From mboxrd@z Thu Jan 1 00:00:00 1970 From: Russell King - ARM Linux 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 13:05:57 +0000 Message-ID: <20180319130556.GC2743@n2100.armlinux.org.uk> 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> <4e11135ba2644f76beb41a307c9d990a@IL-EXCH01.marvell.com> <2ff0a81f55a84069a4652d02a4212b70@IL-EXCH01.marvell.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Stefan Chulski , Antoine Tenart , "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 , "mw@semihalf.com" , "linux-arm-kernel@lists.infradea To: Yan Markman Return-path: Content-Disposition: inline In-Reply-To: <2ff0a81f55a84069a4652d02a4212b70@IL-EXCH01.marvell.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Mon, Mar 19, 2018 at 01:01:07PM +0000, Yan Markman wrote: > The DTS-patch for this board (in "old" format) is attached > > > Yan Markman > Tel. 05-44732819 > > > -----Original Message----- > From: Stefan Chulski > Sent: Monday, March 19, 2018 2:58 PM > To: Russell King - ARM Linux ; Antoine Tenart > 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 > Subject: RE: [EXT] Re: [PATCH net-next 02/10] net: phy: phylink: allow 10GKR interface to use in-band negotiation > > > > > 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/ Correct, but this DTS is wrong. It connects to a SFP cage, and as SFP cages are supported in mainline now, there's no need to mess around with fixed links or similar. I haven't tested phylink in that configuration yet as SolidRun haven't sent me a SingleShot board yet - and I need any board I do get to have the pull-up resistors on the I2C lines of the correct value, because I'm not risking corruption of the EEPROMs in my SFP* modules. -- 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