From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Chulski Subject: RE: [EXT] Re: [PATCH net-next 02/10] net: phy: phylink: allow 10GKR interface to use in-band negotiation Date: Mon, 19 Mar 2018 12:58:24 +0000 Message-ID: <4e11135ba2644f76beb41a307c9d990a@IL-EXCH01.marvell.com> References: <20180316103351.16616-1-antoine.tenart@bootlin.com> <20180316103351.16616-3-antoine.tenart@bootlin.com> <20180316155307.GQ9418@n2100.armlinux.org.uk> <20180319085252.GF4519@kwain> <20180319111205.GB2743@n2100.armlinux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 8BIT Cc: "davem@davemloft.net" , "kishon@ti.com" , "gregory.clement@bootlin.com" , "andrew@lunn.ch" , "jason@lakedaemon.net" , "sebastian.hesselbarth@gmail.com" , "netdev@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "thomas.petazzoni@bootlin.com" , "maxime.chevallier@bootlin.com" , "miquel.raynal@bootlin.com" , Nadav Haklai , Yan Markman , "mw@semihalf.com" , "linux-arm-kernel@lists.infradead.org" To: Russell King - ARM Linux , Antoine Tenart Return-path: In-Reply-To: <20180319111205.GB2743@n2100.armlinux.org.uk> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org > > > There is no inband negotiation like there is with 802.3z or SGMII, > > > so this makes no sense. > > > > Oh, that's what I feared. I read some docs but probably will need more > > :) > > > > Anyway, the reason to use in-band negotiation was also to avoid using > > fixed-link. It would work but always report the link is up, which for > > the user isn't a great experience as we have a way to detect this. > > > > What would you suggest to achieve this in a reasonable way? > > The intention of this test in phylink_of_phy_connect() is to avoid failing > when there is no requirement for a PHY to be present (such as a fixed link, or > an 802.3z link.) However, with 10G PHYs such as the 3310, we need the PHY > so we can read the speed from it, and so know whether to downgrade the > MAC to SGMII mode, or having downgraded the MAC, upgrade it back to 10G > mode when the PHY switches to 10G. > > I'm guessing that you're wanting this for the DB boards, but I don't see why. > Do they not have PHYs? New Solid Run board MACCHIATObin Single Shot doesn't has 3310 PHY either, like DB boards. https://www.cnx-software.com/2017/12/20/solidrun-macchiatobin-single-shot-networking-board-launched-for-269-and-up/ Stefan, Best Regards.