From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754955AbeEHMqJ (ORCPT ); Tue, 8 May 2018 08:46:09 -0400 Received: from pandora.armlinux.org.uk ([78.32.30.218]:52540 "EHLO pandora.armlinux.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754444AbeEHMqI (ORCPT ); Tue, 8 May 2018 08:46:08 -0400 Date: Tue, 8 May 2018 13:45:53 +0100 From: Russell King - ARM Linux To: Andrew Lunn Cc: Florian Fainelli , mw@semihalf.com, ymarkman@marvell.com, jason@lakedaemon.net, Antoine Tenart , netdev@vger.kernel.org, gregory.clement@bootlin.com, kishon@ti.com, nadavh@marvell.com, linux-arm-kernel@lists.infradead.org, thomas.petazzoni@bootlin.com, miquel.raynal@bootlin.com, stefanc@marvell.com, maxime.chevallier@bootlin.com, davem@davemloft.net, linux-kernel@vger.kernel.org, sebastian.hesselbarth@gmail.com Subject: Re: [PATCH net-next v2 03/13] net: phy: sfp: warn the user when no tx_disable pin is available Message-ID: <20180508124553.GO16141@n2100.armlinux.org.uk> References: <20180504135643.23466-1-antoine.tenart@bootlin.com> <20180504135643.23466-4-antoine.tenart@bootlin.com> <20180504171425.GA17233@lunn.ch> <44545AF4-64E3-4772-B5BA-43CCF2321025@gmail.com> <20180505205242.GA2876@lunn.ch> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180505205242.GA2876@lunn.ch> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, May 05, 2018 at 10:52:42PM +0200, Andrew Lunn wrote: > On Sat, May 05, 2018 at 01:38:31PM -0700, Florian Fainelli wrote: > > On May 4, 2018 10:14:25 AM PDT, Andrew Lunn wrote: > > >On Fri, May 04, 2018 at 10:07:53AM -0700, Florian Fainelli wrote: > > >> On 05/04/2018 06:56 AM, Antoine Tenart wrote: > > >> > In case no Tx disable pin is available the SFP modules will always > > >be > > >> > emitting. This could be an issue when using modules using laser as > > >their > > >> > light source as we would have no way to disable it when the fiber > > >is > > >> > removed. This patch adds a warning when registering an SFP cage > > >which do > > >> > not have its tx_disable pin wired or available. > > >> > > >> Is this something that was done in a possibly earlier revision of a > > >> given board design and which was finally fixed? Nothing wrong with > > >the > > >> patch, but this seems like a pretty serious board design mistake, > > >that > > >> needs to be addressed. > > > > > >Hi Florian > > > > > >Zii Devel B is like this. Only the "Signal Detect" pin is wired to a > > >GPIO. > > > > > Good point, indeed. BTW what do you think about exposing the SFF's > > EEPROM and diagnostics through the standard ethtool operations even > > if we have to keep the description of the SFF as a fixed link in > > Device Tree because of the unfortunate wiring? > > I believe in Antoine case, all the control plane is broken. He cannot > read the EEPROM, nor any of the modules pins via GPIOs. Correct. > For Zii Devel B, the EEPROM is accessible, and so is the SD pin. What > is missing is transmit disable. So i would expose it as an SFF module. Agreed. -- RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ FTTC broadband for 0.8mile line in suburbia: sync at 8.8Mbps down 630kbps up According to speedtest.net: 8.21Mbps down 510kbps up