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 8B095F9C5 for ; Wed, 26 Jul 2023 15:29:44 +0000 (UTC) Received: from pandora.armlinux.org.uk (unknown [IPv6:2001:4d48:ad52:32c8:5054:ff:fe00:142]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3E5CD2137 for ; Wed, 26 Jul 2023 08:29:43 -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=BjrSQ5IKcciLqpEbqlMKfz6FUHHN3vwxCeK/ewwtna4=; b=TaPWC+C+4uIwdrOzp/Om38TvyX raBlxmx3U4JM1EKRP62aTIA1WVTSZdRD18lH/V1yY/xY7jMr13RRK3lU+nUNUZqHy/oZ0KOSGytzD pmtarKSR3aIEIKRDw3c5C6OpS706E6iqL0vJo4D4KFPjKzLukKaiBapDikz1cL5cbGVan+dhQMQkt SLp08qTpwplSvChhladPL2mnySpOyVYqMtjWyUBUVCsfwfLtA1eclUxJSSZxFv/brgGgy2G5GldBM A40IAwnQxmtz/xyC9Nv1BF18QHAPq2lr1UKzhUpHVAFLPlA/r2qe4gJ8kmt89Oo9R5AGCLZrATBjO XLulJ8fg==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:40774) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1qOgS6-0004dh-2x; Wed, 26 Jul 2023 16:29:26 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1qOgS5-0002yX-BF; Wed, 26 Jul 2023 16:29:25 +0100 Date: Wed, 26 Jul 2023 16:29:25 +0100 From: "Russell King (Oracle)" To: Shenwei Wang Cc: Vladimir Oltean , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Maxime Coquelin , Shawn Guo , dl-linux-imx , Giuseppe Cavallaro , Alexandre Torgue , Jose Abreu , Sascha Hauer , Pengutronix Kernel Team , Fabio Estevam , "netdev@vger.kernel.org" , "linux-stm32@st-md-mailman.stormreply.com" , "linux-arm-kernel@lists.infradead.org" , "imx@lists.linux.dev" , Frank Li Subject: Re: [EXT] Re: [PATCH] net: stmmac: dwmac-imx: pause the TXC clock in fixed-link Message-ID: References: <20230725194931.1989102-1-shenwei.wang@nxp.com> <20230726004338.6i354ue576hb35of@skbuf> 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=-3.6 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED,RDNS_NONE, 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 Wed, Jul 26, 2023 at 03:10:19PM +0000, Shenwei Wang wrote: > > if (of_phy_is_fixed_link(dwmac->dev->of_node)) { > > > > This does not help in this case. What I need to determine is if the PHY currently in use is a fixed-link. > The dwmac DTS node may have multiple PHY nodes defined, including both fixed-link and real PHYs. ... and this makes me wonder what DT node structure you think would describe a fixed-link. A valid ethernet device node would be: dwmac-node { phy-handle = <&phy1>; }; In this case: dwmac->dev->of_node points at "dwmac-node" plat->phylink_node points at "dwmac-node" plat->phy_node points at "phy1" Your "dn" is NULL. Therefore, your imx_dwmac_is_fixed_link() returns false. dwmac-node { fixed-link { speed = <...>; full-duplex; }; }; In this case: dwmac->dev->of_node points at "dwmac-node" plat->phylink_node points at "dwmac-node" plat->phy_node is NULL Your "dn" points at the "fixed-link" node. Therefore, your imx_dwmac_is_fixed_link() also returns false. Now, as far as your comment "What I need to determine is if the PHY currently in use is a fixed-link." I'm just going "Eh? What?" at that, because it makes zero sense to me. stmmac uses phylink. phylink doesn't use a PHY for fixed-links, unlike the old phylib-based fixed-link implementation that software-emulated a clause-22 PHY. With phylink, when fixed-link is specified, there is _no_ PHY. There is no need to do any of this poking about to determine if the link that is being brought up is a fixed-link or not, because phylink's callbacks into the MAC driver already contain this information in the "mode" argument. However, that is not passed to the driver's internal priv->plat->fix_mac_speed() method - but this is the information you need. There is no need to write code to try and second-guess this, phylink tells drivers what mode it is operating under. stmmac really needs to be cleaned up - and really doesn't need more complexity when the information is already being provided to the driver. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!