Windows CE Thread Prioriy

I acquired my Board (TAO3530 - OMAP3530 CPU) from 3rd party vendor (Technexion) , but they seem to use TI's Windows CE 6.0 R3 BSP - from BSQUARE? , So.. would you please help me?

I implemented a gpio pin interrupt in SPI_IOControl function in spi.c device driver using gpio device driver interface, like below.

1) When I create a gpio interrupt event (ISTEvent0) as auto reset, the code works ok.

But when I try to create a gpio interrupt event as manual reset, the below code does not work ok. And GetLastError API call returns 0x57 (invalid parameter) error.

Can I fix this problem?

2) In fact, I want to run the gpio IST as the highest priority thread, but CeSetThreadPriority API call alone looks not enough, because the gpio IST with priority 0 looks delayed even by the lowest priority program execution (like FreeCell.exe) !!

I heard, somwhat vaguely, that above 1) may be the answer

Any idea please?

I attach my code below. Thank you~

==============================================

//------------------------------------------------------------------------------
// global variables

static ECG_DEVICE s_EcgDevice =
    {
    FALSE,
//    DEFAULT_SAMPLE_RATE_HZ,
    0,
    0,
    0
    };

DWORD gIntrEcg        = SYSINTR_NOP;
HANDLE ISTEvent0;
BOOL mytest;

//------------------------------------------------------------------------------
//
//  Function:  SPI_IOControl
//
//  This function sends a command to a device.
//
BOOL SPI_IOControl(
) {
   
 case My_READDATA:
  

  s_EcgDevice.nDrdyGPIO=21;
  s_EcgDevice.hGPIO = GPIOOpen();
  
     // Setup nPENIRQ for input mode, falling edge detect, debounce enable
  GPIOSetMode(s_EcgDevice.hGPIO, s_EcgDevice.nDrdyGPIO, GPIO_DIR_INPUT|GPIO_INT_HIGH_LOW|GPIO_DEBOUNCE_ENABLE);

     // Get the IRQ for the GPIO
  s_EcgDevice.nDrdyIRQ = GPIOGetSystemIrq(s_EcgDevice.hGPIO, s_EcgDevice.nDrdyGPIO);
    
  // why does this routine necessary ?
  GPIOGetMode(s_EcgDevice.hGPIO, s_EcgDevice.nDrdyIRQ);
 
  // Get sysintr values from the OAL for PENIRQ interrupt
  if (!KernelIoControl(
            IOCTL_HAL_REQUEST_SYSINTR,
            &(s_EcgDevice.nDrdyIRQ),
            sizeof(s_EcgDevice.nDrdyIRQ),
            &gIntrEcg,
            sizeof(gIntrEcg),
            NULL
        ) ) ;

  ISTEvent0=CreateEvent(NULL, FALSE, FALSE, NULL);// manual reset --> returne 0x57 error

  mytest = InterruptInitialize(gIntrEcg, ISTEvent0, NULL, 0);

  hThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)DataReadThread, NULL, 0, NULL);

  if(!CeSetThreadPriority(hThread , 0) ) {return 0;}

  break;
    }
}