmmac: dwmac-loongson: Add GNET support Message-ID: References: <98b53d15bb983c309f79acf9619b88ea4fbb8f14.1689215889.git.chenfeiyang@loongson.cn> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit 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 Fri, Jul 14, 2023 at 10:24:37AM +0800, Feiyang Chen wrote: > On Thu, Jul 13, 2023 at 12:07 PM Andrew Lunn wrote: > > > > On Thu, Jul 13, 2023 at 10:49:38AM +0800, Feiyang Chen wrote: > > > Add GNET support. Use the fix_mac_speed() callback to workaround > > > issues with the Loongson PHY. > > > > What are the issues? > > > > Hi, Andrew, > > There is an issue with the synchronization between the network card > and the PHY. In the case of gigabit operation, if the PHY's speed > changes, the network card's speed remains unaffected. Hence, it is > necessary to initiate a re-negotiation process with the PHY to align > the link speeds properly. Please could you explain a bit more what happens when "the PHY's speed changes". Are you suggesting that: You have a connection where the media side has negotiated 1G speed. The gigabit partner is disconnected, so the link goes down, and is then replaced by a partner only capable of 100M. The link comes back up at 100M, but the network card continues trying to operate at 1G? Thanks. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!