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From:   Stefan Chulski <stefanc@marvell.com>
To:     Russell King - ARM Linux <linux@armlinux.org.uk>,
        Antoine Tenart <antoine.tenart@bootlin.com>
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Subject: RE: [EXT] Re: [PATCH net-next 02/10] net: phy: phylink: allow 10GKR
 interface to use in-band negotiation
Thread-Topic: [EXT] Re: [PATCH net-next 02/10] net: phy: phylink: allow 10GKR
 interface to use in-band negotiation
Thread-Index: AQHTvT77nBQG5ffkBEaqTn9C4RyF8qPXI08AgAAm5YCAAD44wA==
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>
In-Reply-To: <20180319111205.GB2743@n2100.armlinux.org.uk>
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> > > 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.