From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andrew Lunn Subject: Re: [PATCH net-next 0/3] ethtool: support for forward error correction mode setting on a link Date: Sat, 24 Jun 2017 23:47:42 +0200 Message-ID: <20170624214742.GO4875@lunn.ch> References: <1498331985-8525-1-git-send-email-roopa@cumulusnetworks.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: davem@davemloft.net, linville@tuxdriver.com, netdev@vger.kernel.org, vidya.chowdary@gmail.com, dustin@cumulusnetworks.com, olson@cumulusnetworks.com, leedom@chelsio.com, manojmalviya@chelsio.com, santosh@chelsio.com, yuval.mintz@qlogic.com, odedw@mellanox.com, ariela@mellanox.com, galp@mellanox.com, jeffrey.t.kirsher@intel.com To: Roopa Prabhu Return-path: Received: from vps0.lunn.ch ([178.209.37.122]:34064 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752238AbdFXVry (ORCPT ); Sat, 24 Jun 2017 17:47:54 -0400 Content-Disposition: inline In-Reply-To: <1498331985-8525-1-git-send-email-roopa@cumulusnetworks.com> Sender: netdev-owner@vger.kernel.org List-ID: On Sat, Jun 24, 2017 at 12:19:42PM -0700, Roopa Prabhu wrote: > From: Roopa Prabhu > > Forward Error Correction (FEC) modes i.e Base-R > and Reed-Solomon modes are introduced in 25G/40G/100G standards > for providing good BER at high speeds. Various networking devices > which support 25G/40G/100G provides ability to manage supported FEC > modes and the lack of FEC encoding control and reporting today is a > source for itneroperability issues for many vendors. interoperability. The same typ0 exists in the first patch > FEC capability as well as specific FEC mode i.e. Base-R > or RS modes can be requested or advertised through bits D44:47 of base link > codeword. For my own education, is this logically a MAC or a PHY thing? Is the negotiation performed at the PHY level, and then FEC happens at the MAC level? I'm just trying to look ahead when we start getting 25G/40G/100G PHY support. Does phylib need an extension, similar to how pause is negotiated at the PHY, and then the MAC does the actual work? Andrew