RTOS/AM5728: GPIO interrupt response is slow

/**
 *  \file   main.c
 *
 *  \brief  Example application main file. This application will toggle the led.
 *          The led toggling will be done inside an callback function, which
 *          will be called by Interrupt Service Routine. Interrupts are
 *          triggered manually and no external source is used to trigger
 *          interrupts.
 *
 */

/*
 * Copyright (C) 2014 - 2016 Texas Instruments Incorporated - http://www.ti.com/
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright
 * notice, this list of conditions and the following disclaimer in the
 * documentation and/or other materials provided with the
 * distribution.
 *
 * Neither the name of Texas Instruments Incorporated nor the names of
 * its contributors may be used to endorse or promote products derived
 * from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */


#ifndef BARE_METAL
/* XDCtools Header files */
#include <xdc/std.h>
#include <xdc/cfg/global.h>
#include <xdc/runtime/System.h>
#include <xdc/runtime/Error.h>


/* BIOS Header files */
#include <ti/sysbios/BIOS.h>
#include <ti/sysbios/knl/Task.h>
#endif

#include <stdio.h>

/* TI-RTOS Header files */
#include <ti/drv/gpio/GPIO.h>
#include <ti/drv/gpio/soc/GPIO_soc.h>

#include "GPIO_log.h"
#include "GPIO_board.h"

#include <ti/board/board.h>
#include <c6x.h>

/**********************************************************************
 ************************** Macros ************************************
 **********************************************************************/
#if defined(SOC_AM572x) || defined (SOC_AM571x)
#if defined (__TI_ARM_V7M4__)
#define DELAY_VALUE       (0x6FFFFFU) /* Update Delay as it is not sufficent for M4 core */
#else
#define DELAY_VALUE       (0x6FFFFFU)
#endif
#else
#define DELAY_VALUE       (0x6FFFFFU)
#endif

/**********************************************************************
 ************************** Internal functions ************************
 **********************************************************************/

/* Delay function */
void AppDelay(unsigned int delayVal);

/* Callback function */
void AppGpioCallbackFxn(void);

#if defined(IDK_AM572X) || defined(IDK_AM571X)
/* GPIO clock and pinmux configurations */
extern void AppGPIOInit(void);
#endif

#if defined(IDK_AM572X)
extern void GPIOApp_UpdateBoardInfo(void);
extern void GPIOAppUpdateConfig(uint32_t *gpioBaseAddr, uint32_t *gpioPin);
#endif

/*
 *  ======== Board_initI2C ========
 */
static void Board_initGPIO(void)
{
    Board_initCfg boardCfg;

#if defined(SOC_K2H) || defined(SOC_K2K) || defined(SOC_K2E) || defined(SOC_K2L) || defined(SOC_K2G) || defined(SOC_C6678) || defined(SOC_C6657)
    GPIO_v0_HwAttrs gpio_cfg;

    /* Get the default SPI init configurations */
    GPIO_socGetInitCfg(GPIO_LED0_PORT_NUM, &gpio_cfg);

    /* Modify the default GPIO configurations if necessary */

    /* Set the default GPIO init configurations */
    GPIO_socSetInitCfg(GPIO_LED0_PORT_NUM, &gpio_cfg);

#if defined(SOC_K2G)
    /* Setup GPIO interrupt configurations */
    GPIO_socSetIntMux(GPIO_LED0_PORT_NUM, GPIO_LED0_PIN_NUM, NULL, GPIO_MUX_SEL);
#endif
#endif

#if defined(EVM_K2E) || defined(EVM_C6678)
    boardCfg = BOARD_INIT_MODULE_CLOCK |
        BOARD_INIT_UART_STDIO;
#else
    boardCfg = BOARD_INIT_PINMUX_CONFIG |
        BOARD_INIT_MODULE_CLOCK |
        BOARD_INIT_UART_STDIO;
#endif
    Board_init(boardCfg);

#if defined(IDK_AM572X)
    GPIOApp_UpdateBoardInfo();
#endif
}

/**********************************************************************
 ************************** Global Variables **************************
 **********************************************************************/
volatile uint32_t gpio_intr_triggered = 0, callback_counter = 0;
uint32_t buffer1[32], buffer2[32], diff[32];
uint32_t gpioBaseAddr;
uint32_t gpioPin;

/*
 *  ======== test function ========
 */
#ifndef BARE_METAL
void gpio_test(UArg arg0, UArg arg1)
{
#else
void main()
{
    Board_initGPIO();
#endif
    uint32_t testOutput = 1;
    uint32_t loop = 0, index;

    /* GPIO initialization */
    GPIO_init();

    /* Set the callback function */
    GPIO_setCallback(USER_LED0, AppGpioCallbackFxn);

    /* Enable GPIO interrupt on the specific gpio pin */
    GPIO_enableInt(USER_LED0);

    /* Write high to gpio pin to control LED1 */
    GPIO_write((USER_LED1), GPIO_PIN_VAL_HIGH);
    AppDelay(DELAY_VALUE);

    GPIO_log("\n GPIO Led Blink Application \n");

#if defined(SOC_K2L) || defined(SOC_C6678) || defined(SOC_C6657)
    /* No GPIO pin directly connected to user LED's on K2L/K2G/C6678/C6657 EVM, just trigger interrupt once */
    GPIO_toggle(USER_LED0);
    while (!gpio_intr_triggered);

    GPIO_log("\n All tests have passed \n");
#else

    while(loop < 10)
    {
#if defined(SOC_AM572x) || defined(SOC_AM571x)|| defined(SOC_AM335x) || defined(SOC_AM437x)

#if defined (IDK_AM572X)
        /* Update GPIO info based on the board */
        GPIOAppUpdateConfig(&gpioBaseAddr, &gpioPin);
#else
        gpioBaseAddr = GPIO_BASE_ADDR;
        gpioPin      = GPIO_LED_PIN;
#endif
        /* Trigger interrupt */
        buffer1[loop] =  TSCL;
        GPIOTriggerPinInt(gpioBaseAddr, 0, gpioPin);

#endif
#if defined(SOC_K2H) || defined(SOC_K2K) || defined(SOC_K2E) || defined(SOC_K2G)
        GPIO_toggle(USER_LED0);
#endif
        AppDelay(1000000);
        loop ++;
    }
    for (index = 0; index < 10; index++) {
        diff[index] = buffer2[index+1] - buffer1[index];
    }
#endif
    Task_exit();
}

#ifndef BARE_METAL
/*
 *  ======== main ========
 */
int main(void)
{
    /* Call board init functions */
	TSCL = 1;
    Board_initGPIO();

#if defined(IDK_AM572X) || defined(IDK_AM571X)
    AppGPIOInit();
#endif

    /* Start BIOS */
    BIOS_start();
    return (0);
}
#endif

/*
 *  ======== AppDelay ========
 */
void AppDelay(unsigned int delayVal)
{
	uint32_t start = TSCL;

	while ((TSCL - start) < delayVal);
}

/*
 *  ======== Callback function ========
 */
void AppGpioCallbackFxn(void)
{
    /* Toggle LED1 */
    //GPIO_toggle(USER_LED1);
    //AppDelay(8400);
    //gpio_intr_triggered = 1;
    buffer2[callback_counter] = TSCL;
    callback_counter ++;
}