From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5D9DEC43381 for ; Thu, 21 Mar 2019 08:38:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 25B6A218B0 for ; Thu, 21 Mar 2019 08:38:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="2Cko+qTq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727931AbfCUIic (ORCPT ); Thu, 21 Mar 2019 04:38:32 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:32955 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727859AbfCUIic (ORCPT ); Thu, 21 Mar 2019 04:38:32 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender: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=YFfLn496gXJyvMZPDHSscs/MLcK5Ip2kExpt1XuNLoA=; b=2Cko+qTqpkQ+19mWi5bFiC1hKY pO3HkWGyrgTmTmKaK+7uip9JcIIFYBtW0waz/xCwYcxDgyy7VkvJ3O04pUcW+Dk1vAvZ1+YkCq/Wt aRHsypvHxfDyBqXVILQscouHgvQTt838TFOqkSmOaYqQgmVAXccVpSAtx+M4IzzdEeyY=; Received: from andrew by vps0.lunn.ch with local (Exim 4.89) (envelope-from ) id 1h6tDX-0001W4-9g; Thu, 21 Mar 2019 09:38:27 +0100 Date: Thu, 21 Mar 2019 09:38:27 +0100 From: Andrew Lunn To: Heiner Kallweit Cc: Florian Fainelli , David Miller , "netdev@vger.kernel.org" Subject: Re: [PATCH net-next] net: phy: aquantia: add downshift support Message-ID: <20190321083827.GD2900@lunn.ch> References: <1d3111d4-5af9-0611-8642-b5f29067651e@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1d3111d4-5af9-0611-8642-b5f29067651e@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Wed, Mar 20, 2019 at 10:15:10PM +0100, Heiner Kallweit wrote: > Aquantia PHY's of the AQR107 family support the downshift feature. > Add support for it as standard PHY tunable so that it can be controlled > via ethtool. > The AQCS109 supports a proprietary 2-pair 1Gbps mode. If two such PHY's > are connected to each other with a 2-pair cable, they may not be able > to establish a link if both advertise modes >= 1Gbps. Therefore enable > downshift per default on this model. Hi Heiner Is there any way to know it has done a downshift? Florian said the Intel drivers print a message when they downshift. It could be interesting to know, especially when a PHY goes from 1G to 100M. Even for a downshift to 1000Base-T2, i'm guessing for most use cases, this means the cable is partially broken, and it serves as an early warning it needs replacing. Andrew