Not all chips/drivers are mii compliant.  Even newer ones. 
You should be able to get info on yours from scyld.com.

Raymond Norton wrote:

>>Are you using ethtool or mii-tool to make the settings?
>>
>>    
>>
>
>
>I tried using ethtool,but get the folowing:
>
>ethtool -s eth0 speed 100 duplex full autoneg off
>Cannot get current device settings: Operation not supported
>  not setting speed
>  not setting duplex
>  not setting autoneg
>
>
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>
>  
>