BUG: i.MX6-FEC: broken TCP tx checksumming

[Holger Schurig]

> hat's again read via the generic phy layer, and that suggests that
> the phy finally reported the correct speed... again, I wonder if
> something in the phy layer is buggy.

It's just miitool that is broken. When the link is up & ready, this happens:

root at mde:~# ethtool eth0
Settings for eth0:
Supported ports: [ TP MII ]
Supported link modes:   10baseT/Half 10baseT/Full
                       100baseT/Half 100baseT/Full
Supported pause frame use: Symmetric
Supports auto-negotiation: Yes
Advertised link modes:  10baseT/Half 10baseT/Full
                       100baseT/Half 100baseT/Full
Advertised pause frame use: Symmetric
Advertised auto-negotiation: Yes
Link partner advertised link modes:  10baseT/Half 10baseT/Full
                                    100baseT/Half 100baseT/Full
Link partner advertised pause frame use: Symmetric
Link partner advertised auto-negotiation: Yes
Speed: 100Mb/s
Duplex: Full
Port: MII
PHYAD: 0
Transceiver: external
Auto-negotiation: on
Link detected: yes
root at mde:~# mii-tool eth0
eth0: negotiated 1000baseT-HD flow-control, link ok

Seems also that things in /sys/class/net are ok:

root at mde:~# cat /sys/class/net/eth0/speed
100
root at mde:~# cat /sys/class/net/eth0/duplex
full

mii-tool calls (according to strace) SIOCGMIIPHY, whereas ethtool uses
SIOCETHTOOL.