PIC32MK1024MCM064 gets stuck in timer2 ISR - timer

Question

I am beginner exploring PIC32MK1024MCM064 timers. Just want to write simple code with self triggering timer and some main program in the background. So I achieved my code to get into the ISR part, but the code gets stuck in the ISR after first time interrupt event. The code does not come back to the main loop with blinking leds. I investigated the datasheet quite well, but besides clearing the interrupt flag, I don`t know what to do else. I really thank you in advance for any help provided
// DEVCFG3
#pragma config USERID = 0xFFFF // Enter Hexadecimal value (Enter Hexadecimal value)
#pragma config PWMLOCK = OFF // PWM IOxCON lock (PWM IOxCON register writes accesses are not locked or protected)
#pragma config FUSBIDIO2 = ON // USB2 USBID Selection (USBID pin is controlled by the USB2 module)
#pragma config FVBUSIO2 = ON // USB2 VBUSON Selection bit (VBUSON pin is controlled by the USB2 module)
#pragma config PGL1WAY = OFF // Permission Group Lock One Way Configuration bit (Allow multiple reconfigurations)
#pragma config PMDL1WAY = OFF // Peripheral Module Disable Configuration (Allow multiple reconfigurations)
#pragma config IOL1WAY = OFF // Peripheral Pin Select Configuration (Allow multiple reconfigurations)
#pragma config FUSBIDIO1 = ON // USB1 USBID Selection (USBID pin is controlled by the USB1 module)
#pragma config FVBUSIO1 = ON // USB2 VBUSON Selection bit (VBUSON pin is controlled by the USB1 module)
// DEVCFG2
#pragma config FPLLIDIV = DIV_1 // System PLL Input Divider (1x Divider)
#pragma config FPLLRNG = RANGE_BYPASS // System PLL Input Range (Bypass)
#pragma config FPLLICLK = PLL_FRC // System PLL Input Clock Selection (FRC is input to the System PLL)
#pragma config FPLLMULT = MUL_2 // System PLL Multiplier (PLL Multiply by 1)
#pragma config FPLLODIV = DIV_2 // System PLL Output Clock Divider (2x Divider)
#pragma config BORSEL = HIGH // Brown-out trip voltage (BOR trip voltage 2.1v (Non-OPAMP deviced operation))
#pragma config UPLLEN = OFF // USB PLL Enable (USB PLL Disabled)
// DEVCFG1
#pragma config FNOSC = FRC // Oscillator Selection Bits (Internal Fast RC (FRC))
#pragma config DMTINTV = WIN_0 // DMT Count Window Interval (Window/Interval value is zero)
#pragma config FSOSCEN = OFF // Secondary Oscillator Enable (Disable Secondary Oscillator)
#pragma config IESO = OFF // Internal/External Switch Over (Disabled)
#pragma config POSCMOD = OFF // Primary Oscillator Configuration (Primary osc disabled)
#pragma config OSCIOFNC = OFF // CLKO Output Signal Active on the OSCO Pin (Disabled)
#pragma config FCKSM = CSDCMD // Clock Switching and Monitor Selection (Clock Switch Disabled, FSCM Disabled)
#pragma config WDTPS = PS1 // Watchdog Timer Postscaler (1:1)
#pragma config WDTSPGM = STOP // Watchdog Timer Stop During Flash Programming (WDT stops during Flash programming)
#pragma config WINDIS = NORMAL // Watchdog Timer Window Mode (Watchdog Timer is in non-Window mode)
#pragma config FWDTEN = OFF // Watchdog Timer Enable (WDT Disabled)
#pragma config FWDTWINSZ = WINSZ_25 // Watchdog Timer Window Size (Window size is 25%)
#pragma config DMTCNT = DMT31 // Deadman Timer Count Selection (2^31 (2147483648))
#pragma config FDMTEN = OFF // Deadman Timer Enable (Deadman Timer is disabled)
// DEVCFG0
#pragma config DEBUG = OFF // Background Debugger Enable (Debugger is disabled)
#pragma config JTAGEN = OFF // JTAG Enable (JTAG Disabled)
#pragma config ICESEL = ICS_PGx3 // ICE/ICD Comm Channel Select (Communicate on PGEC3/PGED3)
#pragma config TRCEN = OFF // Trace Enable (Trace features in the CPU are disabled)
#pragma config BOOTISA = MIPS32 // Boot ISA Selection (Boot code and Exception code is MIPS32)
#pragma config FECCCON = ECC_DECC_DISABLE_ECCON_WRITABLE// Dynamic Flash ECC Configuration Bits (ECC and Dynamic ECC are disabled (ECCCON<1:0> bits are writable))
#pragma config FSLEEP = OFF // Flash Sleep Mode (Flash is powered down when the device is in Sleep mode)
#pragma config DBGPER = PG_ALL // Debug Mode CPU Access Permission (Allow CPU access to all permission regions)
