help required .... (C function does not return)

#include <16F877A.h>
#fuses NOWDT,NOLVP,NODEBUG,NOPUT,HS
#use delay(clock=40000000)
#use rs232(baud=9600,rcv=PIN_C7,xmit=PIN_C6)
#include <flexlcd.c>

int loop=0;
char cmd[26];
char ch;
volatile char data[20] ;

void serial(void)
{
  char commaCount = 0;

  char done = 0;
  char count=0;
  char LL;
 
  for(LL=0;LL<2;LL++)     //Loop 2 times for Longitude and Latitude strings
  {
    while(!done)       //Wait until beginning of new printf
    {
      data[0] = getch();
      if(data[0] == '$') done = 1;
    }
    done = 0;
    data[0] = 0;

    while(!done)       //wait until we get out first comma
    {
      data[0] = getch();
      if(data[0] == 0x2C) done = 1;
    }
    done = 0;
    data[0] = 0;

    while(commaCount < 4) // This is the amount of data we need... 4 commas worth
    {
      count=0;            //count variable for placing data in loop
      while(!done)            //loop getting all data possible
      {
        data[count] = getch(); //place data into variable
        count++;               //Increase count
   
        if(data[count] = ',')  //if data is a command break the loop
          done = 1;
      }
      commaCount++;            //Loop is broken so increase the comma count
    }
  }
}

void main(void)
{
  set_tris_c(0b10000000);
  set_tris_D(0x00);
  lcd_init();
  delay_ms(20);

  while(1)
  {
    serial();

  	lcd_gotoxy(1,1);
  	printf(lcd_putc,"LAT=%c%c%c%c%c%c%c%c%c%c%c \n",cmd[1],cmd[2],cmd[3],cmd[4],cmd[5],cmd[6],cmd[7],cmd[8],cmd[9],cmd[10],cmd[11]);
  	lcd_gotoxy(1,2);
  	printf(lcd_putc,"LON=%c%c%c%c%c%c%c%c%c%c%c%c",cmd[13],cmd[14],cmd[15],cmd[16],cmd[17],cmd[18],cmd[19],cmd[20],cmd[21],cmd[22],cmd[23],cmd[24]);
  }
}