TI-RTOS-MCU: SWI_Post() call in HWI function results in Posting of the SWI but not executing the function

Hi,

  Do you have BIOS_start() called at the end of your main()? Without BIOS_start(), the OS kernel will not schedule for the SWI to run. Look at this  below example. It is an example for TM4C123 but has the same concept of usage for TM4C129. A HWI is created to handle the Timer interrupt. When there is an timer interrupt, it calls Swi_post to run the LED function. 

//----------------------------------------
// BIOS header files
//----------------------------------------
#include <xdc/std.h>  						//mandatory - have to include first, for BIOS types
#include <ti/sysbios/BIOS.h> 				//mandatory - if you call APIs like BIOS_start()
#include <xdc/runtime/Log.h>				//needed for any Log_info() call
#include <xdc/cfg/global.h> 				//header file for statically defined objects/handles
#include <xdc/runtime/System.h>
#include <xdc/runtime/Error.h>
#include <ti/sysbios/hal/Hwi.h>


//------------------------------------------
// TivaWare Header Files
//------------------------------------------
#include <stdint.h>
#include <stdbool.h>

#include "inc/hw_types.h"
#include "inc/hw_memmap.h"
#include "driverlib/sysctl.h"
#include "driverlib/gpio.h"
#include "inc/hw_ints.h"
#include "driverlib/interrupt.h"
#include "driverlib/timer.h"


//----------------------------------------
// Prototypes
//----------------------------------------
void hardware_init(void);
void ledToggle(void);
void Timer_ISR(void);


//---------------------------------------
// Globals
//---------------------------------------
volatile int16_t i16ToggleCount = 0;


//---------------------------------------------------------------------------
// main()
//---------------------------------------------------------------------------
void main(void)
{
    Hwi_Params hwiParams;
    Hwi_Handle myHwi;
    Error_Block eb;
    /* Initialize error block and hwiParams to default values */
    Error_init(&eb);
    Hwi_Params_init(&hwiParams);
    hwiParams.enableInt = FALSE;
    /* Create Hwi on vector 51 which is the TIMER3A */
    myHwi = Hwi_create(51, (Hwi_FuncPtr)Timer_ISR, &hwiParams, &eb);
    if (myHwi == NULL) {
    System_abort("Hwi create failed");
    }
    Hwi_enableInterrupt(51);


    Swi_Params swiParams;
     Swi_Handle LEDSwi;
     Error_Block eb2;
     /* Initialize error block and hwiParams to default values */
     Error_init(&eb2);
     Swi_Params_init(&swiParams);
     LEDSwi = Swi_create((Swi_FuncPtr)ledToggle, &swiParams, &eb2);
     if (LEDSwi == NULL) {
     System_abort("Swi create failed");
     }


   hardware_init();							// init hardware via Xware

   BIOS_start();

}


//---------------------------------------------------------------------------
// hardware_init()
//
// inits GPIO pins for toggling the LED
//---------------------------------------------------------------------------
void hardware_init(void)
{
	uint32_t ui32Period;

	//Set CPU Clock to 40MHz. 400MHz PLL/2 = 200 DIV 5 = 40MHz
	SysCtlClockSet(SYSCTL_SYSDIV_5|SYSCTL_USE_PLL|SYSCTL_XTAL_16MHZ|SYSCTL_OSC_MAIN);

	// ADD Tiva-C GPIO setup - enables port, sets pins 1-3 (RGB) pins for output
	SysCtlPeripheralEnable(SYSCTL_PERIPH_GPIOF);
	GPIOPinTypeGPIOOutput(GPIO_PORTF_BASE, GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3);

	// Turn on the LED
	GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3, 4);

	// Timer 2 setup code
	SysCtlPeripheralEnable(SYSCTL_PERIPH_TIMER3);			// enable Timer 3 periph clks
	TimerConfigure(TIMER3_BASE, TIMER_CFG_PERIODIC);		// cfg Timer 3 mode - periodic

	ui32Period = (SysCtlClockGet() /2);						// period = CPU clk div 2 (500ms)
	TimerLoadSet(TIMER3_BASE, TIMER_A, ui32Period);			// set Timer 3 period

	TimerIntEnable(TIMER3_BASE, TIMER_TIMA_TIMEOUT);		// enables Timer 3 to interrupt CPU

	TimerEnable(TIMER3_BASE, TIMER_A);						// enable Timer 3

}


//---------------------------------------------------------------------------
// ledToggle()
//
// toggles LED on Tiva-C LaunchPad
//---------------------------------------------------------------------------
void ledToggle(void)
{
	// LED values - 2=RED, 4=BLUE, 8=GREEN
	if(GPIOPinRead(GPIO_PORTF_BASE, GPIO_PIN_2))
	{
		GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_1|GPIO_PIN_2|GPIO_PIN_3, 0);
	}
	else
	{
		GPIOPinWrite(GPIO_PORTF_BASE, GPIO_PIN_2, 4);
	}

	i16ToggleCount += 1;									// keep track of #toggles

	Log_info1("LED TOGGLED [%u] TIMES",i16ToggleCount);		// send toggle count to UIA

}


//---------------------------------------------------------------------------
// Timer ISR - called by BIOS Hwi (see app.cfg)
//
// Posts Swi (or later a Semaphore) to toggle the LED
//---------------------------------------------------------------------------
void Timer_ISR(void)
{
    TimerIntClear(TIMER3_BASE, TIMER_TIMA_TIMEOUT);			// must clear timer flag FROM timer

	Swi_post(LEDSwi);										// post LEDSwi
}