#pragma config SMCLR = MCLR_NORM // Soft Master Clear Enable (MCLR pin generates a normal system Reset)
#pragma config SOSCGAIN = G3 // Secondary Oscillator Gain Control bits (Gain is G3)
#pragma config SOSCBOOST = ON // Secondary Oscillator Boost Kick Start Enable bit (Boost the kick start of the oscillator)
#pragma config POSCGAIN = G3 // Primary Oscillator Coarse Gain Control bits (Gain Level 3 (highest))
#pragma config POSCBOOST = ON // Primary Oscillator Boost Kick Start Enable bit (Boost the kick start of the oscillator)
#pragma config POSCFGAIN = G3 // Primary Oscillator Fine Gain Control bits (Gain is G3)
#pragma config POSCAGCDLY = AGCRNG_x_25ms// AGC Gain Search Step Settling Time Control (Settling time = 25ms x AGCRNG)
#pragma config POSCAGCRNG = ONE_X // AGC Lock Range bit (Range 1x)
#pragma config POSCAGC = Automatic // Primary Oscillator Gain Control bit (Automatic Gain Control for Oscillator)
#pragma config EJTAGBEN = NORMAL // EJTAG Boot Enable (Normal EJTAG functionality)
// DEVCP
#pragma config CP = OFF // Code Protect (Protection Disabled)
// SEQ
#pragma config TSEQ = 0x0 // Boot Flash True Sequence Number (Enter Hexadecimal value)
#pragma config CSEQ = 0xFFFF // Boot Flash Complement Sequence Number (Enter Hexadecimal value)
//-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
#include <xc.h>
#include <toolchain_specifics.h>
#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdlib.h>
#include "stdio.h"
#include <sys/attribs.h>
//-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
#define CPU_CLOCK_FREQUENCY 8000000
#define _CP0_GET_COUNT() _mfc0 (_CP0_COUNT, _CP0_COUNT_SELECT)
//------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
void delay_ms ( uint32_t delay_ms)
{
uint32_t startCount, endCount;
endCount=((CPU_CLOCK_FREQUENCY/1000)*delay_ms)/2;
startCount=_CP0_GET_COUNT();
while((_CP0_GET_COUNT()-startCount)<endCount);
}
//-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
void Timer2_setup(void){
PB2DIVbits.ON = 0b0; //PB2CLK is disabled
PB2DIVbits.PBDIVRDY = 0b1; //Enabling the PBDIV configuration
PB2DIVbits.PBDIV = 0b0000000; //PBCLKx is SYSCLK divided by 128
PB2DIVbits.PBDIVRDY = 0b0; //Disabling the PBDIV configuration
PB2DIVbits.ON = 0b1; //PB2CLK is enabled
//----------------------------------------------------
T2CONbits.ON = 0b0; //Timer2 is disabled
T2CONbits.TCS = 0b0; //Internal peripheral clock
T2CONbits.T32 = 0b1; //Timer2 is set to 32 bits
T2CONbits.TCKPS = 0b101; //1:256 prescale value
T2CONbits.SIDL = 0b1; //Timer2 does not work in idle mode
TMR2 = 0x0; //Clear counter
PR2 = 124999U; //Timer2 period is set to 1000 milliseconds
//----------------------------------------------------
//Interrupt setup
IEC0bits.T2IE = 0b1; //Enable timer interrupt
IPC2bits.T2IP = 0b001; //Interrupt priority set to 1
}
//-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
int main ( void )
{
TRISAbits.TRISA7 = 0;
LATAbits.LATA7 = 0;
TRISBbits.TRISB14 = 0;
LATBbits.LATB14 = 0;
TRISBbits.TRISB15 = 0;
LATBbits.LATB15 = 0;
Timer2_setup();
__builtin_enable_interrupts(); // VERY IMPORTANT Built in macro function to globally enable interrupts
T2CONbits.ON = 0b1; //Timer2 is enabled
while (1)
{
LATBbits.LATB14 = 1;
delay_ms(300);
LATBbits.LATB14 = 0;
LATBbits.LATB15 = 1;
delay_ms(300);
LATBbits.LATB15 = 0;
}
return (EXIT_FAILURE);
}
//INTERRUPTS-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
void __ISR( _TIMER_2_VECTOR, IPL1SRS) Timer2_Handler (void){
T2CONbits.ON = 0b0; //Timer2 is disabled
TMR2 = 0x0; //Clear counter
LATAbits.LATA7 = 1;
delay_ms(300); //Interrupt indicator
LATAbits.LATA7 = 0;
IFS0bits.T2IF = 0b0; //Clear input change interrupt
T2CONbits.ON = 0b1; //Timer2 is enabled
}

Answer 1

You most definitely shouldn't call delay_ms() in your interrupt handler. I'm fairly sure that this is the reason of your problem. IRQ handlers should be as quick as possible.
Check out https://www.aidanmocke.com/blog/2018/11/15/timers/. This whole blog is great for learning firmware development on PIC32.