DM365 Problem: capture video-> H264codec-> Sending MCBSP EDMA loses XEVT

/********************************************************/
INIT:
(MCBSP_CLKX=2.048MHz)

      davinci_mcbsp_write_reg(DAVINCI_MCBSP_PCR_REG, 0x00000001);
      davinci_mcbsp_write_reg(DAVINCI_MCBSP_SRGR_REG,0);
      davinci_mcbsp_write_reg(DAVINCI_MCBSP_SPCR_REG,0x03000000);


START:

      err = davinci_request_dma (2, "EDMA mcbsp tx",NULL, NULL, &master_ch_tx, &tcc,EVENTQ_0);
      davinci_dma_link_lch(master_ch_tx, master_ch_tx);
      davinci_stop_dma (master_ch_tx);

//      len=edmaparams.bcnt;
      len=256;
      tx_len=len;
      tx_adr=(unsigned long) edmaparams.src;

      davinci_set_dma_src_params (master_ch_tx,(unsigned long) edmaparams.src,0,0);
      davinci_set_dma_dest_params (master_ch_tx,DAVINCI_MCBSP_DXR_REG+DAVINCI_MCBSP_BASE,0,0);
      davinci_set_dma_src_index (master_ch_tx, 2, 0);   //b c
      davinci_set_dma_dest_index (master_ch_tx, 0, 0);  //b c
      davinci_set_dma_transfer_params (master_ch_tx, 2, len, 1, 0, ASYNC);
      davinci_get_dma_params (master_ch_tx, &paramentry);
      davinci_set_dma_params (master_ch_tx, &paramentry);
      if(len<129)
        {
          davinci_mcbsp_write_reg(DAVINCI_MCBSP_XCR_REG, 0x00010040+((len-1)<<8));
        }
      else
        {
          davinci_mcbsp_write_reg(DAVINCI_MCBSP_XCR_REG, 0x00010040+((128-1)<<8)+((len-128-1)<<24)+((0x2)<<21)+(1<<31));
        }

      davinci_start_dma (master_ch_tx);

      w = (davinci_mcbsp_read_reg(DAVINCI_MCBSP_SPCR_REG)&0xfffeffff)|0x10000; // start TX(XRST=1)
      davinci_mcbsp_write_reg(DAVINCI_MCBSP_SPCR_REG,w);

      /* start single signal FSX*/
      gpio_set_value(79, 1);
      gpio_set_value(79, 0);


Wait 1 second:


      davinci_dma_getposition(master_ch_tx, &src, &dst);
      if((tx_adr+(tx_len*2)-2)==src){
          printk(KERN_INFO ">>>Dma_end Ok\n");
        }
      else
        {
          printk(KERN_INFO ">>>Dma_error!!!\n");
        }
      w = davinci_mcbsp_read_reg(DAVINCI_MCBSP_SPCR_REG)&0xFFFEFFFF; // stop TX(XRST=0)
      davinci_mcbsp_write_reg(DAVINCI_MCBSP_SPCR_REG,w);
      davinci_stop_dma (master_ch_tx);
      davinci_free_dma (master_ch_tx);

/********************************************************/


If capture->H264codec->Sending MCBSP   ->>>>Dma_error!!!
If ONLY sending MCBSP                  ->>>>Dma_end Ok

EDMA loses XEVT.
Where a problem?
Thanks.