On Nov 1, 2006, at 10:10 PM, David Young wrote:

> It is because a typical mbuf chain is about three segments long, so  
> you
> need at least three descriptors unless you are willing to copy three
> segments into one.

What the code should do is simply dmamap_load the chain, check to see  
how many DMA segments are ACTUALLY used, and then compare to the  
number of available descriptors.  This is what other network drivers  
in our tree do.

>
> Dave
>
> -- 
> David Young             OJC Technologies
> dyoung@ojctech.com      Urbana, IL * (217) 278-3933

-- thorpej