APPRO ipnc36x mt9p031 cannot output flash strobe pulse in snapshot mode sometime

Hi, everyone,

      I can switch ipnc-mt5 to snapshot mode, trigger  it and get the snapshot picture normal.

But sometimes, the image sensor cannot output flash strobe when I have set READ_MODE_1 register's STROBE bit.

following is my code,

int DRV_imgsSetShutterMode(Uint8 exp_mode, Uint32 exp_time, Uint8 flash, Uint8 flash_time, int gain)
{
  static Uint8 lastRegAddr[2] = {SHUTTER_WIDTH_L, GAIN_GLOBAL};
  static Uint16 lastRegValue[2];

  Uint8 regAddr[8];
  Uint16 regValue[8], read_mode_1, output_ctrl;
  Uint32 regDelay[8] = {0};
  int status, i = 0;

#if 0
  regAddr[0] = OUTPUT_CTRL;
  status = DRV_i2cRead16(&gDRV_imgsObj.i2cHndl, &regAddr[0], &output_ctrl, 1);
  if(status!=OSA_SOK) {
    OSA_ERROR("DRV_i2cRead16() output_ctrl\n");
    return status;
  }
  OSA_printf("out_ctrl:0x%x\n", output_ctrl);
#endif

  regAddr[0] = READ_MODE_1;
  status = DRV_i2cRead16(&gDRV_imgsObj.i2cHndl, &regAddr[0], &read_mode_1, 1);
  if(status!=OSA_SOK) {
    OSA_ERROR("DRV_i2cRead16() read_mode_1\n");
    return status;
  }
#if 0
    regAddr[i] = OUTPUT_CTRL;
    regValue[i] = (output_ctrl | 0x01);
    i++;
#endif

    regAddr[i] = RESTART;
    regValue[i] = 0x03;
    i++;

  if(exp_time > 0)
  {
     DRV_ImgsFrameTime *pFrame = &gDRV_imgsObj.curFrameTime;

     regAddr[i] = SHUTTER_WIDTH_L;
     regValue[i] = (exp_time*1000.0 + pFrame->shutterOverhead)/pFrame->t_row;
     if(regValue[i]<1)
        regValue[i] = 1;
     if(regValue[i]>=64*1024-1)
        regValue[i] = 64*1024 - 1;

     i++;
  }
  if(gain > 0)
  {
     regAddr[i] = GAIN_GLOBAL;
     regValue[i] = DRV_imgsCalcAgain(gain);

     i++;
  }

  switch(exp_mode)
  {
    case IMG_EXPO_MODE_ERS:

    status = DRV_i2cRead16(&gDRV_imgsObj.i2cHndl, lastRegAddr, lastRegValue, 2);

    regAddr[i] = READ_MODE_1;
    read_mode_1 |= (1 << SNAPSHOT_BITMASK);
    read_mode_1 &= ~(1 << GLOBALRESET_BITMASK);
    if(flash)
    {
       read_mode_1 |= (1 << STROBE_BITMASK);
       read_mode_1 |= flash_time;
    }
    else
    {
       read_mode_1 &= ~(1 << STROBE_BITMASK);
    }
    regValue[i] = read_mode_1;
    i++;

    regAddr[i] = RESTART;
    regValue[i] = 0x05;
    i++;

    break;
   
    case IMG_EXPO_MODE_GRR:

    status = DRV_i2cRead16(&gDRV_imgsObj.i2cHndl, lastRegAddr, lastRegValue, 2);

    regAddr[i] = READ_MODE_1;
    read_mode_1 |= (1 << SNAPSHOT_BITMASK);
    read_mode_1 |= (1 << GLOBALRESET_BITMASK);
    if(flash)
    {
       read_mode_1 |= (1 << STROBE_BITMASK);
       read_mode_1 |= flash_time;
    }
    else
    {
       read_mode_1 &= ~(1 << STROBE_BITMASK);
    }
    regValue[i] = read_mode_1;
    i++;

    regAddr[i] = RESTART;
    regValue[i] = 0x05;
    i++;

#if 0

    usleep(gain * 1000);

    regAddr[i] = RESTART;
    regValue[i] = 0x05;
    i++;
#endif

#if 0
#if 1
    regAddr[i] = READ_MODE_1;
    read_mode_1 &= ~(1 << STROBE_BITMASK);
    regValue[i] = read_mode_1;
    i++;
#endif

  {
     DRV_ImgsFrameTime *pFrame = &gDRV_imgsObj.curFrameTime;

     regAddr[i] = SHUTTER_WIDTH_L;
     regValue[i] = (1000*1000.0 + pFrame->shutterOverhead)/pFrame->t_row;
     if(regValue[i]<1)
        regValue[i] = 1;
     if(regValue[i]>=64*1024-1)
        regValue[i] = 64*1024 - 1;

     i++;
  }

    regAddr[i] = RESTART;
    regValue[i] = 0x05;
    regDelay[i] = 0;
    i++;
#endif
    break;

    case IMG_EXPO_MODE_CONT:
    default:

    regAddr[i] = lastRegAddr[0];
    regValue[i] = lastRegValue[0];
    i++;
    regAddr[i] = lastRegAddr[1];
    regValue[i] = lastRegValue[1];
    i++;

    regAddr[i] = READ_MODE_1;
    read_mode_1 &= ~(1 << SNAPSHOT_BITMASK);
    read_mode_1 &= ~(1 << STROBE_BITMASK);
    regValue[i] = read_mode_1;
    i++;
    regAddr[i] = RESTART;
    regValue[i] = 0x01;
    i++;

    DRV_imgsSetSnaping(0);

  }

  status = _DRV_i2cWrite16(&gDRV_imgsObj.i2cHndl, &regAddr[0], &regValue[0], 0, i);
//  status = _DRV_i2cWrite16(&gDRV_imgsObj.i2cHndl, &regAddr[0], &regValue[0], &regDelay[0], i);

  if(status!=OSA_SOK) {
    OSA_ERROR("DRV_i2cWrite16()\n");
    return status;
  }
  CSL_gpioClr(&gCSL_gpioHndl, 81);//GIO_ALARM_OUT);
  OSA_printf("snap em:%d, et:%d, fl:%d, ft:%d, gn:%d\n",
      exp_mode, exp_time, flash, flash_time, gain);

  return status;
}