Help - I am stuck on MCP firmware programming.

Hi,

I am modifying Myrinet MCP firmware to implement a new scheme to bring a 
data, instead of DMA.
The scheme is explained below.
First, I  memory-map a NIC memory into a user application.
And then, a user application writes some data into a memory-mapped area.
I tested memory-mapping and the memory-mapping works well.
Finally, when a user application sends a data from a mmapped area to a 
corresponding program,
a NIC processor fetches data from a NIC memory directly,
 instead of using DMA to bring a data from a main memory into some 
buffer space in a NIC memory

So, I am changing "gm_smda.c", "gm_send.h", "gm_user_dma.h", and 
"gm_send.c".
Especially, I am workng on "gm_sdma.c".

In "shortcut_if_possible" function,  I use "gm_bcopy" to copy the data 
into the payload in a packet,
instead of using USER_SDMA, only if the data is within a mmaped area.
However, it doesn't not work.
A receiver in gm_allsize test only receives one packet from a sender and 
the contents of the received packets is not corret.
So, the receiver couldn't send the reply back to the send.


My code is following. The "if condition" checks whether message is 
within a mmaped area or not.
port->cache is the pointer for a mmapped area in NIC memory.

==============================================================================
if((port->PORT->nic_cache <= message) &&
     ((port->PORT->nic_cache + GM_PORT_MAPPED_CACHE_LEN) > message))
    {

      gm_bcopy(port->cache, payload,send_len) ;
      smlt = (char *)payload + send_len ;  

    }
  else
    {
    USER_SDMA (&payload, message, h+1,
                 send_len + GM_DMA_GRANULARITY-1,
                 GM_SUBPORT_PORT (sp_id), GM_DMA_DESCRIPTOR_E2L);
      smlt = (char *) payload + send_len;
    }
================================================================================

I really appreciate if you tell me what I am missing?

Thanks,

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