Altera TSE driver and example program for lwIP (1.3.2)

I'm happy to run something if you can post some code I can add to the lwIP example and produce the problem. It would determine if it's lwIP options or hardware. Or if it's a real problem with the driver and I'm willing to spend time to try to make it right if I can.

Bill,

Igor,

/* @Function Description -  TSE transmit API to send data to the MAC
 *
 *
 * @API TYPE - Public
 * @param  net  - NET structure associated with the TSE MAC instance
 * @param  data - pointer to the data payload
 * @param  data_bytes - number of bytes of the data payload to be sent to the MAC
 * @return SUCCESS if success, else a negative value
 */
err_t tse_mac_raw_send(struct netif *netif, struct pbuf *pkt)
{
   int                tx_length;
   unsigned           len;
   struct pbuf        *p, *q = NULL;
   alt_u32            *data;
   tse_mac_trans_info *mi;
   lwip_tse_info      *tse_ptr;
   struct ethernetif  *ethernetif;
   unsigned int       *ActualData;
   /* Intermediate buffers used for temporary copy of frames that cannot be directrly DMA'ed*/
   char buf2;
   ethernetif = netif->state;
   tse_ptr = ethernetif->tse_info;
   mi = &tse_ptr->mi;
   if(pkt->next != NULL)        // Unwind pbuf chains
       {
       q = pbuf_alloc(PBUF_RAW, pkt->tot_len, pkt->type);
       for(len = 0, p = pkt; p != NULL; p = p->next)
           {
           memcpy(q->payload + len, p->payload, p->len);
           len += p->len;
           }
       pkt = q;
       }
   for(p = pkt; p != NULL; p = p->next)
      {
      data = p->payload;
      len = p->len;
      if(((unsigned long)data & 0x03) != 0)
         {
         /*
          * Copy data to temporary buffer <buf2>. This is done because of allignment
          * issues. The SGDMA cannot copy the data directly from (data + ETH_PAD_SIZE)
          * because it needs a 32-bit alligned address space.
          */
         memcpy(buf2,data,len);
         data = (alt_u32 *)buf2;
         }
      ActualData = (void *)alt_remap_uncached (data, len<4 ? 4 : len);
      printf("<%d @ 0x%08X/0x%08X>", len, (unsigned int)p->payload, (unsigned int)ActualData);
      if(len<4)
          len=4;
      /* Write data to Tx FIFO using the DMA */
      alt_avalon_sgdma_construct_mem_to_stream_desc(
           (alt_sgdma_descriptor *) &tse_ptr->desc, // descriptor I want to work with
           (alt_sgdma_descriptor *) &tse_ptr->desc,// pointer to "next"
           (alt_u32*)ActualData,                    // starting read address
           (len),                                   //#  bytes
           0,                                       // don't read from constant address
           p == pkt,                                // generate sop
           p->next == NULL,                         // generate endofpacket signal
           0);                                      // atlantic channel (don't know/don't care: set to 0)
      tx_length = tse_mac_sTxWrite(mi,&tse_ptr->desc);
      ethernetif->bytes_sent += tx_length;
      }
   if(q != NULL)
       pbuf_free(q);
   LINK_STATS_INC(link.xmit);
   return ERR_OK;
}

Bill,

err_t tse_mac_raw_send(struct netif *netif, struct pbuf *pkt)
{
   int                tx_length;
   unsigned           len;
   struct pbuf        *p;
   alt_u32            *data;
   tse_mac_trans_info *mi;
   lwip_tse_info      *tse_ptr;
   struct ethernetif  *ethernetif;
   unsigned int       *ActualData;
   int unwind;
   /* Intermediate buffers used for temporary copy of frames that cannot be directrly DMA'ed*/
   struct pbuf unwind_pbuf;
   char buf2;
   ethernetif = netif->state;
   tse_ptr = ethernetif->tse_info;
   mi = &tse_ptr->mi;
   unwind = 0;
   for(p = pkt; p != NULL; p = p->next) {
       if (((unsigned long)p->payload & 0x03) != 0 || p->len < 4 || ((p->len & 3) != 0 && p->next)) {
           unwind = 1;
           break;
       }
   }
   if (unwind) {
       // Unwind pbuf chains
       if (pkt->tot_len > sizeof(buf2)) {
           // no space for unwinding; drop the packet
           return ERR_OK;
       }
       for(len = 0, p = pkt; p != NULL; p = p->next)
           {
             /*
              * Copy data to temporary buffer <buf2>. This is done because of allignment
              * issues. The SGDMA cannot copy the data directly from (data + ETH_PAD_SIZE)
              * because it needs a 32-bit alligned address space.
              */
           memcpy(buf2 + len, p->payload, p->len);
           len += p->len;
           }
       unwind_pbuf.len = unwind_pbuf.tot_len = len;
       unwind_pbuf.payload = buf2;
       unwind_pbuf.next = NULL;
       pkt = &unwind_pbuf;
   }
   for(p = pkt; p != NULL; p = p->next)
      {
      data = p->payload;
      len = p->len;
      // No need for re-alignment and length-checking here
      ActualData = (void *)alt_remap_uncached (data, len);
      //printf("<%d @ 0x%08X/0x%08X>", len, (unsigned int)p->payload, (unsigned int)ActualData);
      /* Write data to Tx FIFO using the DMA */
      alt_avalon_sgdma_construct_mem_to_stream_desc(
           (alt_sgdma_descriptor *) &tse_ptr->desc, // descriptor I want to work with
           (alt_sgdma_descriptor *) &tse_ptr->desc,// pointer to "next"
           (alt_u32*)ActualData,                    // starting read address
           (len),                                   //#  bytes
           0,                                       // don't read from constant address
           p == pkt,                                // generate sop
           p->next == NULL,                         // generate endofpacket signal
           0);                                      // atlantic channel (don't know/don't care: set to 0)
      tx_length = tse_mac_sTxWrite(mi,&tse_ptr->desc);
      ethernetif->bytes_sent += tx_length;
      }
   LINK_STATS_INC(link.xmit);
   return ERR_OK;
}

Maybe you could accumulate the data sent by the user in an aligned buffer until the tcp stack actually sends the data?

Dsl, I think that the easiest application level workaround is simply to not use zero-copy versions of tcp_write and netconn_write. This is appropriate for me because I need TCP for primitive debug console only. Other workarounds are also possible of course.

Guys,

       // Unwind pbuf chains 
       if (pkt->tot_len > sizeof(buf2)) {            // no space for unwinding; drop the packet            
              return ERR_OK;        }

Bill,

       // Unwind pbuf chains 
       if (pkt->tot_len > sizeof(buf2)) {            // no space for unwinding; drop the packet            
              return ERR_OK;        }

Igor,

There may be a much faster way to handle these 1-3 byte SGDMA transfers.