RE: [EXT] Re: [PATCH net-next 02/10] net: phy: phylink: allow 10GKR interface to use in-band negotiation

[Yan Markman]

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 <linux@xxxxxxxxxxxxxxx>; Antoine Tenart <antoine.tenart@xxxxxxxxxxx>
Cc: davem@xxxxxxxxxxxxx; kishon@xxxxxx; gregory.clement@xxxxxxxxxxx; andrew@xxxxxxx; jason@xxxxxxxxxxxxxx; sebastian.hesselbarth@xxxxxxxxx; netdev@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; thomas.petazzoni@xxxxxxxxxxx; maxime.chevallier@xxxxxxxxxxx; miquel.raynal@xxxxxxxxxxx; Nadav Haklai <nadavh@xxxxxxxxxxx>; Yan Markman <ymarkman@xxxxxxxxxxx>; mw@xxxxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx
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/

Stefan,
Best Regards.

Attachment: 0001-arm64-dts-marvell-add-new-mcbin-single-shot-board.patch
Description: 0001-arm64-dts-marvell-add-new-mcbin-single-shot-board.patch