From: "Marek Behún" <kabel@kernel.org>
To: Russell King - ARM Linux admin <linux@armlinux.org.uk>
Cc: andrew@lunn.ch, netdev@vger.kernel.org, olteanv@gmail.com,
pavana.sharma@digi.com
Subject: Re: mv88e6xxx: 2500base-x inband AN is broken on Amethyst? what to do?
Date: Wed, 13 Jan 2021 22:37:29 +0100 [thread overview]
Message-ID: <20210113223729.33c8bb65@kernel.org> (raw)
In-Reply-To: <20210113212125.GJ1551@shell.armlinux.org.uk>
On Wed, 13 Jan 2021 21:21:25 +0000
Russell King - ARM Linux admin <linux@armlinux.org.uk> wrote:
> > Russell, could we, for now, just edit the code so that when
> > mv88e6390_serdes_pcs_config
> > is being configured with inband mode in 2500base-x, the inband mode
> > won't be enabled and the function will print a warning?
> > This could come with a Fixes tag so that it is backported to stable.
>
> I don't see any other easy option, so yes, please do that.
Will do.
> > Afterwards we can work on refactoring the phylink code so that either
> > the driver can inform phylink whether 2500base-x inband AN is supported,
> > or maybe we can determine from some documentation or whatnot whether
> > inband AN is supported on 2500base-x at all.
>
> I suspect there is no definitive documentation on exactly what
> 2500base-x actually is. I suspect it may just be easier to turn off AN
> for 2500base-x everywhere, so at least all Linux systems are compatible
> irrespective of the hardware.
>
> Yes, it means losing pause negotiation, and people will have to
> manually set pause on each end.
This would need a little refactoring of the phylink_sfp_config
function, but I don't think it will be that hard.
> One thing that I don't know is whether the GPON SFP ONT modules that
> use 2500base-x will still function with AN disabled - although I have
> the modules, it appeared that they both needed a connection to the ONU
> to switch from 1000base-x to 2500base-x on the host side - and as I
> don't have an ONU I can test with, I have no way to check their
> behaviour.
We have an ISP here in Prague who is willing to lend us some GPON
ONU devices to get GPON SFP modules work on Turris. I will ask him if he
has one capable of 2.5g and try to borrow it.
Marek
next prev parent reply other threads:[~2021-01-14 2:14 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-13 0:18 mv88e6xxx: 2500base-x inband AN is broken on Amethyst? what to do? Marek Behún
2021-01-13 4:22 ` Marek Behun
2021-01-13 10:28 ` Russell King - ARM Linux admin
2021-01-13 17:03 ` Marek Behún
2021-01-13 20:08 ` Marek Behún
2021-01-13 21:21 ` Russell King - ARM Linux admin
2021-01-13 21:37 ` Marek Behún [this message]
2021-01-13 21:48 ` Russell King - ARM Linux admin
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