Questions on 3c59x.c

Jordi Ros
Thu Mar 16 23:01:36 2000

(sorry Donald, I already sent this one to you)


I have an ethernet 3com 905BTX.
I'm reading the 3c59x.c driver because I need to do some measurements. In
particular I would like to:

(1) get statistics of the time it takes for a packet to be transfered from
the NIC buffer to the memory in the PC.
(2) timestamp the time that a packet is sent.

I've been inserting some printk's in the code to discover the different
parts that are executed but I have some questions about it that I would be
very glad if you could please help me to understand:

(1) Can anybody explain me the meaning of this interrupt status ?
RxComplete, UpComplete, TxAvailable, DownComplete, DMADone.

(2) I have seen that the function that handles the reception of a packet is
boomerang_rx. Is the following true?
        - at the begining of boomerang_rx the packet is still in the NIC
buffer but the packet is not in the memory yet.
        - at the end of boomerang_rx the packet is in the memory in a

(3) What is the actual line code that transfer the packet from the NIC
buffer to the memory? is it in
         memcpy(skb_put(skb, pkt_len),
bus_to_virt(le32_to_cpu(vp->rx_ring[entry].addr)), pkt_len);

in boomerand_rx?

and what's the intention for handling the special case of pkt_len <

I would really appreciate any help, since I have not found any documentation
so far on this questions and I'm stuck. Thanks in advance!!!


Jordi Ros                                             email:
Electrical and Computer Engineering      voice (work): (949) 622 0991
University of California, Irvine                  www:

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