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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 D2C45C433DB for ; Thu, 7 Jan 2021 14:52:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8725A217A0 for ; Thu, 7 Jan 2021 14:52:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728233AbhAGOwY (ORCPT ); Thu, 7 Jan 2021 09:52:24 -0500 Received: from vps0.lunn.ch ([185.16.172.187]:55214 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726165AbhAGOwX (ORCPT ); Thu, 7 Jan 2021 09:52:23 -0500 Received: from andrew by vps0.lunn.ch with local (Exim 4.94) (envelope-from ) id 1kxWdW-00Ggmn-JW; Thu, 07 Jan 2021 15:51:38 +0100 Date: Thu, 7 Jan 2021 15:51:38 +0100 From: Andrew Lunn To: Greg KH Cc: Xu Yilun , arnd@arndb.de, lee.jones@linaro.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, trix@redhat.com, lgoncalv@redhat.com, hao.wu@intel.com, matthew.gerlach@intel.com, russell.h.weight@intel.com Subject: Re: [RESEND PATCH 2/2] misc: add support for retimers interfaces on Intel MAX 10 BMC Message-ID: References: <1609999628-12748-1-git-send-email-yilun.xu@intel.com> <1609999628-12748-3-git-send-email-yilun.xu@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 07, 2021 at 10:26:12AM +0100, Greg KH wrote: > On Thu, Jan 07, 2021 at 02:07:08PM +0800, Xu Yilun wrote: > > This driver supports the ethernet retimers (C827) for the Intel PAC > > (Programmable Acceleration Card) N3000, which is a FPGA based Smart NIC. > > > > C827 is an Intel(R) Ethernet serdes transceiver chip that supports > > up to 100G transfer. On Intel PAC N3000 there are 2 C827 chips > > managed by the Intel MAX 10 BMC firmware. They are configured in 4 ports > > 10G/25G retimer mode. Host could query their link states and firmware > > version information via retimer interfaces (Shared registers) on Intel > > MAX 10 BMC. The driver creates sysfs interfaces for users to query these > > information. > > Networking people, please look at this sysfs file: > > > +What: /sys/bus/platform/devices/n3000bmc-retimer.*.auto/link_statusX > > +Date: Jan 2021 > > +KernelVersion: 5.12 > > +Contact: Xu Yilun > > +Description: Read only. Returns the status of each line side link. "1" for > > + link up, "0" for link down. > > + Format: "%u". > > as I need your approval to add it because it is not the "normal" way for > link status to be exported to userspace. Hi Greg Correct, this is not going to be acceptable. The whole architecture needs to cleanly fit into the phylink model for controlling the SFP and the retimer. I'm guessing Intel needs to rewrite portions of the BMC firmware to either transparently pass through access to the SFP socket and the retimer for phylink and a C827 specific driver, or add a high level API which a MAC driver can use, and completely hide away these PHY details from Linux, which is what many of the Intel Ethernet drivers do. Andrew