Ubuntu 上的 ethtool 和 USB 以太网适配器

Question

我正在使用 Ubuntu 12.04，最近我购买了一个 USB 转以太网适配器。

dmesg 命令显示型号为“Davicom DM9601 USB Ethernet”。我无法使用 ethtool 修改其任何设置。

jesin@localhost:~$ sudo ethtool eth1
Settings for eth1:
    Supported ports: [ TP MII ]
    Supported link modes:   10baseT/Half 10baseT/Full 
                            100baseT/Half 100baseT/Full 
    Supported pause frame use: No
    Supports auto-negotiation: Yes
    Advertised link modes:  10baseT/Half 10baseT/Full 
                            100baseT/Half 100baseT/Full 
    Advertised pause frame use: Symmetric Receive-only
    Advertised auto-negotiation: Yes
    Link partner advertised link modes:  10baseT/Half 10baseT/Full 
                                         100baseT/Half 100baseT/Full 
    Link partner advertised pause frame use: Symmetric Receive-only
    Link partner advertised auto-negotiation: Yes
    Speed: 100Mb/s
    Duplex: Full
    Port: MII
    PHYAD: 0
    Transceiver: internal
    Auto-negotiation: on
    Current message level: 0x00000007 (7)
                   drv probe link
    Link detected: yes

当我尝试将适配器的速度更改为 10Mbps 时，我得到了

jesin@localhost:~$ sudo ethtool -s eth1 speed 10
Cannot advertise speed 10

我甚至无法更改端口类型

jesin@localhost:~$ sudo ethtool -s eth1 port tp
Cannot set new settings: Invalid argument
  not setting port

是什么导致了这个问题？

附加信息：

jesin@localhost:~$ sudo ethtool --version
ethtool version 3.1
jesin@localhost:~$ uname -r
3.2.0-39-generic