From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Lunn Subject: Re: [PATCH net-next 1/3] ethtool: (uapi) Add ETHTOOL_PHY_LOOPBACK to PHY tunables Date: Mon, 28 Nov 2016 15:14:10 +0100 Message-ID: <20161128141410.GF4379@lunn.ch> References: <1480339472-5823-1-git-send-email-allan.nielsen@microsemi.com> <1480339472-5823-2-git-send-email-allan.nielsen@microsemi.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: netdev@vger.kernel.org, f.fainelli@gmail.com, raju.lakkaraju@microsemi.com To: "Allan W. Nielsen" Return-path: Received: from vps0.lunn.ch ([178.209.37.122]:59714 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933125AbcK1OOM (ORCPT ); Mon, 28 Nov 2016 09:14:12 -0500 Content-Disposition: inline In-Reply-To: <1480339472-5823-2-git-send-email-allan.nielsen@microsemi.com> Sender: netdev-owner@vger.kernel.org List-ID: On Mon, Nov 28, 2016 at 02:24:30PM +0100, Allan W. Nielsen wrote: > From: Raju Lakkaraju > > 3 types of PHY loopback are supported. > i.e. Near-End Loopback, Far-End Loopback and External Loopback. Hi Allan Is this integrated with ethtool --test? You only want the PHY to go into loopback mode when running ethtool --test external_lb or maybe ethtool --test offline. What i think should happen is that this tunable sets the mode the PHY will go into when loopback is enabled. It does not however enable loopback. It is running ethtool --test which actually enables the loopback, probably by setting BMCR_LOOPBACK. Once the test is finished, the bit is cleared and the PHY goes back into normal operation. Andrew