From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from vps0.lunn.ch (vps0.lunn.ch [156.67.10.101]) (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 64B764CC600; Fri, 25 Sep 2026 15:17:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=156.67.10.101 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790349475; cv=none; b=T8xTUeDIjr6Zhme2XwHCqApeZcblDys/C8CNlyN+fM8xb12jNEKHi9s2R0gBTB3GrLEmZjGpwPeNDNFVYBkOOCJ+mxHtA8FyVVIrp+3um7Ui9Oh/nXZ966RAPz9c/4GQqDPRPFMvpCdyT21jCqwP8Aya4PDnVET+8of3ngYxoCQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790349475; c=relaxed/simple; bh=r4jHvC8R1qGwo2iO+ASqWnDSlAhMX54J1FPDrWj5w1U=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=U0e2siTCQ1Kt2ksybdjWAPZVGJl6IzRlF/9ngTiUCNw7RKlHuBedMoIzmyBNEwUtsPa2vCqVBh7kb6rBV57ugmFWh2u3IAZyEEdh4VME/5SX4tTRRXrM3OtGpNOH+6l1P+IWWNN5PaG5dybGSCjoKs6982u26jlJhbM1XjdivUo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch; spf=pass smtp.mailfrom=lunn.ch; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b=ycp3L/Y3; arc=none smtp.client-ip=156.67.10.101 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=lunn.ch Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lunn.ch Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="ycp3L/Y3" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Disposition:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:From:Sender:Reply-To:Subject: Date:Message-ID:To:Cc:MIME-Version:Content-Type:Content-Transfer-Encoding: Content-ID:Content-Description:Content-Disposition:In-Reply-To:References; bh=TPq2jWBG+cE1Qwr/PmJfAp3LKpTg+6qSkEgMYh+YGc0=; b=ycp3L/Y3vWB3aD5bsRmZ5a0boe KKL26JRrRMZ9gXVAdzCPSHWQMzW8ZOOGWruL+clZkU2YLNEi86sIILtCe+j+Yl+jfMJAhVkNAWklb Dfk7Vbb6dRyulZzgfTfDBVAzIQt69VSnhe9IkBuhlNmYomlmZM3Z5djjC1hLcpHamxZ8=; Received: from andrew by vps0.lunn.ch with local (Exim 4.94.2) (envelope-from ) id 1xA7g5-007ExF-MU; Fri, 25 Sep 2026 17:17:33 +0200 Date: Fri, 25 Sep 2026 17:17:33 +0200 From: Andrew Lunn To: Yongzhao Chen Cc: netdev@vger.kernel.org, "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Florian Fainelli , Vladimir Oltean , Christian Marangi , Heiner Kallweit , Russell King , linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, Ziyang Huang Subject: Re: [RFC PATCH net-next v3 4/5] net: dsa: qca8k: flag QCA8337 internal CPU PHYs for SmartSpeed Message-ID: References: <20260923215858.1653-1-yongzhao.derek@gmail.com> <20260923215858.1653-5-yongzhao.derek@gmail.com> <09d669ff-7aad-4414-880a-21c2e7bf2cd7@lunn.ch> <20260924234814.1734-1-yongzhao.derek@gmail.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: <20260924234814.1734-1-yongzhao.derek@gmail.com> > I don't know whether downshift is broken in general or only in > switch-integrated PHYs. My only data point is the RA74 CPU link > failure, and I have no downshift results from user ports or discrete > at803x PHYs. It is pretty easy to test, if you have a spare Ethernet cable you can sacrifice. https://en.wikipedia.org/wiki/Ethernet_over_twisted_pair 100Mbps needs pins 1-4, 5-8 are not used. So you can either cover some of those pins with something, maybe nail varnish, or take some of the outer cover off the cable to expose the wires, and if it follows the colour scheme describe cut say the brown cable. But this is testing the wrong thing. This is testing downshift works. What you are actually interested in is downshift happening when it should not.... So take a closer look at the user ports. phylib should report when a downshift occurs: https://elixir.bootlin.com/linux/v7.2.7/source/drivers/net/phy/phy-core.c#L359 phydev->advertising should contain what the user configured, even if the hardware has cleared the 1G advertisement. So it should trigger. Andrew