[Macchiato] SFP+ ports - any config needed?

[Steve McIntyre]

Hey Baruch,

On Sun, Dec 16, 2018 at 01:21:30PM +0200, Baruch Siach wrote:
>Steve McIntyre writes:
>> I've just got a new switch with some 10G SFP+ ports on it, and I'm
>> trying to use it with my macchiatobin, with some simple SFP+ direct
>> attach cables.
>>
>> Naively, I just plugged things together and hoped for the best. *grin*
>> But I don't seem to be getting any link on my cable. I don't see any
>> obvious way of configuring the two 10G ports to use the SFP+ cages
>> rather than the RJ45 TP connectors. Can somebody tell me what I'm
>> missing please? Marcin?
>
>Which kernel version are you using?

Debian's 4.18 backports kernel, which is "4.18.6-1~bpo9+1".

>Do you have CONFIG_SFP and CONFIG_MARVELL_10G_PHY enabled?

Yup.

>You might need kernel commit 01b3fd5ac97c ("net: mvpp2: fix detection of
>10G SFP modules") from v4.20-rc6 for 10G configuration.

Hmm, OK. Will take a look.

>To the best of my knowledge the 10G PHY automatically selects the active
>port between copper and SFP.

OK, cool. I was a little thrown by ethtool not showing anything under
supported ports for the 10G SFP+ ports, but showing odd settings for
the others:

root at mjolnir:/lib/modules# ethtool eth0 | grep "Supported ports"
        Supported ports: [ ]
root at mjolnir:/lib/modules# ethtool eth1 | grep "Supported ports"
        Supported ports: [ ]
root at mjolnir:/lib/modules# ethtool eth2 | grep "Supported ports"
        Supported ports: [ TP MII FIBRE ]
root at mjolnir:/lib/modules# ethtool eth3 | grep "Supported ports"
        Supported ports: [ MII ]

Whereas on other machines with SFP+ I see FIBRE, and more sensible
looking options elswhere:

root at mustang3:/home/steve# ethtool eth0 | grep "Supported ports"
        Supported ports: [ TP MII ]
root at mustang3:/home/steve# ethtool eth1 | grep "Supported ports"
        Supported ports: [ TP MII ]
root at mustang3:/home/steve# ethtool eth2 | grep "Supported ports"
        Supported ports: [ TP MII ]
root at mustang3:/home/steve# ethtool eth3 | grep "Supported ports"
        Supported ports: [ FIBRE ]


-- 
Steve McIntyre, Cambridge, UK.                                steve at einval.com
"When C++ is your hammer, everything looks like a thumb." -- Steven M. Haflich